Bio

Clinical Focus


  • Diagnostic Radiology
  • Interventional Oncology
  • Image-Guided Surgery
  • Interventional Radiology
  • Minimally invasive therapy
  • Radiology
  • Catheter based therapies

Academic Appointments


Administrative Appointments


  • Director, Clinical Operations (IR), Stanford Univ Med Ctr, Division of Interventional Radiology (2008 - Present)
  • Education Director, Interventional Radiology, Stanford (2006 - Present)

Professional Education


  • Fellowship:New York University Med Ctr (2002) NY
  • Residency:George Washington University (2001) DC
  • Fellowship:The Children's Hospital of Philadelphia (2003) PA
  • Residency:Medical College of Ohio (1998) OH
  • Internship:Good Samaritan Hospital (1997) OH
  • Board Certification: Diagnostic Radiology, American Board of Radiology (2001)
  • Board Certification: Vascular and Interventional Radiology, American Board of Radiology (2006)
  • Medical Education:Topiwala National Medical College/BYL Nair Charitable Hospital (1996) India
  • MD, U of Penn, Philadelphia, Interventional Radiology (2003)
  • MD, NYU, New York, Neuroradiology (2002)
  • MD, GW Univ, Washington DC, Radiology (2001)

Research & Scholarship

Current Research and Scholarly Interests


Interventional Oncology: Percutaneous and transarterial interventions for diagnosis and treatment of primary and metastatic tumors (lung, liver and renal)


Research Interest:
Gastrointestinal and Hepatic Oncology

Clinical Trials


  • Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis Recruiting

    The purpose of this study is to determine if the use of adjunctive Pharmacomechanical Catheter Directed Thrombolysis, which includes the intrathrombus administration of rt-PA--Activase (Alteplase),can prevent the post-thrombotic syndrome(PTS)in patients with symptomatic proximal deep vein thrombosis(DVT)as compared with optimal standard DVT therapy alone.

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  • Efficacy Evaluation of TheraSphere Following Failed First Line Chemotherapy in Metastatic Colorectal Cancer Not Recruiting

    The effectiveness and safety of TheraSphere will be evaluated in patients with colorectal cancer with metastases in the liver, who are scheduled to receive second line chemotherapy. All patients receive the standard of care chemotherapy with or without the addition of TheraSphere.

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, 650-725-9810.

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  • ExAblate (Magnetic Resonance-guided Focused Ultrasound Surgery) Treatment of Metastatic Bone Tumors for the Palliation of Pain Not Recruiting

    A Pivotal Study to Evaluate the Effectiveness and Safety of ExAblate Treatment of Metastatic Bone and Multiple Myeloma Tumors for the Palliation of Pain in Patients Who are not Candidates for Radiation Therapy

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • Pulmonary Embolism Response to Fragmentation, Embolectomy, & Catheter Thrombolysis: PERFECT Recruiting

    A prospective observational study to evaluate the safety and effectiveness data of catheter-directed therapy (CDT) including percutaneous mechanical thrombectomy (PMT) for treatment of acute pulmonary embolism (PE)

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  • CyberKnife Radiosurgical Treatment of Inoperable Early Stage Non-Small Cell Lung Cancer Not Recruiting

    The purpose of this study is to assess the short and long-term outcomes after CyberKnife stereotactic radiosurgery for early stage non-small cell lung cancer (NSCLC) in patients who are medically inoperable.

    Stanford is currently not accepting patients for this trial. For more information, please contact Lisa Zhou, (650) 736 - 4112.

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  • Combination SBRT (Stereotactic Body Radiotherapy) With TACE (Transarterial Chemoembolization) for Unresectable Hepatocellular Carcinoma Not Recruiting

    To establish the efficacy and toxicity of TACE combined with SBRT

    Stanford is currently not accepting patients for this trial. For more information, please contact Laurie Ann Columbo, 650-736-0792.

