Professional Education
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Doctor of Medicine, Universitat Wien (2007)
Bio
Publications
All Publications
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PSMA- and GRPR-targeted PET: Results from 50 Patients with Biochemically Recurrent Prostate Cancer.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
2021
Abstract
Rationale: Novel radiopharmaceuticals for positron emission tomography (PET) are evaluated for the diagnosis of biochemically recurrent prostate cancer (BCR PC). Here, we compare the gastrin releasing peptide receptors (GRPR) - targeting 68Ga-RM2 with the prostate specific membrane antigen (PSMA) - targeting 68Ga-PSMA11 and 18F-DCFPyL. Methods: Fifty patients had both 68Ga-RM2 PET/MRI and 68Ga-PSMA11 PET/CT (n = 23) or 18F-DCFPyL PET/CT (n = 27) at an interval ranging from 1 to 60 days (mean±SD: 15.8±17.7). Maximum standardized uptake values (SUVmax) were collected for all lesions. Results: RM2 PET was positive in 35 and negative in 15 of the 50 patients. PSMA PET was positive in 37 and negative in 13 of the 50 patients. Both scans detected 70 lesions in 32 patients. Forty-three lesions in 18 patients were identified only on one scan: 68Ga-RM2 detected 7 more lesions in 4 patients, while PSMA detected 36 more lesions in 13 patients. Conclusion: 68Ga-RM2 remains a valuable radiopharmaceutical even when compared with the more widely used 68Ga-PSMA11/18F-DCFPyL in the evaluation of BCR PC. Larger studies are needed to verify that identifying patients for whom these two classes of radiopharmaceuticals are complementary may ultimately allow for personalized medicine.
View details for DOI 10.2967/jnumed.120.259630
View details for PubMedID 33674398
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High quality imaging and dosimetry for yttrium-90 (90Y) liver radioembolization using a SiPM-based PET/CT scanner.
European journal of nuclear medicine and molecular imaging
2021
Abstract
PURPOSE: Transarterial radioembolization (TARE) with yttrium-90 (90Y) microspheres is a liver-directed treatment for primary and secondary hepatic malignancies. Personalized dosimetry aims for maximum treatment effect and reduced toxicity. We aimed to compare pre-treatment voxel-based dosimetry from 99mTc macroaggregated albumin (MAA) SPECT/CT with post-treatment 90Y PET/CT for absorbed dose values, and to evaluate image quality of 90Y SiPM-based PET/CT.METHODS: Forty-two patients (28 men, 14 women, mean age: 67 ± 11 years) with advanced hepatic malignancies were prospectively enrolled. Twenty patients were treated with glass and 22 with resin microspheres. Radiation absorbed doses from planning 99mTc-MAA SPECT/CT and post-therapy 90Y PET/CT were assessed. 90Y PET/CT images were acquired for 20 min and reconstructed to produce 5-, 10-, 15-, and 20-min datasets, then evaluated using the 5-point Likert scale.RESULTS: The mean administered activity was 3.44 ± 1.5 GBq for glass and 1.62 ± 0.7 GBq for resin microspheres. The mean tumor absorbed doses calculated from 99mTc-MAA SPECT/CT and 90Y PET/CT were 175.69 ± 113.76 Gy and 193.58 ± 111.09 Gy (P = 0.61), respectively for glass microspheres; they were 60.18 ± 42.20 Gy and 70.98 ± 49.65 Gy (P = 0.37), respectively for resin microspheres. The mean normal liver absorbed doses from 99mTc-MAA SPECT/CT and 90Y PET/CT were 32.70 ± 22.25 Gy and 30.62 ± 20.09 Gy (P = 0.77), respectively for glass microspheres; they were 18.33 ± 11.08 Gy and 24.32 ± 15.58 Gy (P = 0.17), respectively for resin microspheres. Image quality of 90Y PET/CT at 5-, 10-, 15-, and 20-min scan time showed a Likert score of 3.6 ± 0.54, 4.57 ± 0.58, 4.84 ± 0.37, and 4.9 ± 0.3, respectively.CONCLUSIONS: 99mTc-MAA SPECT/CT demonstrated great accuracy for treatment planning dosimetry. SiPM-based PET/CT scanner showed good image quality at 10-min scan time, acquired in one bed position. A PET/CT scan time of 5 min showed acceptable image quality and suffices for dosimetry and treatment verification. This allows for inclusion of 90Y PET/CT in busy routine clinical workflows. Studies with larger patient cohorts are needed to confirm these findings.
