Doctor of Philosophy, Leiden University (2016)
Master of Science, Vrije Universiteit Amsterdam (2011)
Bachelor of Science, Vrije Universiteit Amsterdam (2009)
Identification of lymph node (LN) metastasis is essential for staging of solid tumors, and as a result, surgeons focus on harvesting significant numbers of LNs during ablative procedures for pathological evaluation. Isolating those LNs most likely to harbor metastatic disease can allow for a more rigorous evaluation of fewer LNs. Here we evaluate the impact of a systemically injected, near-infrared fluorescently-labeled, tumor-targeting contrast agent, panitumumab-IRDye800CW, to facilitate the identification of metastatic LNs in the ex vivo setting for head and neck cancer patients. Molecular imaging demonstrates a significantly higher mean fluorescence signal in metastatic LNs compared to benign LNs in head and neck cancer patients undergoing an elective neck dissection. Molecular imaging to preselect at-risk LNs may thus allow a more rigorous examination of LNs and subsequently lead to improved prognostication than regular neck dissection.
View details for DOI 10.1038/s41467-019-13076-7
View details for PubMedID 31695030
BACKGROUND: Despite the rapid growth of fluorescence imaging, accurate sampling of tissue sections remains challenging. Development of novel technologies to improve intraoperative assessment of tissue is needed.METHODS: A novel contact probe-based fluorescence dosimeter device, optimized for IRDye800CW quantification, was developed. After evaluation of the device in a phantom setup, its clinical value was defined ex vivo in patients with head and neck squamous cell carcinoma who received panitumumab-IRDye800CW.RESULTS: Ten patients were enrolled with a total of 216 data points obtained. Final histopathology showed tumor in 119 spots and normal tissue in 97 spots. Fluorescence-to-excitation ratios in tumor tissue were more than three times higher than those in normal tissue. The area under the curve was 0.86 (95% CI: 0.81-0.91) for tumor detection.CONCLUSIONS: Fluorescence-guided tissue preselection using a fluorescence dosimeter could have substantial impact on tissue sampling for frozen section analysis and potentially reduce sampling errors.
View details for DOI 10.1002/hed.25964
View details for PubMedID 31571335
OBJECTIVE: High-grade dysplasia is associated with a risk of malignant transformation, and it is necessary to distinguish from normal epithelium or low-grade dysplasia, especially in the intraoperative setting. We hypothesize that an anti-epidermal growth factor receptor (EGFR) contrast agent can be used to differentiate high-grade dysplasia from low-grade dysplasia and normal epithelium.MATERIALS AND METHODS: Patients with biopsy proven head and neck squamous cell carcinoma (HNSCC) were enrolled in a clinical trial using systemically injected fluorescently labeled anti-EGFR antibody (panitumumab-IRDye800CW) (NCT02415881). Paraffin embedded tumor specimens from 11 patients were evaluated by fluorescence histopathology. Hematoxylin and eosin (H&E) slides were reviewed by a board-certified pathologist, and regions of invasive squamous cell carcinoma, high-grade dysplasia and low-grade dysplasia were delineated. EGFR expression was assessed for each patient by way of immunohistochemistry.RESULTS: 11 patients were included in the study with a total of 219 areas on tissue sections analyzed; 68 normal epithelium, 53 low-grade dysplasia, 48 high-grade dysplasia, and 50 malignant regions. The signal-to-background ratio (SBR) increased proportionally with increasing grade of dysplasia; normal epithelium (1.5?±?0.1), low-grade dysplasia (1.8?±?0.1), high-grade dysplasia: (2.3?±?0.2). High-grade dysplasia had a significantly higher SBR when compared to normal or low-grade dysplasia (p?0.05). Fluorescence histopathology positively correlated with EGFR expression by immunohistochemistry, which also increased proportionally with increasing degree of dysplasia.CONCLUSION: Molecular imaging with an anti-EGFR agent can successfully discriminate high-grade dysplastic lesions from low-grade dysplasia and normal epithelium.
View details for DOI 10.1016/j.oraloncology.2019.08.008
View details for PubMedID 31421471
PURPOSE: Despite major advancements in surgical oncology, the positive margin rate for primary head and neck cancer resection remains around 15-30%. In particular, the deep surface margin is the most challenging to adequately assess. Inadequate margins are directly correlated to poor survival, and as such, mitigation of these rates is critical to improve patient outcomes. We have developed an ex vivo imaging strategy that utilizes fluorescence intensity-peaks (relative to background signal) of an injected anti-epidermal growth factor receptor antibody conjugated to a fluorescent probe to locate potential close or positive margins on the deep surface of the resected tumor specimen.EXPERIMENTAL DESIGN: Twelve patients with head and neck cancer scheduled for surgery received systemic administration of a tumor-specific contrast-agent (panitumumab-IRDye800). After surgical resection, the tumor specimen was imaged using a fluorescence imager. The three highest fluorescence intensity-peaks on the deep surface of the specimen were isolated and correlated to histology to determine the margin distance at these regions.RESULTS: Relative fluorescence peak-intensities identified the closest margin on the deep surface of the specimen within 2.5 minutes. The highest intensity-peak consistently (100%) detected the closest margin to the tumor. The difference in tumor margin distance between the first and second highest fluorescence intensity-peak averaged 2.1±1.4mm. The tumor-margin difference between the second and third highest peak averaged 1.6±0.6mm.CONCLUSIONS: Fluorescence intensity-peaks can identify the region on the specimen where tumor is closest to specimen's edge on the deep surface. This technique could have broad applications in obtaining adequate margins in oncological surgery.
View details for DOI 10.1158/1078-0432.CCR-19-0319
View details for PubMedID 31142505
PURPOSE: To identify the optimal dosing strategy for fluorescence-guided surgery in patients with head and neck squamous cell carcinoma, we conducted a dose-ranging study evaluating the anti-epidermal growth factor receptor (EGFR) therapeutic antibody, panitumumab, that was fluorescently labeled with the near-infrared dye IRDye800CW.PROCEDURES: Patients (n=24) received either 0.5 or 1.0mg/kg panitumumab-IRDye800CW in the weight-based dosing group or 25 or 50mg panitumumab-IRDye800CW in the fixed dosing group. Following surgery, whole primary specimens were imaged in a closed-field device and the mean fluorescence intensity (MFI) and tumor-to-background ratio (TBR) were assessed. Clinical variables, including dose, time of infusion-to-surgery, age, unlabeled dose, gender, primary tumor site, and tumor size, were analyzed to evaluate the factors affecting the fluorescence intensity in order to identify the optimal dose for intraoperative fluorescence imaging.RESULTS: A total of 24 primary tumor specimens were imaged and analyzed in this study. Although no correlations between TBR and dose of panitumumab-IRDye800CW were found, there were moderate-strong correlations between the primary tumor MFI and panitumumab-IRDye800CW dose for fixed dose (mg) (R2=0.42) and for dose/weight (mg/kg) (R2=0.54). Results indicated that the optimal MFI was at approximately 50mg for fixed dose and 0.75mg/kg for dose/weight. No significant differences were found for the primary tumor MFI and TBRs between the weight-based dosing and the fixed dosing groups. MFIs significantly increased when the infusion-to-surgery window was reduced to within 2days (vs. 3days or more, p<0.05).CONCLUSIONS: Antibody-based imaging for surgical resection is under investigation in multiple clinical trials. Our data suggests that a fixed dose of 50mg is an appropriate diagnostic dose for successful surgical fluorescence imaging.
View details for PubMedID 31054001
Prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) can visualize metastatic lesions in recurrent prostate cancer (PC). However, reliable identification of small and/or atypically localized lesions during salvage surgery procedures is challenging.To describe the technique, feasibility, and short-term outcomes of 99mTechnetium (99mTc)-based PSMA-radioguided surgery (99mTc-PSMA-RGS) for removal of recurrent PC lesions.Thirty-one consecutive patients with evidence of recurrent PC on 68Ga-PSMA N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl] ethylenediamine-N,N'-diacetic acid (68Ga-PSMA-11) PET after radical prostatectomy undergoing 99mTc-PSMA-RGS were retrospectively analyzed.Salvage surgery with intraoperative radioguidance using a gamma probe was performed after intravenous application of 99mTc-PSMA investigation and surgery (mean activity 571 MBq, mean time to surgery 19.7h).Radioactive rating (positive vs negative) of resected tissue was compared with the findings of postoperative histopathological analysis. Best prostate-specific antigen (PSA) response without additional treatment was determined after 8-16 wk postoperatively. Biochemical recurrence- and treatment-free survival was evaluated.In total, 132 tissue specimens were removed, of which 58 showed metastatic involvement on histological analysis. On a specimen basis, radioactive rating yielded a sensitivity of 83.6% (confidence interval [CI]: 70.9-91.5%), a specificity of 100%, and an accuracy of 93.0% (CI: 85.5-96.7%). With 99mTc-PSMA-RGS, all lesions visualized on preoperative 68Ga-PSMA-11 PET could be removed. Moreover, 99mTc-PSMA-RGS detected additional metastases as small as 3mm in two patients. Thirteen patients suffered from complications related to surgery (Clavien-Dindo grade 1: 12 patients; grade 3a: one patient). A PSA reduction below 0.2 ng/ml was observed in 20 patients. Thirteen patients remained biochemical recurrence free after a median follow-up of 13.8 (range: 4.6-18.3) mo. Twenty patients continued to be treatment free after a median follow-up of 12.2 (range: 5.5-18.3) mo.As a new technique for surgical guidance, 99mTc-PSMA-RGS is feasible, and has been proved to be of high value for successful intraoperative detection and removal of metastatic lesions in PC patients scheduled for salvage surgery. Its long-term impact on outcome has to be evaluated.In this report, we evaluated a novel technique to identify metastatic lesions intraoperatively in patients with recurrent prostate cancer to facilitate surgical removal. After intravenous injection of radioactive molecules that specifically bind to prostate cancer cells that show increased expression of the prostate-specific membrane antigen, we were able to detect and remove these metastatic lesions during surgery. Following salvage surgery, 41.9% of patients remained biochemical recurrence free (median follow-up of 13.8 mo) and 64.5% continued to be treatment free (median follow-up of 12.2 mo).