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  • Transarterial Chemoembolization vs CyberKnife for Recurrent Hepatocellular Carcinoma Not Recruiting

    Primary Objective: To compare the efficacy of TACE vs. CyberKnife SBRT in the treatment of locally recurrent HCC after initial TACE. Secondary Objectives: 1. To determine the progression-free survival of TACE vs. CyberKnife SBRT 2. To determine the overall survival of TACE vs. CyberKnife SBRT for locally recurrent HCC 3. To determine the toxicities associated with TACE or CyberKnife SBRT for the treatment of recurrent HCC.

    Stanford is currently not accepting patients for this trial. For more information, please contact Laurie Ann Columbo, (650) 736 - 0792.

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  • A Phase 2b Study of Modified Vaccinia Virus to Treat Patients Advanced Liver Cancer Who Failed Sorafenib Not Recruiting

    This study is to determine whether JX-594 (Pexa-Vec) plus best supportive care is more effective in improving survival than best supportive care in patients with advanced Hepatocellular Carcinoma (HCC) who have failed sorafenib.

    Stanford is currently not accepting patients for this trial. For more information, please contact Fizaa Ahmed, (650) 725 - 6409.

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  • Impact of C-arm CT in Patients With HCC Undergoing TACE: Optimal Imaging Guidance Not Recruiting

    Patients will be enrolled based on presence of HCC and eligibility for TACE. They will be randomized to one of two arms for imaging navigation to the optimal catheter location for chemotherapy injection to treat the first (possibly sole) tumor target. The two arms will be: TACE using F and DSA only, or TACE using F, DSA, and CACT. Navigation to subsequent treatment targets in all patients will be done with fluoroscopy, CACT, and DSA, as is standard of care at Stanford University Medical Center, and is not part of the study. Vascular complexity, which affects navigation difficulty and thus the need for imaging, will be assessed separately for use in data analysis by two radiologists on a four-point scale.

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • FILTER - Filter Initial & Long Term Evaluation After Placement and Retrieval (Including Laser-Assisted Retrieval) Registry Recruiting

    A data registry for all patients who undergo IVC (Inferior Vena Cava) filter placement or retrieval at Stanford. Potential enrollees will already be undergoing the procedure. If patients are willing, they will be prospectively enrolled prior to the procedure. As part of the study, chart and clinical data reviews will be used to track patient progress and response to the treatment.

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  • The GORE Viabahn Endoprosthesis for the Treatment of Venous Occlusions and Stenoses Recruiting

    To study the safety and efficacy of drug coated stents for the treatment of venous occlusions and stenoses in the lower extremity. The use of the device for the treatment of peripheral arterial disease is approved by the FDA, however, the use of the device in venous occlusions and stenoses, although performed by some practitioners, has not yet been studied in detail.

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  • Chemoembolization With or Without Sorafenib Tosylate in Treating Patients With Liver Cancer That Cannot Be Removed By Surgery Recruiting

    This randomized phase III trial is studying chemoembolization and sorafenib tosylate to see how well they work compared with chemoembolization alone in treating patients with liver cancer that cannot be removed by surgery. Drugs used in chemotherapy, such as doxorubicin hydrochloride, mitomycin, and cisplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Chemoembolization kills tumor cells by carrying drugs directly into the tumor and blocking the blood flow to the tumor. Sorafenib tosylate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. It is not yet known whether giving chemoembolization together with sorafenib tosylate is more effective than chemoembolization alone in treating patients with liver cancer.

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  • To Evaluate the Safety and Efficacy for GORE TAG Thoracic Endoprosthesis in the Treatment of Thoracic Aortic Disease Not Recruiting

    Study Type: Interventional Study Design: Treatment, Open Label, Uncontrolled, Single Group Assignment, Safety and Efficacy study Official Title: A Clinical Study of the TAG Thoracic Endoprosthesis in the Treatment of Thoracic Aortic Diseases for Non-Surgical Candidates under the Physician Sponsored IDE. PURPOSE OF RESEARCH: You are invited to participate in a research study for treatment of aneurysms of the descending thoracic aorta. The investigational device, called the TAG Thoracic Endoprosthesis (device) has been designed to simplify treatment of aneurysms of the descending thoracic aorta. The other pathologies treated can include pseudoaneurysms, acute and chronic dissections, penetrating ulcers, mycotic aneurysms, ruptures, fistulae, and transections.The device is made from a graft (an artificial vessel) which is surrounded on the outside by a metal mesh-like form. The device is in the shape of a tube. The device reinforces the weakened part of the aorta from the inside. Blood flows through the device to the arteries that go to your abdomen and legs. The device is folded tightly onto a catheter (a flexible, hollow tube) that is put into the aorta through an artery in your leg. Unless there is a problem, you would not need to have your chest opened.