View details for DOI 10.1007/s00259-021-05188-4
View details for PubMedID 33443618
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Pulmonary large cell neuroendocrine carcinoma (LCNEC) with confirmed liver metastases negative on 18F-FDG and 68Ga-DOTATATE PET.
Radiology case reports
2020; 15 (12): 2698–2700
Abstract
Lung neuroendocrine neoplasms (NENs) encompass the low-, intermediate-, and high-grade entities. Differentiated NENs overexpress somatostatin receptors, which are targeted by 68Ga-DOTA-conjugated peptides in molecular imaging with positron emission tomography. Less differentiated NENs may have lost their expression of somatostatin receptors and thus show lower uptake of 68Ga-DOTA-peptides; however, these tumors express GLUT-1 and can be imaged with (18)F-fluordeoxyglucose (FDG). We report the case of a 72-year-old patient with a poorly differentiated, high grade lung NEN, which was 18F-FDG-positive at initial diagnosis. After treatment and remission, the patient had histologically confirmed relapse in the liver. Interestingly, these hepatic metastases did not demonstrated radiopharmaceutical uptake at neither 18F-FDG nor 68Ga-DOTATATE positron emission tomography/computed tomography.
View details for DOI 10.1016/j.radcr.2020.10.023
View details for PubMedID 33117470
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A prospective study of Ga-68-RM2 PET/MRI in patients with biochemically recurrent prostate cancer and negative conventional imaging.
LIPPINCOTT WILLIAMS & WILKINS. 2020
View details for Web of Science ID 000560368306300
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Prospective evaluation of F-18-DCFPyL PET/CT in biochemically recurrent prostate cancer: Analysis of lesion localization and distribution.
AMER SOC CLINICAL ONCOLOGY. 2020
View details for Web of Science ID 000560368302399
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Peptide receptor radionuclide therapy (PRRT) for neuroendocrine tumors (NET): A two-year single institution experience
SOC NUCLEAR MEDICINE INC. 2020
View details for Web of Science ID 000568290501374
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A pilot study of F-18-FSPG SiPM-based PET/CT in patients referred for exclusion of active cardiac sarcoidosis and negative or non-diagnostic F-18-FDG PET/CT
SOC NUCLEAR MEDICINE INC. 2020
View details for Web of Science ID 000568290501539
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Ga-68-RM2 PET/CT in Patients with Newly Diagnosed Intermediate- or High-Risk Prostate Cancer
SOC NUCLEAR MEDICINE INC. 2020
View details for Web of Science ID 000568290501196
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Determining optimal uptake time for Ga-68-labeled radiopharmaceuticals targeting gastrin-releasing peptide receptors with a modified NEMA phantom.