View details for PubMedID 29625755
PURPOSE: Near-infrared photoimmunotherapy (NIR-PIT) is a localized molecular cancer therapy combining a photosensitizer-conjugated monoclonal antibody and light energy. CD47 is an innate immune checkpoint widely expressed on bladder cancer cells but absent from luminal normal urothelium. Targeting CD47 for NIR-PIT has the potential to selectively induce cancer cell death and minimize damage to normal urothelium.EXPERIMENTAL DESIGN: The cytotoxic effect of NIR-PIT with anti-CD47-IR700 was investigated in human bladder cancer cell lines and primary human bladder cancer cells derived from fresh surgical samples. Phagocytosis assays were performed to evaluate macrophage activity after NIR-PIT. Anti-CD47-IR700 was administered to murine xenograft tumor models of human bladder cancer for in vivo molecular imaging and NIR-PIT.RESULTS: Cytotoxicity in cell lines and primary bladder cancer cells significantly increased in a light-dose dependent manner with CD47-targeted NIR-PIT. Phagocytosis of cancer cells significantly increased with NIR-PIT compared to antibody alone (p=0.0002). In vivo fluorescence intensity of anti-CD47-IR700 in tumors reached a peak 24-hour post injection and was detectable for at least 14 days. After a single round of CD47-targeted NIR-PIT, treated animals showed significantly slower tumor growth compared to controls (p<0.0001). Repeated CD47-targeted NIR-PIT treatment further slowed tumor growth (p=0.0104) and improved survival compared to controls.CONCLUSION: CD47-targeted NIR-PIT increased direct cancer cell death and phagocytosis resulting in inhibited tumor growth and improved survival in a murine xenograft model of human bladder cancer.
View details for PubMedID 30890547
Although surgical resection has been the primary treatment modality of solid tumors for decades, surgeons still rely on visual cues and palpation to delineate healthy from cancerous tissue. This may contribute to the high rate (up to 30%) of positive margins in head and neck cancer resections. Margin status in these patients is the most important prognostic factor for overall survival. In addition, second primary lesions may be present at the time of surgery. Although often unnoticed by the medical team, these lesions can have significant survival ramifications. We hypothesize that real-time fluorescence imaging can enhance intraoperative decision-making by aiding the surgeon in detecting close or positive margins and visualizing unanticipated regions of primary disease. The purpose of this study was to assess the clinical utility of real-time fluorescence imaging for intraoperative decision-making. Methods: Head and neck cancer patients (n = 14) scheduled for curative resection were enrolled in a clinical trial evaluating panitumumab-IRDye800CW for surgical guidance (NCT02415881). Open-field fluorescence imaging was performed throughout the surgical procedure. The fluorescence signal was quantified as signal-to-background ratios to characterize the fluorescence contrast of regions of interest relative to background. Results: Fluorescence imaging was able to improve surgical decision-making in three cases (21.4%); identification of a close margin (n = 1) and unanticipated regions of primary disease (n = 2). Conclusion: This study demonstrates the clinical applications of fluorescence imaging on intraoperative decision-making. This information is required for designing phase III clinical trials using this technique. Furthermore, this study is the first to demonstrate this application for intraoperative decision-making during resection of primary tumors.
View details for PubMedID 30733319
BACKGROUND: Although most patients with PDAC experience distant failure after resection, a significant portion still present with local recurrence. Intraoperative fluorescent imaging can potentially facilitate the visualization of involved peritumoral LNs and guide the locoregional extent of nodal dissection. Here, the efficacy of targeted intraoperative fluorescent imaging was examined in the detection of metastatic lymph nodes (LNs) during resection of pancreatic ductal adenocarcinoma (PDAC).METHODS: A dose-escalation prospective study was performed to assess feasibility of tumor detection within peripancreatic LNs using cetuximab-IRDye800 in PDAC patients. Fluorescent imaging of dissected LNs was analyzed exvivo macroscopically and microscopically and fluorescence was correlated with histopathology.RESULTS: A total of 144 LNs (72 in the low-dose and 72 in the high-dose cohort) were evaluated. Detection of metastatic LNs by fluorescence was better in the low-dose (50mg) cohort, where sensitivity and specificity was 100% and 78% macroscopically, and 91% and 66% microscopically. More importantly, this method was able to detect occult foci of tumor (measuring<5mm) with a sensitivity of 88% (15/17 LNs).CONCLUSION: This study provides proof of concept that intraoperative fluorescent imaging with cetuximab-IRDye800 can facilitate the detection of peripancreatic lymph nodes often containing subclinical foci of disease.
View details for PubMedID 30723062
OBJECTIVE: Surgical resection remains the primary treatment for the majority of solid tumors. Despite efforts to obtain wide margins, close or positive surgical margins (<5?mm) are found in 15-30% of head and neck cancer patients. Obtaining negative margins requires immediate, intraoperative feedback of margin status. To this end, we propose optical specimen mapping of resected tumor specimens immediately after removal.MATERIALS AND METHODS: A first-in-human pilot study was performed in patients (n?=?8) after infusion of fluorescently labeled antibody, panitumumab-IRDye800 to allow surgical mapping of the tumor specimen. Patients underwent standard of care surgical resection for head and neck squamous cell carcinoma (HNSCC). Optical specimen mapping was performed on the primary tumor specimen and correlated with pathological findings after tissue processing.RESULTS: Optical mapping of the specimen had a 95% sensitivity and 89% specificity to detect cancer within 5?mm (n?=?160) of the cut surface. To detect tumor within 2?mm of the specimen surface, the sensitivity of optical specimen mapping was 100%. The maximal observed penetration depth of panitumumab-IRDye800 through human tissue in our study was 6.3?mm.CONCLUSION: Optical specimen mapping is a highly sensitive and specific method for evaluation of margins within <5?mm of the tumor mass in HNSCC specimens. This technology has potentially broad applications for ensuring adequate tumor resection and negative margins in head and neck cancers.
View details for PubMedID 30616798
In head and neck cancer, surgical resection using primarily visual and tactile feedback is considered gold standard for solid tumors. Due to high numbers of tumor-involved surgical margins which are directly correlated to poor clinical outcome, intraoperative optical imaging trials have rapidly proliferated over the past five years. However, few studies report on intraoperative in situ imaging data that could support surgical resection. To demonstrate the clinical application of in situ surgical imaging, we report on the imaging data that is directly (i.e. in real-time) available to the surgeon.Fluorescence intensities and tumor-to-background ratios (TBRs) were determined from the intraoperative imaging data - the view as seen by the surgeon during tumor resection - of 20 patients and correlated to patient and tumor characteristics including age, sex, tumor site, tumor size, histological differentiation and EGFR expression. Furthermore, different lighting conditions in regard to surgical workflow were evaluated.Under these circumstances, intraoperative TBRs of the primary tumors averaged 2.2±0.4 (range 1.5-2.9). Age, sex, tumor site, and tumor size did not have a significant effect on open-field intraoperative molecular imaging of the primary tumors (p>0.05). In addition, variation in EGFR expression levels or the presence of ambient light did not seem to alter TBRs.We present the results of successful in situ intraoperative imaging of primary tumors alongside the optimal conditions with respect to both molecular image acquisition and surgical workflow. This study illuminates the potentials of open-field molecular imaging to assist the surgeon in achieving successful cancer removal.
View details for DOI 10.1016/j.jamcollsurg.2019.09.007
View details for PubMedID 31568855
For many solid tumors, surgical resection remains the gold standard and tumor-involved margins are associated with poor clinical outcomes. Near-infrared (NIR) fluorescence imaging using molecular agents has shown promise for in situ imaging during resection. However, for cancers with difficult imaging conditions, surgical value may lie in tumor-mapping of surgical specimens. We thus evaluated a novel approach for real-time, intraoperative tumor margin assessment. 21 adult patients with biopsy-confirmed squamous cell carcinoma arising from the head and neck (HNSCC) scheduled for standard-of-care surgery were enrolled. Cohort 1 (n=3) received panitumumab-IRDye800CW at an intravenous microdose of 0.06 mg/kg, cohort 2A (n=5) received 0.5mg/kg, cohort 2B (n=7) received 1mg/kg, and cohort 3 (n=6) received 50 mg. Patients were followed 30 days post-infusion and adverse events were recorded. Imaging was performed using several closed- and wide-field devices. Fluorescence was histologically correlated to determine sensitivity and specificity. In situ imaging demonstrated tumor-to-background ratio (TBR) of 2-3, compared to ex vivo specimen imaging TBR of 5-6. We obtained clear differentiation between tumor and normal tissue, with a three-fold signal difference between positive and negative specimens (p<0.05). We achieved high correlation of fluorescence intensity with tumor location with sensitivities and specificities >89%; fluorescence predicted distance of tumor tissue to the cut surface of the specimen. This novel method of detecting tumor-involved margins in surgical specimens using a cancer-specific agent provides highly sensitive and specific, real-time, intraoperative surgical navigation in resections with complex anatomy which are otherwise less amenable to image guidance.
View details for PubMedID 29967260
Intraoperative imaging (IOI) is performed to guide delineation and localization of regions of surgical interest. While oncological surgical planning predominantly utilizes x-ray computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US), intraoperative guidance mainly remains on surgeon interpretation and pathology for confirmation. Over the past decades however, intraoperative guidance has evolved significantly with the emergence of several novel imaging technologies, including fluorescence-, Raman, photoacoustic-, and radio-guided approaches. These modalities have demonstrated the potential to further optimize precision in surgical resection and improve clinical outcomes for patients. Not only can these technologies enhance our understanding of the disease, they can also yield large imaging datasets intraoperatively that can be analyzed by deep learning approaches for more rapid and accurate pathological diagnosis. Unfortunately, many of these novel technologies are still under preclinical or early clinical evaluation. Organizations like the Intra-Operative Imaging Study Group of the European Society for Molecular Imaging (ESMI) support interdisciplinary interactions with the aim to improve technical capabilities in the field, an approach that can succeed only if scientists, engineers, and physicians work closely together with industry and regulatory bodies to resolve roadblocks to clinical translation. In this review, we provide an overview of a variety of novel IOI technologies, discuss their challenges, and present future perspectives on the enormous potential of IOI for oncological surgical navigation.
View details for PubMedID 29916118
Purpose: To demonstrate the safety and feasibility of leveraging therapeutic antibodies for surgical imaging. Procedures: We conducted two phase I trials for anti-epidermal growth factor receptor antibodies cetuximab-IRDye800CW (n=12) and panitumumab-IRDye800CW (n=15). Adults with biopsy-confirmed head and neck squamous cell carcinoma scheduled for standard-of-care surgery were eligible. For cetuximab-IRDye800CW, cohort 1 was intravenously infused with 2.5 mg/m2, cohort 2 received 25 mg/m2, and cohort 3 received 62.5 mg/m2. For panitumumab-IRDye800CW, cohorts received 0.06 mg/kg, 0.5 mg/kg, and 1 mg/kg, respectively. Electrocardiograms and blood samples were obtained, and patients were followed for 30 days post-study drug infusion. Results: Both fluorescently labeled antibodies had similar pharmacodynamic properties and minimal toxicities. Two infusion reactions occurred with cetuximab and none with panitumumab. There were no grade 2 or higher toxicities attributable to cetuximab-IRDye800CW or panitumumab-IRDye800CW; fifteen grade 1 adverse events occurred with cetuximab-IRDye800CW, and one grade 1 occurred with panitumumab-IRDye800CW. There were no significant differences in QTc prolongation between the two trials (p=0.8). Conclusions: Panitumumab-IRDye800CW and cetuximab-IRDye800CW have toxicity and pharmacodynamic profiles that match the parent compound, suggesting that other therapeutic antibodies may be repurposed as imaging agents with limited preclinical toxicology data.