    Stanford is currently not accepting patients for this trial. For more information, please contact Archana Verma, (650) 736 - 0959.

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  • Impact of C-arm CT in Decreased Renal Function Undergoing TACE for Tx of Hepato-Cellular Carcinoma Not Recruiting

    Impact on contrast dose or total volume of contrast required to effectively treat the targeted tumor.

    Stanford is currently not accepting patients for this trial. For more information, please contact Kamil Unver, (650) 725 - 9810.

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  • Imaging During Surgery in Diagnosing Patients With Prostate, Bladder, or Kidney Cancer Not Recruiting

    This pilot clinical trial studies imaging during surgery in diagnosing patients with prostate, bladder, or kidney cancer. New diagnostic imaging procedures, may find prostate, bladder, or kidney cancer

    Stanford is currently not accepting patients for this trial. For more information, please contact Mark Gonzalgo, 650-725-5544.

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  • Pulmonary Interstitial Lymphography in Early Stage Lung Cancer Not Recruiting

    Non-small cell lung cancer (NSCLC) is the most deadly cancer in the world. NSCLC annually causes 150,000 deaths in the US and greater than 1 million worldwide. The standard treatment for early stage NSCLC is lobectomy with lymphadenectomy. However, many patients are poor operative candidates or decline surgery. An emerging alternative is Stereotactic Body Radiation Therapy (SBRT). Mounting evidence from Phase I/II studies demonstrates that SBRT offers excellent local control. Most SBRT trials focused on small, peripheral tumors in inoperable patients. Increasingly, clinical trials study SBRT in operable patients, often with larger, central tumors. Using clinical staging, a significant proportion of patients harbor occult nodal metastases when undergoing SBRT to the primary tumor alone. Subgroups of patients carry even higher risk of nodal metastases. These nodal metastases frequently would be removed by surgical intervention. However, SBRT, at present, is only directed at the primary tumor, potentially leading to regional failures in otherwise curable patients. To increase the effectiveness of SBRT for lung tumors, the next logical step is to explore whether the highest risk areas of disease spread can be identified and targeted. Regional failure could be reduced and outcome improved in a significant proportion of patients treated with SBRT if the primary nodal drainage (PND) were identified, targeted and treated in addition to the primary tumor. We propose to conduct a study to determine how well water soluble iodinated contrast material when injected directly into the tumor can be visualized on CT scan and integrated into radiation therapy treatment planning.

    Stanford is currently not accepting patients for this trial. For more information, please contact Laura Gable, (650) 736 - 0798.

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  • HepaSphere/Quadrasphere Microspheres for Delivery of Doxorubicin for the Treatment of Hepatocellular Cancer Recruiting

    The purpose of this study is to evaluate overall survival in patients treated with HepaSphere/QuadraSphere compared to conventional transarterial chemoembolization with particle PVA.

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  • Perfusion CT as a Predictor of Treatment Response in Patients With Hepatic Malignancies Recruiting

    The purpose of this study is to determine whether baseline CT perfusion characteristics (measurements of blood-flow using CT) of hepatic cancers can predict tumor response to treatment and whether perfusion CT after treatment can be used as a biomarker for response to treatment. Treatment may consist of chemotherapy or stereotactic body radiotherapy (SBRT)or embolization therapy.

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  • ExAblate Conformal Bone System Treatment of Metastatic Bone Tumors for the Palliation of Pain Recruiting

    A study to evaluate the safety and initial effectiveness of the ExAblate 2100 Conformal Bone System in the treatment of pain resulting from metastatic bone tumors.