SOC NUCLEAR MEDICINE INC. 2020
View details for Web of Science ID 000568290501580
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Ga-68-PSMA-11 PET/MR Imaging before prostatectomy: correlation with surgical pathology and two-year follow up
SOC NUCLEAR MEDICINE INC. 2020
View details for Web of Science ID 000568290500168
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PSMA-and GRPR-targeted PET: Preliminary Results in Patients with Biochemically Recurrent Prostate Cancer
SOC NUCLEAR MEDICINE INC. 2020
View details for Web of Science ID 000568290501184
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Toxicity identification and evaluation of peptide receptor radionuclide therapy (PRRT) for neuroendocrine tumors (NETs)
SOC NUCLEAR MEDICINE INC. 2020
View details for Web of Science ID 000568290501378
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INTERIM ANALYSIS RESULTS OF A PROSPECTIVE STUDY OF (68)GA-RM2 PET/MRI IN PATIENTS WITH BIOCHEMICALLY RECURRENT PROSTATE CANCER AND NEGATIVE CONVENTIONAL IMAGING
LIPPINCOTT WILLIAMS & WILKINS. 2020: E1118
View details for Web of Science ID 000527010300463
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Single institution experience with peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumors (NET)
AMER SOC CLINICAL ONCOLOGY. 2020
View details for Web of Science ID 000530922700601
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Imaging the Distribution of Gastrin Releasing Peptide Receptors in Cancer.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
2020
Abstract
Targeting tumor-expressed receptors using selective molecules for diagnostic, therapeutic or both diagnostic and therapeutic (theragnostic) purposes is a promising approach in oncological applications. Such approaches have increased significantly over the past decade. Peptides such as gastrin-releasing peptide receptors (GRPR) targeting radiopharmaceuticals are small molecules with fast blood clearance and urinary excretion. They demonstrate good tissue diffusion, low immunogenicity, and highly selective binding to their target cell-surface receptors. They are also easily produced. GRPR, part of the bombesin (BBN) family, are overexpressed in many tumors, including breast and prostate cancer, and therefore represent an attractive target for future development.
View details for DOI 10.2967/jnumed.119.234971
View details for PubMedID 32060215
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The Effect of Various β Values on Image Quality and Semiquantitative Measurements in 68Ga-RM2 and 68Ga-PSMA-11 PET/MRI Images Reconstructed With a Block Sequential Regularized Expectation Maximization Algorithm.
Clinical nuclear medicine
2020
Abstract
To compare the block sequential regularized expectation maximization (BSREM) algorithm with the ordered subsets expectation maximization (OSEM) algorithm and to evaluate how different penalty factors (b values) influence image quality and SUV measurements.We analyzed data from 78 prostate cancer patients who underwent Ga-RM2 (n = 42) or Ga-prostate-specific membrane antigen (PSMA)-11 (n = 36) PET/MRI. The raw PET data were retrospectively reconstructed using both time-of-flight (TOF)-BSREM with b values of 250, 350, 500, 750, and 1000 and TOF-OSEM. Each reconstruction was reviewed independently by 3 nuclear medicine physicians and scored qualitatively using a Likert scale (1 = poor, 5 = excellent quality). SUV measurements were analyzed as well.Fifty-seven lesions were detected (21 on Ga-RM2 and 36 on Ga-PSMA-11 PET/MRI); SUVmax decreased with the increase of β values for both tracers. Background noise (SUVsd) decreased with increasing of β values for both tracers. The mean ± SD scores for Ga-RM2 PET images were 2.4 ± 0.5 for b = 250 reconstructions, 3.2 ± 0.6 for b = 350, 4 ± 0.6 for b = 500, 4.5 ± 0.5 for b = 750, 4.4 ± 0.7 for b = 1000, and 3.4 ± 0.6 for TOF-OSEM. The mean ± SD scores for Ga-PSMA-11 PET images were 3.2 ± 0.8 for b = 250 reconstructions, 4.1 ± 0.8 for b = 350, 4.7 ± 0.6 for b = 500, 4.8 ± 0.4 for b = 750, 4.7 ± 0.6 for b = 1000, and 3.8 ± 0.5 for TOF-OSEM.Time-of-flight-BSREM algorithm improves image quality. Different b values should be used for different Ga-labeled radiopharmaceuticals such as those targeting GRPR and PSMA receptors. Once selected, the same b value should be consistently used because SUVmax measurements differ with different b values.