View details for PubMedID 29721094
Intraoperative fluorescence imaging is particularly well-suited for surgical applications due to its inherently high sensitivity, resolution, and ability to provide images in real-time. To date, the intraoperative observation of fluorescence has largely been subjective. With the need to show objective evidence in order to demonstrate the benefit of this technique, quantitative data needs to be provided to overseeing regulatory bodies. Standardization of fluorescence imaging protocols would improve reproducibility and minimize inter- and intra-institution variance. This would allow studies to be conducted using the same injection techniques, imaging times, reconstruction methods, and analyses. Here, we provide recommendations for standardized methodologies with the goal of setting a minimum requirement for reporting fluorescence-guided surgery results based on both qualitative and (semi-) quantitative data collection. Clinical trials using fluorescence-guided surgery should present results of three critical elements; 1) intra-operative imaging, 2) specimen mapping and pathology correlation, and 3) target validation. Qualitative analyses should consist of a bright field image, black-and-white fluorescence image, pseudo-colored fluorescence overlay image, and/or heat-map whereby fluorescence signal intensity differences are displayed on a color spectrum. Quantitative analyses should include 1) intraoperative data (consisting of images or video, raw numeric values and ratios); 2) specimen mapping, for correlation of fluorescence with the presence of disease (performed using fresh tissue); and 3) target validation (designed to determine fluorescence intensity relative to receptor density of a specific area). Including the aforementioned methods of both qualitative and quantitative analyses will ensure that trial results are comparable and could be collated in future studies to expedite FDA approval.
View details for PubMedID 30555550
View details for PubMedCentralID PMC6276089
For radical resection of squamous cell carcinoma of the oral cavity, a tumor free margin of at least 5 mm is required. Unfortunately, establishing in-depth margins is a surgical conundrum. Knowing the hybrid sentinel node (SN) tracer indocyanine green (ICG)-99mTc-nanocolloid generates temporary tattoo-like markings at the site of administration, we studied the ability of applying this tracer for tumor-margin demarcation combined with SN biopsy. Methods: Nineteen patients with clinical T1-2 oral tongue tumors received the traditional superficial three-four deposits of ICG-99mTc-nanocolloid (0.1mL each) and in twelve patients additional deposits were placed in-depth using ultrasound guidance (total six; 0.07mL each). SN mapping was performed using lymphoscintigraphy and SPECT/CT. Prior to, and directly after tumor excision, fluorescence imaging was performed to monitor the tracer deposits in the patient (fluorescent deposits were not used to guide the surgical excision). At pathology primary tumor samples were studied in detail. Results: The number of tracer depositions did not induce a significant difference in the number of SNs visualized (P = 0.836). Reproducible and in-depth tracer deposition proved to be challenging. The fluorescent nature of ICG-99mTc-nanocolloid supported in vivo and ex vivo identification of the tracer deposits surrounding the tumor. Pathological examination indicated that in 66.7% (8/12) all fluorescence was observed within the resection-margins. Conclusion: This study indicates tumor margin-demarcation combined with SN identification has potential, but needs to overcome some practical challenges in order to mature as surgical guidance concept. Future studies need to define if the technology can improve the radical nature of the resections.
View details for PubMedID 30504140
Maximizing extent of surgical resection with the least morbidity remains critical for survival in glioblastoma patients, and we hypothesize that it can be improved by enhancements in intraoperative tumor detection. In a clinical study, we determined if therapeutic antibodies could be repurposed for intraoperative imaging during resection.Fluorescently labeled cetuximab-IRDye800 was systemically administered to three patients 2 days prior to surgery. Near-infrared fluorescence imaging of tumor and histologically negative peri-tumoral tissue was performed intraoperatively and ex vivo. Fluorescence was measured as mean fluorescence intensity (MFI), and tumor-to-background ratios (TBRs) were calculated by comparing MFIs of tumor and histologically uninvolved tissue.The mean TBR was significantly higher in tumor tissue of contrast-enhancing (CE) tumors on preoperative imaging (4.0?±?0.5) compared to non-CE tumors (1.2?±?0.3; p?=?0.02). The TBR was higher at a 100 mg dose than at 50 mg (4.3 vs. 3.6). The smallest detectable tumor volume in a closed-field setting was 70 mg with 50 mg of dye and 10 mg with 100 mg. On sections of paraffin embedded tissues, fluorescence positively correlated with histological evidence of tumor. Sensitivity and specificity of tumor fluorescence for viable tumor detection was calculated and fluorescence was found to be highly sensitive (73.0% for 50 mg dose, 98.2% for 100 mg dose) and specific (66.3% for 50 mg dose, 69.8% for 100 mg dose) for viable tumor tissue in CE tumors while normal peri-tumoral tissue showed minimal fluorescence.This first-in-human study demonstrates the feasibility and safety of antibody based imaging for CE glioblastomas.
View details for PubMedID 29623552
To explore the evidence and knowledge gaps in sentinel node biopsy (SNB) in prostate cancer through a consensus panel of experts.A two-round Delphi survey among experts was followed by a consensus panel meeting of 16 experts in February 2016. Agreement voting was performed using the research and development project/University of California, Los Angeles Appropriateness Methodology on 150 statements in nine domains. The disagreement index based on the interpercentile range, adjusted for symmetry score, was used to assess consensus and non-consensus among panel members.Consensus was obtained on 91 of 150 statements (61%). The main outcomes were: (1) the results from an extended lymph node dissection (eLND) are still considered the 'gold standard', and sentinel node (SN) detection should be combined with eLND, at least in patients with intermediate- and high-risk prostate cancer; (2) the role of SN detection in low-risk prostate cancer is unclear; and (3) future studies should contain oncological endpoints as number of positive nodes outside the eLND template, false-negative and false-positive SN procedures, and recurrence-free survival. A high rate of consensus was obtained regarding outcome measures of future clinical trials on SNB (89%). Consensus on tracer technology was only obtained in 47% of statements, reflecting a need for further research and standardization in this area. The low-level evidence in the available literature and the composition of mainly SNB users in the panel constitute the major limitations of the study.Consensus on a majority of elementary statements on SN detection in prostate cancer was obtained.; therefore, the results from this consensus report will provide a basis for the design of further studies in the field. A group of experts identified evidence and knowledge gaps on SN detection in prostate cancer and its application in daily practice. Information from the consensus statements can be used to direct further studies.
View details for DOI 10.1111/bju.13810
View details for PubMedID 28188689
Extended pelvic lymph node dissection (ePLND) is the gold standard for detecting lymph node (LN) metastases in prostate cancer (PCa). The benefit of sentinel node biopsy (SNB), which is the first draining LN as assessed by imaging of locally injected tracers, remains controversial.To assess the diagnostic accuracy of SNB in PCa.A systematic literature search of Medline, Embase, and the Cochrane Library (1999-2016) was undertaken using PRISMA guidelines. All studies of SNB in men with PCa using PLND as reference standard were included. The primary outcomes were the nondiagnostic rate (NDR), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and false positive (FP) and false negative (FN) rates. Relevant sensitivity analyses based on SN definitions, ePLND as reference standard, and disease risk were undertaken, including a risk of bias (RoB) assessment.Of 373 articles identified, 21 studies recruiting a total of 2509 patients were eligible for inclusion. Median cumulative percentage (interquartile range) results were 4.1% (1.5-10.7%) for NDR, 95.2% (81.8-100%) for sensitivity, 100% (95.0-100%) for specificity, 100% (87.0-100%) for PPV, 98.0% (94.3-100%) for NPV, 0% (0-5.0%) for the FP rate, and 4.8% (0-18.2%) for the FN rate. The findings did not change significantly on sensitivity analyses. Most studies (17/22) had low RoB for index test and reference standard domains.SNB appears to have diagnostic accuracy comparable to ePLND, with high sensitivity, specificity, PPV and NPV, and a low FN rate. With a low FP rate (rate of detecting positive nodes outside the ePLND template), SNB may not have any additional diagnostic value over and above ePLND, although SNB appears to increase nodal yield by increasing the number of affected nodes when combined with ePLND. Thus, in high-risk disease it may be prudent to combine ePLND with SNB.This literature review showed a high diagnostic accuracy for sentinel node biopsy in detecting positive lymph nodes in prostate cancer, but further studies are needed to explore the effect of sentinel node biopsy on complications and oncologic outcome.
View details for PubMedID 27639533
Intraoperative sentinel node (SN) identification in patients with head-and-neck malignancies can be challenging due to unexpected drainage patterns and anatomical complexity. Here, intraoperative navigation-based guidance technologies may provide outcome. In this study, gamma camera-based freehandSPECT was evaluated in combination with the hybrid tracer ICG-99mTc-nanocolloid.Eight patients with melanoma located in the head-and-neck area were included. Indocyanine green (ICG)-99mTc-nanocolloid was injected preoperatively, whereafter lymphoscintigraphy and SPECT/CT imaging were performed in order to define the location of the SN(s). FreehandSPECT scans were generated in the operation room using a portable gamma camera. For lesion localization during surgery, freehandSPECT scans were projected in an augmented reality video-view that was used to spatially position a gamma-ray detection probe. Intraoperative fluorescence imaging was used to confirm the accuracy of the navigation-based approach and identify the exact location of the SNs.Preoperatively, 15 SNs were identified, of which 14 were identified using freehandSPECT. Navigation towards these nodes using the freehandSPECT approach was successful in 13 nodes. Fluorescence imaging provided optical confirmation of the navigation accuracy in all patients. In addition, fluorescence imaging allowed for the identification of (clustered) SNs that could not be identified based on navigation alone.The use of gamma camera-based freehandSPECT aids intraoperative lesion identification and, with that, supports the transition from pre- to intraoperative imaging via augmented reality display and directional guidance.
View details for PubMedID 28819936
View details for PubMedCentralID PMC5560283
To determine the accuracy of automatic and manual co-registration methods for image fusion of three-dimensional computed tomography (CT) with real-time ultrasonography (US) for image-guided liver interventions.CT images of a skills phantom with liver lesions were acquired and co-registered to US using GE Logiq E9 navigation software. Manual co-registration was compared to automatic and semiautomatic co-registration using an active tracker. Also, manual point registration was compared to plane registration with and without an additional translation point. Finally, comparison was made between manual and automatic selection of reference points. In each experiment, accuracy of the co-registration method was determined by measurement of the residual displacement in phantom lesions by two independent observers.Mean displacements for a superficial and deep liver lesion were comparable after manual and semiautomatic co-registration: 2.4 and 2.0 mm versus 2.0 and 2.5 mm, respectively. Both methods were significantly better than automatic co-registration: 5.9 and 5.2 mm residual displacement (p < 0.001; p < 0.01). The accuracy of manual point registration was higher than that of plane registration, the latter being heavily dependent on accurate matching of axial CT and US images by the operator. Automatic reference point selection resulted in significantly lower registration accuracy compared to manual point selection despite lower root-mean-square deviation (RMSD) values.The accuracy of manual and semiautomatic co-registration is better than that of automatic co-registration. For manual co-registration using a plane, choosing the correct plane orientation is an essential first step in the registration process. Automatic reference point selection based on RMSD values is error-prone.
View details for PubMedID 28204959
The clinically applied hybrid tracer indocyanine green-(99m)Tc-nanocolloid enables combined radio- and fluorescence image guidance during sentinel node (SN) biopsy procedures. To provide optimal surgical guidance, this tracer requires the presence of both ?- and fluorescence modalities in the operating room. We reasoned that the combination or integration of these modalities could further evolve the hybrid surgical guidance concept. To study this potential, we clinically applied 2 setups that included the combination of ?-detection modalities and an open surgery fluorescence camera. Methods: To attach the fluorescence camera (VITOM) to either a ?-ray detection probe (GP; VITOM-GP) or a portable ?-camera (GC; Vitom GC), clip-on brackets were designed and printed in 3-dimensional sterilizable RC31. Both combined modalities were evaluated in, respectively, 5 and 6 patients with penile cancer during an SN biopsy procedure using indocyanine green-(99m)Tc-nanocolloid. Intraoperatively, radio- and fluorescence-guided SN detection rates were scored at working distances of 0, 10, 20, and 30 cm for both combinations. Results: Using the VITOM-GP combination, we evaluated 9 SNs. ?-tracing rates were shown to be 100%, 88.9%, 55.6%, and 55.6% at a respective working distance of 0, 10, 20, and 30 cm. Detection rates for the fluorescence imaging-based detection were found to be 100%, 77.8%, and 77.8%, at respective working distances of 10, 20, and 30 cm. When the VITOM-GC setup was used, all 10 intraoperatively evaluated SNs could be visualized with the ?-camera independent of the working distance. Fluorescence detection rates were 90%, 80%, and 80% at 10-, 20-, and 30-cm working distances. The integrated detection modalities were shown to work synergistically; overall the, GC was most valuable for rough localization (10- to 30-cm range) of the SNs, the GP for providing convenient real-time acoustic feedback, whereas fluorescence guidance allowed detailed real-time SN visualization. Conclusion: Our findings suggest that full integration of a fluorescence camera with ?-detector (GP or GC) can be of value when a hybrid, radioactive and fluorescent tracer is used.
View details for PubMedID 27688478
With the introduction of the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid, a direct relation between preoperative imaging and intraoperative fluorescence guidance was established. However, fluorescence guidance remains limited by its superficial nature. This study evaluated the feasibility of a nuclear medicine-based navigation concept that allowed intraoperative positioning of a fluorescence camera (FC) in the vicinity of preoperatively defined ICG-(99m)Tc-nanocolloid containing sentinel nodes (SNs).Five patients with penile cancer scheduled for SN biopsy were injected with ICG-(99m)Tc-nanocolloid followed by preoperative SPECT/CT imaging. The navigation device was used to provide a real-time augmented reality overlay of the SPECT/CT images and video output of the FC. This overlay was then used for FC navigation.SPECT/CT identified 13 SNs in 9 groins. FC navigation was successful for all 12 intraoperatively evaluated SNs (average error, 8.8 mm; range, 0-20 mm).This study reveals the potential benefits of FC navigation during open surgery procedures.
View details for DOI 10.2967/jnumed.115.171645
View details for Web of Science ID 000384961900034
View details for PubMedID 27230927
Fluorescence guidance is an upcoming methodology to improve surgical accuracy. Challenging herein is the identification of the minimum dose at which the tracer can be detected with a clinical-grade fluorescence camera. Using a hybrid tracer such as indocyanine green (ICG)-(99m)Tc-nanocolloid, it has become possible to determine the accumulation of tracer and correlate this to intraoperative fluorescence-based identification rates. In the current study, we determined the lower detection limit of tracer at which intraoperative fluorescence guidance was still feasible.Size exclusion chromatography (SEC) provided a laboratory set-up to analyze the chemical content and to simulate the migratory behavior of ICG-nanocolloid in tissue. Tracer accumulation and intraoperative fluorescence detection findings were derived from a retrospective analysis of 20 head-and-neck melanoma patients, 40 penile and 20 prostate cancer patients scheduled for sentinel node (SN) biopsy using ICG-(99m)Tc-nanocolloid. In these patients, following tracer injection, single photon emission computed tomography fused with computed tomography (SPECT/CT) was used to identify the SN(s). The percentage injected dose (% ID), the amount of ICG (in nmol), and the concentration of ICG in the SNs (in ?M) was assessed for SNs detected on SPECT/CT and correlated with the intraoperative fluorescence imaging findings.SEC determined that in the hybrid tracer formulation, 41 % (standard deviation: 12 %) of ICG was present in nanocolloid-bound form. In the SNs detected using fluorescence guidance a median of 0.88 % ID was present, compared to a median of 0.25 % ID in the non-fluorescent SNs (p-value?0.001). The % ID values could be correlated to the amount ICG in a SN (range: 0.003-10.8 nmol) and the concentration of ICG in a SN (range: 0.006-64.6 ?M).The ability to provide intraoperative fluorescence guidance is dependent on the amount and concentration of the fluorescent dye accumulated in the lesion(s) of interest. Our findings indicate that intraoperative fluorescence detection with ICG is possible above a ?M concentration.
View details for DOI 10.1007/s00259-016-3372-y
View details for Web of Science ID 000380700100012
View details for PubMedID 27020580
View details for PubMedCentralID PMC4969335
To assess if combined fluorescence- and radio-guided occult lesion localization (hybrid ROLL) is feasible in patients scheduled for surgical resection of non-palpable (18)F-FDG-avid lesions on PET/CT.Four patients with (18)F-FDG-avid lesions on follow-up PET/CT that were not palpable during physical examination but were suspected to harbor metastasis were enrolled. Guided by ultrasound, the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was injected centrally in the target lesion. SPECT/CT imaging was used to confirm tracer deposition. Intraoperatively, lesions were localized using a hand-held gamma ray detection probe, a portable gamma camera, and a fluorescence camera. After excision, the gamma camera was used to check the wound bed for residual activity.A total of six (18)F-FDG-avid lymph nodes were identified and scheduled for hybrid ROLL. Comparison of the PET/CT images with the acquired SPECT/CT after hybrid tracer injection confirmed accurate tracer deposition. No side effects were observed. Combined radio- and fluorescence-guidance enabled localization and excision of the target lesion in all patients. Five of the six excised lesions proved tumor-positive at histopathology.The hybrid ROLL approach appears to be feasible and can facilitate the intraoperative localization and excision of non-palpable lesions suspected to harbor tumor metastases. In addition to the initial radioguided detection, the fluorescence component of the hybrid tracer enables high-resolution intraoperative visualization of the target lesion. The procedure needs further evaluation in a larger cohort and wider range of malignancies to substantiate these preliminary findings.
View details for DOI 10.1016/j.remn.2016.04.001
View details for PubMedID 27174865
Even when guided by SPECT/CT planning of nodal resection in the head-and-neck area is challenging due to the many critical anatomical structures present within the surgical field. In this study the potential of a (SPECT/)MRI-based surgical planning method was explored. Hereby MRI increases the identification of SNs within clustered lymph nodes (LNs) and vital structures located adjacent to the SN (such as cranial nerve branches).SPECT/CT and pathology reports from 100 head-and-neck melanoma and 40 oral cavity cancer patients were retrospectively assessed for SN locations in levels I-V and degree of nodal clustering. A diffusion-weighted-preparation magnetic resonance neurography (MRN) sequence was used in eight healthy volunteers to detect LNs and peripheral nerves.In 15% of patients clustered nodes were retrospectively shown to be present at the location where the SN was identified on SPECT/CT (level IIA: 37.2%, level IIB: 21.6% and level III: 15.5%). With MRN, improved LN delineation enabled discrimination of individual LNs within a cluster. Uniquely, this MRI technology also provided insight in LN distribution (23.2±4 LNs per subject) and size (range 21-372mm(3)), and enabled non-invasive assessment of anatomical variances in the location of the LNs and facial nerves.Diffusion-weighted-preparation MRN enabled improved delineation of LNs and their surrounding delicate anatomical structures in the areas that most often harbor SNs in the head-and-neck. Based on our findings a combined SPECT/MRI approach is envisioned for future surgical planning of complex SN resections in this region.
View details for DOI 10.1016/j.oraloncology.2016.06.015
View details for PubMedID 27531872
In open surgery procedures, after temporarily dimming the lights in the operation theatre, the Photo Dynamic Eye (PDE) fluorescence camera has, amongst others, been used for fluorescence-guided sentinel node (SN) biopsy procedures. To improve the clinical utility and logistics of fluorescence-guided surgery, we developed and evaluated a prototype modified PDE (m-PDE) fluorescence camera system.The m-PDE works under ambient light conditions and includes a white light mode and a pseudo-green-colored fluorescence mode (including a gray-scaled anatomical background). Twenty-seven patients scheduled for SN biopsy for (head and neck) melanoma (n = 16), oral cavity (n = 6), or penile (n = 5) cancer were included. The number and location of SNs were determined following an indocyanine green-(99m)Tc-nanocolloid injection and preoperative imaging. Intraoperatively, fluorescence guidance was used to visualize the SNs. The m-PDE and conventional PDE were compared head-to-head in a phantom study, and in seven patients. In the remaining 20 patients, only the m-PDE was evaluated.Phantom study: The m-PDE was superior over the conventional PDE, with a detection sensitivity of 1.20 × 10(-11) M (vs. 3.08 × 10(-9) M) ICG in human serum albumin. In the head-to-head clinical comparison (n = 7), the m-PDE was also superior: (i) SN visualization: 100 versus 81.4 %; (ii) transcutaneous SN visualization: 40.7 versus 22.2 %; and (iii) lymphatic duct visualization: 7.4 versus 0 %. Findings were further underlined in the 20 additionally included patients.The m-PDE enhanced fluorescence imaging properties compared with its predecessor, and provides a next step towards routine integration of real-time fluorescence guidance in open surgery.