View details for DOI 10.1097/RLU.0000000000003075
View details for PubMedID 32433170
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Prospective Evaluation in an Academic Center of 18F-DCFPyL PET/CT in Biochemically Recurrent Prostate Cancer: A Focus on Localizing Disease and Changes in Management.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
2019
Abstract
18F-DCFPyL is a promising PET radiopharmaceutical targeting prostate specific membrane antigen (PSMA). We present our experience in this single academic center prospective study evaluating the positivity rate of 18F-DCFPyL PET/CT in patients with biochemical recurrence (BCR) of prostate cancer (PC). Methods: We prospectively enrolled 72 men (52-91 years old, mean±SD: 71.5±7.2) with BCR after primary definitive treatment with prostatectomy (n = 42) or radiotherapy (n = 30). The presence of lesions compatible with PC was evaluated by two independent readers. Fifty-nine patients had concurrent scans with at least one other conventional scan: bone scan (24), CT (21), MR (20), 18F-Fluciclovine PET/CT (18) and/or 18F-NaF PET (14). Findings from 18F-DCFPyL PET/CT were compared with those from other modalities. Impact on patient management based on 18F-DCFPyL PET/CT was recorded from clinical chart review. Results: 18F-DCFPyL PET/CT had an overall positivity rate of 85%, which increased with higher prostate specific antigen (PSA) levels (ng/mL): 50% (PSA<0.5), 69% (0.5≤PSA<1), 100% (1≤PSA<2), 91% (2≤PSA<5) and 96% (PSA≥5), respectively. 18F-DCFPyL PET detected more lesions than conventional imaging. For anatomic imaging, 20/41 (49%) CT/MRI had congruent findings with 18F-DCFPyL, while 18F-DCFPyL PET was positive in 17/41 (41%) cases with negative CT/MRI. For bone imaging, 26/38 (68%) bone scan/18F-NaF PET were congruent with 18F-DCFPyL PET, while 18F-DCFPyL PET localized bone lesions in 8/38 (21%) patients with negative bone scan/18F-NaF PET. In 8/18 (44%) patients, 18F-Fluciclovine PET had located the same lesions as the 18F-DCFPyL PET, while 5/18 (28%) patients with negative 18F-Fluciclovine had positive 18F-DCFPyL PET findings and 1/18 (6%) patient with negative 18F-DCFPyL had uptake in the prostate bed on 18F-Fluciclovine PET. In the remaining 4/18 (22%) patients, 18F-DCFPyL and 18F-Fluciclovine scans showed different lesions. Lastly, 43/72 (60%) patients had treatment changes after 18F-DCFPyL PET and, most noticeably, 17 of these patients (24% total) had lesion localization only on 18F-DCFPyL PET, despite negative conventional imaging. Conclusion: 18F-DCFPyL PET/CT is a promising diagnostic tool in the work-up of biochemically recurrent prostate cancer given the high positivity rate as compared to FDA-approved currently available imaging modalities and its impact on clinical management in 60% of patients.
View details for DOI 10.2967/jnumed.119.231654
View details for PubMedID 31628216
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Physiological 68Ga-RM2 uptake in patients with biochemically recurrent prostate cancer: an atlas of semi-quantitative measurements.