View details for DOI 10.1245/s10434-016-5186-3
View details for Web of Science ID 000379189900033
View details for PubMedID 27020586
View details for PubMedCentralID PMC4927603
To explore the feasibility of an intraoperative navigation technology based on preoperatively acquired single photon emission computed tomography combined with computed tomography (SPECT/CT) images during sentinel node (SN) biopsy in patients with melanoma or Merkel cell carcinoma.Patients with a melanoma (n=4) or Merkel cell carcinoma (n=1) of a lower extremity scheduled for wide re-excision of the primary lesion site and SN biopsy were studied. Following a Tc-nanocolloid injection and lymphoscintigraphy, SPECT/CT images were acquired with a reference target (ReTp) fixed on the leg or the iliac spine. Intraoperatively, a sterile ReTp was placed at the same site to enable SPECT/CT-based mixed-reality navigation of a gamma ray detection probe also containing a reference target (ReTgp).The accuracy of the navigation procedure was determined in the coronal plane (x, y-axis) by measuring the discrepancy between standard gamma probe-based SN localization and mixed-reality-based navigation to the SN. To determine the depth accuracy (z-axis), the depth estimation provided by the navigation system was compared to the skin surface-to-node distance measured in the computed tomography component of the SPECT/CT images.In four of five patients, it was possible to navigate towards the preoperatively defined SN. The average navigational error was 8.0?mm in the sagittal direction and 8.5?mm in the coronal direction. Intraoperative sterile ReTp positioning and tissue movement during surgery exerted a distinct influence on the accuracy of navigation.Intraoperative navigation during melanoma or Merkel cell carcinoma surgery is feasible and can provide the surgeon with an interactive 3D roadmap towards the SN or SNs in the groin. However, further technical optimization of the modality is required before this technology can become routine practice.
View details for DOI 10.1097/MNM.0000000000000524
View details for Web of Science ID 000380110500005
View details for PubMedID 27076206
Radical prostatectomy and complementary extended pelvic lymph node dissection (ePLND) of sentinel lymph nodes (SNs) and non-sentinel lymph nodes (LNs) at risk of containing metastases are increasingly being performed using high-tech robot-assisted approaches. Although this technological evolution has clear advantages, the physical nature of robotic systems limits the integrated use of routine radioguided surgery technologies. Hence, engineering effort in robotics are focused on the integration of fluorescence guidance technologies. Using the hybrid SN tracer indocyanine green-(99m)Tc-nanocolloid (radioactive and fluorescent), for the first time in combination with a robot-integrated laparoscope, we investigated whether the robot-assisted approach affects the accuracy of fluorescence detection of SNs identified preoperatively using nuclear medicine.The study included 55 patients (Briganti nomogram-based risk >5 % on LN metastases) scheduled for robot-assisted radical prostatectomy, SN biopsy and ePLND. Following indocyanine green-(99m)Tc-nanocolloid injection, preoperative nuclear imaging (lymphoscintigraphy and SPECT/CT) was used to locate the SN(s). The fluorescence laparoscope was used intraoperatively to identify the SN(s) with standard fluorescence settings (in 50 patients) and with customized settings (in 5 patients). The number and location of the SNs, the radioactive, fluorescence (both in vivo and ex vivo) and tumour status of the resected SNs/LNs, and postoperative complications were recorded and analysed.Combined, preoperative lymphoscintigraphy and SPECT/CT imaging identified 212 SNs (median 4 per patient). Intraoperative fluorescence imaging using standard fluorescence settings visualized 80.4 % (148/184 SNs; 50 patients; ex vivo 97.8 %). This increased to 85.7 % (12/14 SNs; 5 patients; ex vivo 100 %) with customized fluorescence settings. SPECT/CT images provided guidance towards the residual SNs. Ex vivo all removed SNs were radioactive. SNs were tumour-positive in 25.4 % of patients (14/55; false-negative rate 7 %, 1/14 patients). In ten patients, the SN was the only tumour-positive LN. Surgical complications were minimal.Directly linking 3D preoperative nuclear imaging information on SNs to a robot-integrated fluorescence laparoscope improved the surgeon's use of the technology and did not influence the sensitivity or morbidity of the procedure. To our surprise, however, the detection rates with the current fluorescence camera did not improve.
View details for DOI 10.1007/s00259-015-3292-2
View details for Web of Science ID 000376246200010
View details for PubMedID 26768422
View details for PubMedCentralID PMC4865539
Quantitative assessment of affinity and kinetics is a critical component in the development of (receptor-targeted) radiotracers. For fluorescent tracers, such an assessment is currently not yet applied, while (small) changes in chemical composition of the fluorescent component might have substantial influence on the overall properties of a fluorescent tracer. Hybrid imaging labels that contain both a radiolabel and a fluorescent dye can be used to evaluate both the affinity (fluorescent label) and the in vivo distribution (radiolabel) of a targeted tracer. We present a hybrid label oriented and matrix-based scoring approach that enabled quantitative assessment of the influence of (overall) charge and lipophilicity of the fluorescent label on the (in vivo) characteristics of ?v?3-integrin targeted tracers. Systematic chemical alterations in the fluorescent dye were shown to result in a clear difference in the in vivo distribution of the different hybrid tracers. The applied evaluation technique resulted in an optimized targeted tracer for ?v?3-integrin, which combined the highest T/M ratio with the lowest uptake in other organs. Obviously this selection concept would also be applicable during the development of other (receptor-targeted) imaging tracers.
View details for DOI 10.1021/acs.bioconjchem.6b00093
View details for Web of Science ID 000376331700011
View details for PubMedID 27074375
In this paper we present the usage of a drop-in gamma probe for intra-operative Single-Photon Emission Computed Tomography (SPECT) imaging in the scope of minimally invasive robot-assisted interventions. The probe is designed to be inserted and reside inside the abdominal cavity during the intervention. It is grasped during the procedure using a robotic laparoscopic gripper enabling full six degrees of freedom handling by the surgeon. We demonstrate the first deployment of the tracked probe for intra-operative in-patient robotic SPECT enabling augmented-reality image guidance. The hybrid mechanical- and image-based in-patient probe tracking is shown to have an accuracy of 0.2 mm. The overall system performance is evaluated and tested with a phantom for gynecological sentinel lymph node interventions and compared to ground-truth data yielding a mean reconstruction accuracy of 0.67 mm.
View details for DOI 10.1109/TMI.2015.2498125
View details for Web of Science ID 000372369700011
View details for PubMedID 26561283
During (robot-assisted) sentinel node (SN) biopsy procedures, intraoperative fluorescence imaging can be used to enhance radioguided SN excision. For this combined pre- and intraoperative SN identification was realized using the hybrid SN tracer, indocyanine green-(99m)Tc-nanocolloid. Combining this dedicated SN tracer with a lymphangiographic tracer such as fluorescein may further enhance the accuracy of SN biopsy.Clinical evaluation of a multispectral fluorescence guided surgery approach using the dedicated SN tracer ICG-(99m)Tc-nanocolloid, the lymphangiographic tracer fluorescein, and a commercially available fluorescence laparoscope.Pilot study in ten patients with prostate cancer. Following ICG-(99m)Tc-nanocolloid administration and preoperative lymphoscintigraphy and single-photon emission computed tomograpy imaging, the number and location of SNs were determined. Fluorescein was injected intraprostatically immediately after the patient was anesthetized. A multispectral fluorescence laparoscope was used intraoperatively to identify both fluorescent signatures.Multispectral fluorescence imaging during robot-assisted radical prostatectomy with extended pelvic lymph node dissection and SN biopsy.(1) Number and location of preoperatively identified SNs. (2) Number and location of SNs intraoperatively identified via ICG-(99m)Tc-nanocolloid imaging. (3) Rate of intraoperative lymphatic duct identification via fluorescein imaging. (4) Tumor status of excised (sentinel) lymph node(s). (5) Postoperative complications and follow-up.Near-infrared fluorescence imaging of ICG-(99m)Tc-nanocolloid visualized 85.3% of the SNs. In 8/10 patients, fluorescein imaging allowed bright and accurate identification of lymphatic ducts, although higher background staining and tracer washout were observed. The main limitation is the small patient population.Our findings indicate that a lymphangiographic tracer can provide additional information during SN biopsy based on ICG-(99m)Tc-nanocolloid. The study suggests that multispectral fluorescence image-guided surgery is clinically feasible.We evaluated the concept of surgical fluorescence guidance using differently colored dyes that visualize complementary features. In the future this concept may provide better guidance towards diseased tissue while sparing healthy tissue, and could thus improve functional and oncologic outcomes.
View details for PubMedID 27345689
In complex (robot-assisted) laparoscopic radioguided surgery procedures, or when low activity lesions are located nearby a high activity background, the limited maneuverability of a laparoscopic gamma probe (LGP; 4 degrees of freedom (DOF)) may hinder lesion identification. We investigated a drop-in gamma probe (DIGP) technology to be inserted via a trocar, after which the laparoscopic surgical tool at hand can pick it up and maneuver it. Phantom experiments showed that distinguishing a low objective from a high background source (1:100 ratio) was only possible with the detector faced >90° from the high background source. Signal-low-objective-to-background ratios of 3.77, 2.01 and 1.84 were found for detector angles of 90°, 135° and 180°, respectively, whereas detector angles of 0° and 45° were unable to distinguish the sources. This underlines the critical role probe positioning plays. We then focused on engineering of the gripping part for optimal DIGP pick-up with a conventional laparoscopic forceps (4 DOF) or a robotic forceps (6 DOF). DIGPs with 0°, 45°, 90°, and 135° -grip orientations were designed, and their maneuverability- and scanning direction were evaluated and compared to a conventional LGP. The maneuverability- and scanning direction of the DIGP was found highest when using the robotic forceps, with the largest effective scanning direction range obtained with the 90° -grip design (0-180° versus 0-111°, 0-140°, and 37-180° for 0°, 45° and 135° -grip designs, respectively). For the laparoscopic forceps, the scan direction directly translated from the angle of the grip design with the advantage that the 135° -gripped DIGP could be faced backwards (not possible with the conventional LGP). In the ex vivo clinical setup, the surgeon rated DIGP pick-up most convenient for the 45°-grip design. Concluding, the DIGP technology was successfully introduced. Optimization of the grip design and grasping angle of the DIGP increased its utility for (robot-assisted) laparoscopic gamma tracing.
View details for PubMedID 27069762
The clinical introduction of the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid, composed of a radioactive and a near-infrared (NIR) fluorescence component, has created the need for surgical (imaging) modalities that allow for simultaneous detection of both signals. This study describes the first-in-human use of a prototype opto-nuclear probe during sentinel node (SN) biopsy using ICG-(99m)Tc-nanocolloid.To allow for fluorescence tracing, a derivative of the conventional gamma probe technology was generated in which two optical fibers were integrated to allow for excitation (785 nm) and emission signal collection (> 810 nm). The ability of this opto-nuclear probe to detect the fluorescence signal of the hybrid tracer ICG-(99m)Tc-nanocolloid was firstly determined ex vivo in (non)SNs samples obtained from 41 patients who underwent hybrid tracer-based SN biopsy in the head and neck or urogenital area. In an in vivo proof-of-concept study in nine of these 41 patients, SNs were localized using combined gamma and fluorescence tracing with the opto-nuclear probe. Fluorescence tracing was performed in a similar manner as gamma tracing and under ambient light conditions.Ex vivo, the gamma tracing option of the opto-nuclear probe correctly identified the SN in all 150 evaluated (non)SN samples. Ex vivo fluorescence tracing in the low-sensitivity mode correctly identified 71.7% of the samples. This increased to 98.9% when fluorescence tracing was performed in the high-sensitivity mode. In vivo fluorescence tracing (high-sensitivity mode) accurately identified the SNs in all nine patients (20 SNs evaluated; 100%).This study demonstrates the first-in-human evaluation of a hybrid modality capable of detecting both gamma and fluorescence signals during a surgical procedure. Fluorescence tracing could be performed in ambient light.
View details for DOI 10.1007/s00259-015-3109-3
View details for Web of Science ID 000361996100004
View details for PubMedID 26109329
The most important feature of sentinel node biopsy for prostate cancer procedure is that staging can be improved. Sentinel nodes might be found outside the extended pelvic lymph node dissection template what renders the sentinel node additive of extended pelvic lymph node dissection. At the same time, staging within the template can be further refined. We reviewed the literature regarding the sentinel node biopsy procedure for prostate cancer. PubMed and Embase were searched for all English-language publications from January 1999 to September 2014 by using the keywords as "prostate cancer" and "sentinel lymph node" plus "biopsy" "dissection" and/or "procedure." The present review discusses step-by-step sentinel node biopsy for prostate cancer. Topics of discussion are: (i) preoperative sentinel node mapping (tracers and imaging); (ii) intraoperative sentinel node identification (surgical procedure and outcome); and (iii) novelties to improve sentinel node identification (pre- and intraoperative approaches). Conventional sentinel node mapping is carried out after the injection of a (99m) Tc-based tracer and subsequent preoperative imaging; for example, lymphoscintigraphy and single-photon emission computed tomography/computed tomography. This approach allowed the detection of sentinel nodes outside the extended lymph node dissection template in 3.6-36% of men with intermediate- and high-risk prostate cancer. Hereby, an overall false negative rate of sentinel nodes was reported between 0% and 24.4%. To further refine the intraoperative sampling procedure, novel imaging methods such as fluorescence imaging have been introduced. Prospective randomized comparison studies are required to confirm the added benefit of sentinel template directed nodal dissection. A proper and obtainable end-point of such a study could be the number of removed positive nodes for carrying out nodal dissection with or without sentinel template directed dissection. Similarly, the clinical impact of novel imaging technologies requires further investigation.
View details for DOI 10.1111/iju.12863
View details for Web of Science ID 000362456800002
View details for PubMedID 26173593
Purpose To evaluate the hybrid approach in a large population of patients with melanoma in the head and neck, on the trunk, or on an extremity who were scheduled for sentinel node (SN) biopsy. Materials and Methods This prospective study was approved by the institutional review board. Between March 2010 and March 2013, 104 patients with a melanoma, including 48 women (average age, 54.3 years; range, 18.5-87.4 years) and 56 men (average age, 55.2 years; range, 22.4-77.4 years) (P = .76) were enrolled after obtaining written informed consent. Following intradermal hybrid tracer administration, lymphoscintigraphy and single photon emission computed tomography/computed tomography were performed. Blue dye was intradermally injected prior to the start of the surgical operation (excluding patients with a facial melanoma). Intraoperatively, SNs were initially pursued by using gamma tracing followed by fluorescence imaging (FI) and, when applicable, blue-dye detection. A portable gamma camera was used to confirm SN removal. Collected data included number and location of the preoperatively and intraoperatively identified SNs and the intraoperative number of SNs that were radioactive, fluorescent, and blue. A two-sample test for equality of proportions was performed to evaluate differences in intraoperative SN visualization through FI and blue-dye detection. Results Preoperative imaging revealed 2.4 SNs (range, 1-6) per patient. Intraoperatively, 93.8% (286 of 305) of the SNs were radioactive, 96.7% (295 of 305) of the SNs were fluorescent, while only 61.7% (116 of 188) of the SNs stained blue (P < .0001). FI was of value for identification of near-injection-site SNs (two patients), SNs located in complex anatomic areas (head and neck [28 patients]), and SNs that failed to accumulate blue dye (19 patients). Conclusion The hybrid tracer enables both preoperative SN mapping and intraoperative SN identification in melanoma patients. In the setup of this study, optical identification of the SNs through the fluorescent signature of the hybrid tracer was superior compared with blue dye-based SN visualization.
View details for DOI 10.1148/radiol.14140322
View details for PubMedID 25521776
This study has aimed to evaluate the added value of SPECT-CT scan in the preoperative assessment of sentinel nodes of the presacral and pararectal regions localized outside the standard area of extended pelvic lymphadenectomy for the staging of the pelvis in prostate cancer. SPECT-CT scan can serve as a guide for the excision of these nodes by lymphadenectomy by open surgery or laparoscopy.We evaluated 4 patients with prostate cancer presenting sentinel nodes in the pararectal and presacral regions on SPECT-CT scan performed in addition to lymphoscintigraphy. These patients underwent lymphadenectomy with robot-assisted laparoscopy together with prostatectomy. All of the excised lymph nodes were sent for histopathology study.An average of 6 sentinel nodes per patient were found on SPECT-CT scan with a mean of 2 sentinel nodes in presacral/pararectal región. Lymphadenectomy including these areas was performed. Pararectal/presacral sentinel nodes of all patients depicted by SPECT-CT scan were tumor free on histopathology study. Sentinel nodes (no pararectal/presacral) were positive for malignancy in only one patient.Preoperative SPECT-CT scan is a useful tool to localize the sentinel nodes in pararectal/presacral regions. It can be an anatomic guide for new modalities of laparoscopic surgery such as robot-assisted procedures that can access the pelvic areas visualized with SPECT-CT scan, making excision of these nodes possible.
View details for DOI 10.1016/j.remn.2014.09.001
View details for Web of Science ID 000348696200004
View details for PubMedID 25448419
View details for PubMedID 26160585
Accurate pre- and intraoperative identification of the sentinel node (SN) forms the basis of the SN biopsy procedure. Gamma tracing technologies such as a gamma probe (GP), a 2D mobile gamma camera (MGC) or 3D freehandSPECT (FHS) can be used to provide the surgeon with radioguidance to the SN(s). We reasoned that integrated use of these technologies results in the generation of a "hybrid" modality that combines the best that the individual radioguidance technologies have to offer. The sensitivity and resolvability of both 2D-MGC and 3D-FHS-MGC were studied in a phantom setup (at various source-detector depths and using varying injection site-to-SN distances), and in ten breast cancer patients scheduled for SN biopsy. Acquired 3D-FHS-MGC images were overlaid with the position of the phantom/patient. This augmented-reality overview image was then used for navigation to the hotspot/SN in virtual-reality using the GP. Obtained results were compared to conventional gamma camera lymphoscintigrams. Resolution of 3D-FHS-MGC allowed identification of the SNs at a minimum injection site (100 MBq)-to-node (1 MBq; 1%) distance of 20 mm, up to a source-detector depth of 36 mm in 2D-MGC and up to 24 mm in 3D-FHS-MGC. A clinically relevant dose of approximately 1 MBq was clearly detectable up to a depth of 60 mm in 2D-MGC and 48 mm in 3D-FHS-MGC. In all ten patients at least one SN was visualized on the lymphoscintigrams with a total of 12 SNs visualized. 3D-FHS-MGC identified 11 of 12 SNs and allowed navigation to all these visualized SNs; in one patient with two axillary SNs located closely to each other (11 mm), 3D-FHS-MGC was not able to distinguish the two SNs. In conclusion, high sensitivity detection of SNs at an injection site-to-node distance of 20 mm-and-up was possible using 3D-FHS-MGC. In patients, 3D-FHS-MGC showed highly reproducible images as compared to the conventional lymphoscintigrams.
View details for PubMedID 26069857
The hybrid tracer was introduced to complement intraoperative radiotracing towards the sentinel nodes (SNs) with fluorescence guidance.Improve in vivo fluorescence-based SN identification for prostate cancer by optimising hybrid tracer preparation, injection technique, and fluorescence imaging hardware.Forty patients with a Briganti nomogram-based risk >10% of lymph node (LN) metastases were included. After intraprostatic tracer injection, SN mapping was performed (lymphoscintigraphy and single-photon emission computed tomography with computed tomography (SPECT-CT)). In groups 1 and 2, SNs were pursued intraoperatively using a laparoscopic gamma probe followed by fluorescence imaging (FI). In group 3, SNs were initially located via FI. Compared with group 1, in groups 2 and 3, a new tracer formulation was introduced that had a reduced total injected volume (2.0 ml vs. 3.2 ml) but increased particle concentration. For groups 1 and 2, the Tricam SLII with D-Light C laparoscopic FI (LFI) system was used. In group 3, the LFI system was upgraded to an Image 1 HUB HD with D-Light P system.Hybrid tracer-based SN biopsy, extended pelvic lymph node dissection, and robot-assisted radical prostatectomy.Number and location of the preoperatively identified SNs, in vivo fluorescence-based SN identification rate, tumour status of SNs and LNs, postoperative complications, and biochemical recurrence (BCR).Mean fluorescence-based SN identification improved from 63.7% (group 1) to 85.2% and 93.5% for groups 2 and 3, respectively (p=0.012). No differences in postoperative complications were found. BCR occurred in three pN0 patients.Stepwise optimisation of the hybrid tracer formulation and the LFI system led to a significant improvement in fluorescence-assisted SN identification. Preoperative SPECT-CT remained essential for guiding intraoperative SN localisation.Intraoperative fluorescence-based SN visualisation can be improved by enhancing the hybrid tracer formulation and laparoscopic fluorescence imaging system.