European journal of nuclear medicine and molecular imaging
2019
Abstract
AIM: 68Ga-RM2 is a bombesin (BBN) analog that targets the gastrin releasing peptide receptors (GRPR) overexpressed in many cancer cells, including prostate cancer (PC). It has been reported to successfully detect primary and recurrent PC. Here, we describe the distribution and range of physiological uptake of 68Ga-RM2 in 95 patients with biochemically recurrent (BCR) PC.MATERIALS AND METHODS: Ninety-five participants had simultaneous PET/MRI for BCR PC and were prospectively enrolled in this study. Maximum standardized uptake value (SUVmax) and mean standardized uptake value (SUVmean) were measured in 24 normal anatomical structures for each participant. Three readers evaluated the images independently. Uptake in various normal tissues was classified into 4 different categories: no significant uptake if SUVmean was less than SUVmean of the aortic arch (AA); mild if SUVmean was less or equal to 2.5, but higher than SUVmean of the AA; moderate if SUVmean was higher than 2.5, but less or equal to 5; intense if SUVmean was higher than 5.RESULTS: The most intense uptake was observed in the urinary bladder, due to excretion of the radiotracer. No significant uptake was seen in the brain, salivary glands, lungs, myocardium, skeleton, muscles, and fat. Liver, spleen, and adrenal glands had mostly no significant uptake; the gastrointestinal tract had intense physiological uptake, with pancreas being the organ with the highest SUVmax measurements (average SUVmax 64.91). Mild and moderate uptake was measured in the esophagus (average SUVmax 3.99), while the stomach wall, duodenum, and rectum had mild uptake (average SUVmax 2.49, 3.42, and 3.58, respectively).CONCLUSIONS: 68Ga-RM2 has been mostly evaluated for PC detection, but it can be used for other tumors overexpressing GRPR such as breast cancer. This atlas of normal biodistribution and SUV measurements in healthy tissues will help physicians distinguish between physiological vs. pathological uptake, as well as potentially assist with planning future studies using GRPR targeting radiopharmaceuticals.
View details for DOI 10.1007/s00259-019-04503-4
View details for PubMedID 31478089
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F-18-FPPRGD(2) PET/CT in patients with metastatic renal cell cancer
EUROPEAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING
2019; 46 (7): 1518–23
View details for DOI 10.1007/s00259-019-04295-7
View details for Web of Science ID 000468983000017
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Preliminary Results of a Prospective Study of Ga-68-RM2 PET/MRI for Detection of Recurrent Prostate Cancer in Patients with Negative Conventional Imaging
SOC NUCLEAR MEDICINE INC. 2019
View details for Web of Science ID 000473116801014
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Prospective evaluation of Ga-68-RM2 PET/MRI and Ga-68-PSMA11 PET/CT in patients with biochemical recurrence of prostate cancer
SOC NUCLEAR MEDICINE INC. 2019
View details for Web of Science ID 000473116800587
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Comparison of three interpretation criteria of Ga-68-PS A PET based on in er and intra-reader agreement
SOC NUCLEAR MEDICINE INC. 2019
View details for Web of Science ID 000473116801600
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Prospective Comparison of F-18-DCFPyL PET/CT with F-18-NaF PET/CT for Detection of Skeletal Metastases in Biochemically Recurrent Prostate Cancer
SOC NUCLEAR MEDICINE INC. 2019
View details for Web of Science ID 000473116801621
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Clinical Follow-Up after Imaging and Dosimetry for Yttrium-90 (Y-90) Liver Radioembolization Using a SiPM-Based PET/CT Scanner
SOC NUCLEAR MEDICINE INC. 2019
View details for Web of Science ID 000473116800126
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18F-FPPRGD2 PET/CT in patients with metastatic renal cell cancer.
European journal of nuclear medicine and molecular imaging
2019
Abstract
PURPOSE: The usefulness of positron emission tomography/computed tomography (PET/CT) using (18F)-2-fluoropropionyl-labeled PEGylated dimeric arginine-glycine-aspartic acid peptide [PEG3-E{c(RGDyk)}2] (18F-FPPRGD2) in patients with metastatic renal cell cancer (mRCC) has not been evaluated; therefore, we were prompted to conduct this pilot study.METHODS: Seven patients with mRCC were enrolled in this prospective study. 18F-FPPRGD2 and 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) PET/CT images were evaluated in a per-lesion analysis. Maximum standardized uptake value (SUVmax) and tumor-to-background ratio (T/B) were measured for all detected lesions, both before and after starting antiangiogenic therapy.RESULTS: Sixty lesions in total were detected in this cohort. SUVmax from 18F-FPPRGD2 PET/CT was lower than that from 18F-FDG PET/CT (4.4±2.9 vs 7.8±5.6, P<0.001). Both SUVmax and T/B from 18F-FPPRGD2 PET/CT decreased after starting antiangiogenic therapy (SUVmax, 4.2±3.2 vs 2.6±1.4, P=0.003; T/B, 3.7±3.2 vs 1.5±0.8, P<0.001). Average changes in SUVmax and T/B were-29.3±23.6% and-48.1±28.3%, respectively.CONCLUSIONS: 18F-FPPRGD2 PET/CT may be an useful tool for monitoring early response to antiangiogenic therapy in patients with mRCC. These preliminary results need to be confirmed in larger cohorts.