View details for DOI 10.1016/j.eururo.2014.07.014
View details for Web of Science ID 000344694300015
View details for PubMedID 25092539
We explored the clinical feasibility and accuracy of intraoperative navigation based on preoperatively acquired 3-dimensional functional imaging data.Ten patients with penile carcinoma scheduled for sentinel node biopsy were prospectively included in study. After tracer injection preoperative single photon emission computerized tomography/computerized tomography was performed with a reference target fixed on the patient. Repositioning a sterile reference target shortly before surgery allowed 3-dimensional single photon emission computerized tomography/computerized tomography mixed reality based navigation of the ? probe (also containing a reference target) to the sentinel node. The accuracy of the declipse®SPECT navigation approach was determined in relation to the incision site indicated by the conventional ? probe in the coronal plane and the depth estimation measured on axial computerized tomography slices in the sagittal/axial plane.The 3-dimensional mixed reality approach enabled ? probe navigation toward the sentinel node in all 10 patients. The average ± SD navigation error in the coronal and saggital/axial planes was 5.0 ± 3.9 and 5.3 ± 3.9 mm, respectively.To our knowledge this is the first study demonstrating the feasibility of intraoperative navigation based on preoperatively acquired 3-dimensional single photon emission computerized tomography/computerized tomography images. Although confirmation of successful target localization (eg using ? tracing or fluorescence imaging) remains indispensable, this opens the way to translate 3-dimensional functional imaging data to the operating room.
View details for DOI 10.1016/j.juro.2014.03.127
View details for PubMedID 25066868
Recent innovations such as preoperative SPECT/CT, intraoperative imaging using portable devices and a hybrid tracer were evaluated in a multimodality approach for sentinel node (SN) mapping and biopsy in head and neck malignancies.The evaluation included 25 consecutive patients with head and neck malignancies (16 melanomas and 9 oral cavity squamous cell carcinomas). Patients were peritumorally injected with the hybrid tracer ICG-(99m)Tc-nanocolloid. SNs were initially identified with lymphoscintigraphy followed by single photon emission computed tomography (SPECT/CT) 2 hours after tracer administration. During surgery a portable gamma camera in combination with a near-infrared fluorescence camera was used in addition to a handheld gamma ray detection probe to locate the SNs.In all patients the use of conventional lymphoscintigraphy, SPECT/CT and the additional help of the portable gamma camera in one case were able to depict a total of 67 SNs (55 of them visualized on planar images, 11 additional on SPECT/CT and 1 additional with the portable gamma camera). A total of 67 of the preoperatively defined SNs together with 22 additional SNs were removed intraoperatively; 12 out of the 22 additional SNs found during operation were located in the vicinity of the injection site in anatomical areas such as the periauricular or submental regions. The other 10 additional SNs were found by radioguided post-resection control of the excision SN site.In the present series 26% additional SNs were found using the multimodal approach, that incorporates SPECT/CT and intraoperative imaging to the conventional procedure. This approach appears to be useful in malignancies located close to the area of lymphatic drainage such as the periauricular area and the oral cavity.
View details for DOI 10.1016/j.remn.2013.11.005
View details for Web of Science ID 000341804800004
View details for PubMedID 24842707
Conventional sentinel node (SN) mapping is performed by injection of a radiocolloid followed by lymphoscintigraphy to identify the number and location of the primary tumor draining lymph node(s), the so-called SN(s). Over the last decade research has focused on the introduction of new imaging agents that can further aid (surgical) SN identification. Different tracers for SN mapping, with varying sizes and isotopes have been reported, most of which have proven their value in a clinical setting. A major challenge lies in transferring this diagnostic information obtained at the nuclear medicine department to the operating theatre thereby providing the surgeon with (image) guidance. Conventionally, an intraoperative injection of vital blue dye or a fluorescence dye is given to allow intraoperative optical SN identification. However, for some indications, the radiotracer-based approach remains crucial. More recently, hybrid tracers, that contain both a radioactive and fluorescent label, were introduced to allow for direct integration of pre- and intraoperative guidance technologies. Their potential is especially high when they are used in combination with new surgical imaging modalities and navigation tools. Next to a description of the known tracers for SN mapping, this review discusses the application of hybrid tracers during SN biopsy and how the introduction of these new techniques can further aid in translation of nuclear medicine information into the operating theatre.
View details for Web of Science ID 000339308500008
View details for PubMedID 24835293
Sentinel node (SN) biopsy in penile cancer is typically performed using a combination of radiocolloid and blue dye. Recently, the hybrid radioactive and fluorescent tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was developed to combine the beneficial properties of both radio-guidance and fluorescence imaging.To explore the added value of SN biopsy using ICG-(99m)Tc-nanocolloid in patients with penile carcinoma.Sixty-five patients with penile squamous cell carcinoma were prospectively included (January 2011 to December 2012). Preoperative SN mapping was performed using lymphoscintigraphy and single-proton emission computed tomography supplemented with computed tomography (SPECT/CT) after peritumoural injection of ICG-(99m)Tc-nanocolloid. During surgery, SNs were initially approached using a gamma probe, followed by patent blue dye and/or fluorescence imaging. A portable gamma camera was used to confirm excision of all SNs.Patients underwent SN biopsy of the cN0 groin and treatment of the primary tumour.The number and location of preoperatively identified SNs were documented. Intraoperative SN identification rates using radio- and/or fluorescence guidance were assessed and compared with blue dye. Statistical evaluation was performed using a two-sample test for equality of proportions with continuity correction.Preoperative imaging after injection of ICG-(99m)Tc-nanocolloid enabled SN identification in all patients (a total of 183 SNs dispersed over 119 groins). Intraoperatively, all SNs identified by preoperative SN mapping were localised using combined radio-, fluorescence-, and blue dye guidance. Fluorescence imaging enabled visualisation of 96.8% of SNs, while only 55.7% was stained by blue dye (p<0.0001). The tissue penetration of the fluorescent signal, and the rapid flow of blue dye limited the detection sensitivity. A tumour-positive SN was found in seven patients.ICG-(99m)Tc-nanocolloid allows for both preoperative SN mapping and combined radio- and fluorescence-guided SN biopsy in penile carcinoma patients and significantly improves optical SN detection compared with blue dye.
View details for DOI 10.1016/j.eururo.2013.11.014
View details for Web of Science ID 000330572600023
View details for PubMedID 24355132
Conventional sentinel node (SN) mapping is performed by injecting a radiocolloid followed by lymphoscintigraphy (and SPECT/CT imaging). An extra intraoperative injection with blue dye can then allow for optical identification of the SN. In order to improve the current clinical standard, the hybrid tracer indocyanine green (ICG)-(99m)Tc-nanocolloid was introduced, a tracer that is both radioactive and fluorescent. This feasibility study aimed to evaluate the value of a multimodal-based SN biopsy in vulvar cancer.Fifteen patients with vulvar cancer (29 groins) scheduled for SN biopsy were peritumorally injected with ICG-(99m)Tc-nanocolloid followed by lymphoscintigraphy and SPECT/CT imaging to identify the SNs. In thirteen patients, shortly before the start of the operation, blue dye was intradermally injected around the lesion. SNs were harvested using a combination of radiotracing, fluorescence imaging, and optical blue dye detection. A portable gamma camera was used before and after SN excision to confirm excision of the preoperatively defined SNs.Preoperative lymphoscintigraphy and SPECT/CT imaging visualized drainage to 39 SNs in 28 groins. During the operation, 98% (ex vivo 100%) of the SNs were radioactive. With fluorescence imaging 96% of the SNs (ex vivo 100%) could be visualized. Only 65% of the SNs had stained blue at the time of excision.ICG-(99m)Tc-nanocolloid can be used for preoperative SN identification and enables multimodal (radioactive and fluorescent) surgical guidance in patients with vulvar cancer. The addition of fluorescence-based optical guidance offers more effective SN visualization compared to blue dye.
View details for DOI 10.1016/j.ygyno.2013.09.007
View details for Web of Science ID 000327923400041
View details for PubMedID 24051219
Indocyanine green (ICG)-(99m)Tc-nanocolloid is a novel hybrid fluorescent radioactive tracer for sentinel node (SN) biopsy. This study has aimed to evaluate the added value of this novel versatile tracer in a series of patients with different malignancies.Twenty patients (with penile carcinoma, oral cavity tumors, melanoma) were consecutively included between March-May 2012. Planar lymphoscintigraphy was performed 15 min and 2h after injection of ICG-(99m)Tc-nanocolloid followed by SPECT/CT. Blue dye (1 ml) was injected in 14 patients in surgery room. Intraoperatively, SNs were localized using a gamma probe and visualized by optical SN-detection using blue dye and fluorescence imaging. Finally, a portable gamma camera was used to confirm complete SN removal.At least one SN was identified by SPECT/CT in all patients. All SNs (total 68, 100%) were excised using a combination of radio- and fluorescence guidance: 89.7% were intraoperatively localized with the gamma probe. The remaining SNs, located near the injection site, were localized using fluorescence imaging. During the surgery, 97% of the SNs were fluorescent while only 39.2% were stained blue. Ex vivo, all SNs were both radioactive and fluorescent. The SN was positive in 5 patients.Synchronous radio- and fluorescence guided SN biopsy is feasible using ICG-(99m)Tc-nanocolloid. This hybrid approach combines the beneficial properties of both modalities. Adding fluorescence imaging improves optical SN detection compared to blue dye. It has been shown to be especially useful in the localization of SNs near the injection site.
View details for DOI 10.1016/j.remn.2013.02.004
View details for PubMedID 23567320
To provide surgeons with optimal guidance during interventions, it is crucial that the molecular imaging data generated in the diagnostic departments finds its way to the operating room. Sentinel lymph node (SLN) biopsy provides a textbook example in which molecular imaging data acquired in the department of nuclear medicine guides the surgical management of patients. For prostate cancer, in which SLNs are generally located deep in the pelvis, procedures are preferably performed via a (robot-assisted) laparoscopic approach. Unfortunately, in the laparoscopic setting the senses of the surgeon are reduced. This topical review discusses technologic innovations that can help improve surgical guidance during SLN biopsy procedures.
View details for DOI 10.2967/jnumed.112.113746
View details for Web of Science ID 000316939200006
View details for PubMedID 23492883
Over the last several years, epidemiologic data have suggested that the antidiabetes drug metformin (MET), an adenosine monophosphate-activated protein kinase (AMPK) activator, improves progression-free survival of patients with multiple cancers; more than 30 clinical trials are under way to confirm this finding. We postulated that the role of AMPK as a central cellular energy sensor would result in opposite effects on glucose uptake and proliferation, suggesting different roles for (18)F-FDG and 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) in assessing its effectiveness as an antineoplastic agent.Colon cancer cell lines HT29 (human) and MC26 (murine) were treated for 24 or 72 h with a range of MET concentrations (0-10 mM). Western blotting was used to study the activation of AMPK after MET treatment. Glucose uptake and cell proliferation were measured by cell retention studies with either (18)F-FDG or (18)F-FLT. EdU (ethynyl deoxyuridine, a thymidine analog) and annexin-propidium iodide flow cytometry was performed to determine cell cycle S-phase and apoptotic changes. In vivo (18)F-FDG and (18)F-FLT PET images were acquired before and 24 h after MET treatment of HT29 tumor-bearing mice.After 24 h of MET incubation, phosphorylated AMPK levels increased severalfold in both cell lines, whereas total AMPK levels remained unchanged. In cell retention studies, (18)F-FDG uptake increased but (18)F-FLT retention decreased significantly in both cell lines. The numbers of HT29 and MC26 cells in the S phase decreased 36% and 33%, respectively, after MET therapy. Apoptosis increased 10.5-fold and 5.8-fold in HT29 and MC26 cells, respectively, after 72 h of incubation with MET. PET imaging revealed increased (18)F-FDG uptake (mean ± SEM standardized uptake values were 0.71 ± 0.03 before and 1.29 ± 0.11 after MET therapy) (P < 0.05) and decreased (18)F-FLT uptake (mean ± SEM standardized uptake values were 1.18 ± 0.05 before and 0.89 ± 0.01 after MET therapy) (P < 0.05) in HT29 tumor-bearing mice.MET, through activation of the AMPK pathway, produces a dose-dependent increase in tumor glucose uptake while decreasing cell proliferation in human and murine colon cancer cells. Thus, changes in (18)F-FDG uptake after MET treatment may be misleading. (18)F-FLT imaging is a promising alternative that correlates with the tumor response.
View details for DOI 10.2967/jnumed.112.107011
View details for Web of Science ID 000314691200026
View details for PubMedID 23376854
Screening of biomarker expression levels in tumor biopsy samples not only provides an assessment of prognostic and predictive factors, but may also be used for selection of biomarker-specific imaging strategies. To assess the feasibility of using a biopsy specimen for a personalized selection of an imaging agent, the chemokine receptor 4 (CXCR4) was used as a reference biomarker.A hybrid CXCR4 targeting peptide (MSAP-Ac-TZ14011) containing a fluorescent dye and a chelate for radioactive labeling was used to directly compare initial flow cytometry-based target validation in fresh tumor tissue to in vivo single photon emission computed tomography (SPECT) imaging and in vivo and ex vivo fluorescence imaging.Flow cytometric analysis of mouse tumor derived cell suspensions enabled discrimination between 4T1 control tumor lesions (with low levels of CXCR4 expression) and CXCR4 positive early, intermediate and late stage MIN-O lesions based on their CXCR4 expression levels; CXCR4(basal), CXCR4(+) and CXCR4(++) cell populations could be accurately discriminated. Mean fluorescent intensity ratios between expression in MIN-O and 4T1 tissue found with flow cytometry were comparable to ratios obtained with in vivo SPECT/CT and fluorescence imaging, ex vivo fluorescence evaluation and standard immunohistochemistry.The hybrid nature of a targeting imaging agent like MSAP-Ac-TZ14011 enables integration of target selection, in vivo imaging and ex vivo validation using a single agent. The use of biopsy tissue for biomarker screening can readily be expanded to other targeting hybrid imaging agents and can possibly help increase the clinical applicability of tumor-specific imaging approaches.
View details for DOI 10.1371/journal.pone.0048324
View details for Web of Science ID 000314705800005
View details for PubMedID 23326303
View details for PubMedCentralID PMC3543428
For oral cavity malignancies, sentinel lymph node (SLN) mapping is performed by injecting a radiocolloid around the primary tumour followed by lymphoscintigraphy. Surgically, SLNs can then be localized using a handheld gamma ray detection probe. The aim of this study was to evaluate the added value of intraoperative fluorescence imaging to the conventional radioguided procedure. For this we used indocyanine green (ICG)-(99m)Tc-nanocolloid, a hybrid tracer that is both radioactive and fluorescent.Fourteen patients with oral cavity squamous cell carcinoma were peritumourally injected with ICG-(99m)Tc-nanocolloid. SLNs were preoperatively identified with lymphoscintigraphy followed by single photon emission computed tomography (SPECT)/CT for anatomical localization. During surgery, SLNs were detected with a handheld gamma ray detection probe and a handheld near-infrared fluorescence camera. Pre-incision and post-excision imaging with a portable gamma camera was performed to confirm complete removal of all SLNs.SLNs were preoperatively identified using the radioactive signature of ICG-(99m)Tc-nanocolloid. Intraoperatively, 43 SLNs could be localized and excised with combined radio- and fluorescence guidance. Additionally, in four patients, an SLN located close to the primary injection site (in three patients this SLN was located in level I) could only be intraoperatively localized using fluorescence imaging. Pathological analysis of the SLNs revealed a metastasis in one patient.Combined preoperative SLN identification and intraoperative radio- and fluorescence guidance during SLN biopsies for oral cavity cancer proved feasible using ICG-(99m)Tc-nanocolloid. The addition of fluorescence imaging was shown to be of particular value when SLNs were located in close proximity to the primary tumour.
View details for DOI 10.1007/s00259-012-2129-5
View details for PubMedID 22526966
Fluorescent tracers can provide anatomical and functional information without altering the visual surgical field. Despite the advances that are being made in tracer development, only a few fluorescent tracers are available for urological interventions.Protoporphyrin IX, hypericin, fluorescein, and indocyanine green were shown to facilitate surgical resection in various ways. Hybrid imaging agents, combining radio and fluorescent labels, have shown improved integration between preoperative and intraoperative imaging. With the rise of surgical fluorescence guidance, various camera systems have been developed that are tailored for optimal detection of the fluorochromes of interest.In this review, the basics of fluorescence-guided surgery, including tracer and hardware requirements are discussed.
View details for DOI 10.1097/MOU.0b013e3283501869
View details for Web of Science ID 000300042900005
View details for PubMedID 22262249
A series of nine luminescent cyclometalated octahedral iridium(III) tris(2-phenylpyridine) complexes has been synthesized, functionalized with three different amino acids (glycine, alanine, and lysine), on one, two, or all three of the phenylpyridine ligands. All starting complexes and final compounds have been fully analyzed by one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy, and photophysical data have been obtained for all the mono-, bis-, and tri- substituted iridium(III) complexes. Cellular uptake and localization have been studied with flow cytometry and confocal microscopy, respectively. Confocal experiments demonstrate that all nine substituted iridium(III) complexes show variable uptake in the tumor cells. The monosubstituted iridium(III) complexes give the highest cellular uptake, and the series substituted with lysines shows the highest toxicity. This systematic study of amino acid-functionalized Ir(ppy)(3) complexes provides guidelines for further functionalization and possible implementation of luminescent iridium complexes, for example, in (automated) peptide synthesis or biomarker specific targeting.
View details for DOI 10.1021/ic201860s
View details for Web of Science ID 000300466300019
View details for PubMedID 22303934
View details for Web of Science ID 000208619400190
Pathology is fundamental in grading, staging, and treatment planning of malignancies. One relatively novel biomarker that may become more important in therapy and diagnostics is the chemokine receptor 4 (CXCR4). Ac-TZ14011 peptide derivatives, functionalized with a radiolabel, can be used for molecular imaging of tumors. Direct fluorescent labeling of the small peptide Ac-TZ14011 with the fluorescent dye fluorescein isothiocyanate (FITC), however, provides an alternative for the detection of CXCR4 expression levels in cells and tumor tissue. In this study, Ac-TZ14011-FITC was validated for CXCR4 staining in human breast cancer cell lines MDAMB231 and MDAMB231(CXCR4+) during flow cytometric analysis. Its efficacy was compared to commercially available antibodies. Competition experiments validated the staining specificity. Confocal imaging revealed that CXCR4 staining was predominantly found on the cell membrane and/or in vesicles formed after endocytosis. Next to being able to differentiate "high" and "low" CXCR4-expressing tumor cells, the fluorescent peptide demonstrates potential in fluorescent immunohistochemistry of tumor tissue. Ac-TZ14011-FITC was able to differentiate MDAMB231 from MDAMB231(CXCR4+) tumor cells and tissue, proving its applicability in the detection of differences in CXCR4 expression levels.
View details for PubMedID 21804919
The antagonistic Ac-TZ14011 peptide, which binds to the chemokine receptor 4, has been labeled with a multifunctional single attachment point reagent that contains a DTPA chelate and a fluorescent dye with Cy5.5 spectral properties. Flow cytometry and confocal microscopy showed that the bimodal labeled peptide gave a specific receptor binding that is similar to monofunctionalized peptide derivatives. Therefore, the newly developed bimodal peptide derivative can be used in multimodal imaging applications.
View details for DOI 10.1021/bc2000947
View details for Web of Science ID 000290691600002
View details for PubMedID 21480671
Accurate tumor excision is crucial in the locoregional treatment of cancer, and for this purpose, surgeons often rely on guide wires or radioactive markers for guidance toward the lesion. Further improvement may be obtained by adding optical guidance to currently used methods, in the form of intra-operative fluorescence imaging. To achieve such a multimodal approach, we have generated markers that can be used in a pre-, intra-, and post-operative setting, based on a cocktail of a dual-emissive inorganic dye, lipids, and pertechnetate. Phantom experiments demonstrate that these seeds can be placed accurately around a surrogate tumor using ultrasound. Three-dimensional bracketing provides delineation of the entire lesion. Combined with the multimodal nature, this provides the opportunity to predetermine the resection margins by validating the placement accuracy using multiple imaging modalities (namely, x ray, MRI, SPECT/CT, and ultrasound). The dual-emissive fluorescent properties of the dye provide the unique opportunity to intra-operatively estimate the depth of the seed in the tissue via multispectral imaging: emission green ?max=520 nm?5 mm penetration versus emission red ?max=660 nm?12 mm penetration. By using particles with different colors, the original geographic orientation of the excised tissue can be determined.
View details for DOI 10.1117/1.3503955
View details for Web of Science ID 000284837400043
View details for PubMedID 21054115