View details for PubMedID 30850872
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Comparison of three interpretation criteria of 68Ga-PSMA11 PET based on inter- and intra-reader agreement.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
2019
Abstract
Positron emission tomography (PET) using radiolabeled prostate specific membrane antigen (PSMA) is now more and more widely adopted as a valuable tool to evaluate patients with prostate cancer (PC). Recently, three different criteria for interpretation of PSMA PET were published: European Association of Nuclear Medicine (EANM) criteria, prostate cancer molecular imaging standardized evaluation (PROMISE) criteria, and PSMA-reporting and data system (PSMA-RADS). We compared these three criteria in terms of inter-reader, intra-reader, and inter-criteria agreement. Methods: Data from 104 patients prospectively enrolled in research protocols at our institution were retrospectively reviewed. The cohort consisted of two groups: 47 patients (mean age: 64.2 years old) who underwent Glu-NH-CO-NH-Lys-(Ahx)-[68Ga(HBED-CC)] (68Ga-PSMA11) PET/magnetic resonance imaging (MRI) for initial staging of biopsy-proven intermediate- or high-risk PC, and 57 patients (mean age: 70.5 years old) who underwent 68Ga-PSMA11 PET/computed tomography (CT) due to biochemically recurrent (BCR) PC. Three nuclear medicine physicians independently evaluated all 68Ga-PSMA11 PET/MRI and PET/CT studies according to the three interpretation criteria. Two of them reevaluated all studies 6 months later in the same manner and blinded to the initial reading. Gwet's AC was calculated to evaluate inter- and intra-reader, and inter-criteria agreement based on the following sites: local lesion (primary tumor or prostate bed after radical prostatectomy), lymph node metastases, and other metastases. Results: In the PET/MRI group, inter-reader, intra-reader, and inter-criteria agreements were substantial to almost perfect in any sites according to all of the three criteria. In the PET/CT group, inter-reader agreement was substantial to almost perfect except judgement of distant metastases based on PSMA-RADS (Gwet's AC = 0.57, moderate agreement), in which the most frequent cause of disagreement was lung nodules. Intra-reader agreements were substantial to almost perfect in any sites according to all of the three criteria. Inter-criteria agreements of each site were also substantial to almost perfect. Conclusion: Although the three published criteria have good inter-reader and intra-reader reproducibility in evaluating 68Ga-PSMA11 PET, there are factors bringing inter-reader disagreement. This indicates that further work is needed to address the issue.
View details for DOI 10.2967/jnumed.119.232504
View details for PubMedID 31562226
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The Role of PET/CT in the Imaging of Pancreatic Neoplasms.
Seminars in ultrasound, CT, and MR
2019; 40 (6): 500–508
Abstract
Pancreas cancer is a complex disease and its prognosis is related to the origin of the tumor cell as well as the stage of disease at the time of diagnosis. Pancreatic adenocarcinomas derive from the exocrine pancreas and are the fourth leading cause of cancer-related deaths in the United States, while well-differentiated pancreatic neuroendocrine tumors (pNETs) derived from the endocrine part of the pancreas are rare and characterized by a slow growth and good life expectancy. Surgery is the only curative treatment approach, and an accurate assessment of resectability is of paramount importance in order to avoid futile procedures. The role of molecular imaging with positron emission tomography and computed tomography ranges from indispensable for pNETs to controversial for certain scenarios in pancreatic adenocarcinomas. This review article aims to overview molecular pancreatic imaging.
View details for DOI 10.1053/j.sult.2019.04.006
View details for PubMedID 31806148