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Teaching

2013-14 Courses


Publications

Journal Articles


  • Prophylactic Topically Applied Ice to Prevent Cutaneous Complications of Nontarget Chemoembolization and Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Wang, D. S., Louie, J. D., Kothary, N., Shah, R. P., Sze, D. Y. 2013; 24 (4): 596-600

    Abstract

    Cutaneous complications can result from nontarget deposition during transcatheter arterial chemoembolization or radioembolization. Liver tu"TACE" because of its inconsistent use in the literature (ie, to abbreviate different terms). Please note that "TACE" has been replaced with "transcatheter arterial chemoembolization" or simply "chemoembolization" as appropriate throughout the manuscript. Please verify these changes.-->mors may receive blood supply from parasitized extrahepatic arteries (EHAs) that also perfuse skin or from hepatic arteries located near the origin of the falciform artery (FA), which perfuses the anterior abdominal wall. To vasoconstrict cutaneous vasculature and prevent nontarget deposition, ice packs were topically applied to at-risk skin in nine chemoembolization treatments performed via 14 parasitized EHAs, seven chemoembolization treatments near the FA origin, and five radioembolization treatments in cases in which the FA could not be prophylactically coil-embolized. No postprocedural cutaneous complications were encountered.

    View details for DOI 10.1016/j.jvir.2012.12.020

    View details for Web of Science ID 000316828000022

    View details for PubMedID 23522163

  • Migration of implanted markers for image-guided lung tumor stereotactic ablative radiotherapy JOURNAL OF APPLIED CLINICAL MEDICAL PHYSICS Hong, J. C., Eclov, N. C., Yu, Y., Rao, A. K., Dieterich, S., Quynh-Thu Le, Q. T., Diehn, M., Sze, D. Y., Loo, B. W., Kothary, N., Maxim, P. G. 2013; 14 (2): 77-89
  • Migration of implanted markers for image-guided lung tumor stereotactic ablative radiotherapy. Journal of applied clinical medical physics Hong, J. C., Eclov, N. C., Yu, Y., Rao, A. K., Dieterich, S., Le, Q., Diehn, M., Sze, D. Y., Loo, B. W., Kothary, N., Maxim, P. G. 2013; 14 (2): 4046-?

    Abstract

    The purpose of this study was to quantify postimplantation migration of percutaneously implanted cylindrical gold seeds ("seeds") and platinum endovascular embolization coils ("coils") for tumor tracking in pulmonary stereotactic ablative radiotherapy (SABR). We retrospectively analyzed the migration of markers in 32 consecutive patients with computed tomography scans postimplantation and at simulation. We implanted 147 markers (59 seeds, 88 coils) in or around 34 pulmonary tumors over 32 procedures, with one lesion implanted twice. Marker coordinates were rigidly aligned by minimizing fiducial registration error (FRE), the root mean square of the differences in marker locations for each tumor between scans. To also evaluate whether single markers were responsible for most migration, we aligned with and without the outlier causing the largest FRE increase per tumor. We applied the resultant transformation to all markers. We evaluated migration of individual markers and FRE of each group. Median scan interval was 8 days. Median individual marker migration was 1.28 mm (interquartile range [IQR] 0.78-2.63 mm). Median lesion FRE was 1.56 mm (IQR 0.92-2.95 mm). Outlier identification yielded 1.03 mm median migration (IQR 0.52-2.21 mm) and 1.97 mm median FRE (IQR 1.44-4.32 mm). Outliers caused a mean and median shift in the centroid of 1.22 and 0.80 mm (95th percentile 2.52 mm). Seeds and coils had no statistically significant difference. Univariate analysis suggested no correlation of migration with the number of markers, contact with the chest wall, or time elapsed. Marker migration between implantation and simulation is limited and unlikely to cause geometric miss during tracking.

    View details for DOI 10.1120/jacmp.v14i2.4046

    View details for PubMedID 23470933

  • Correlation of the Diameter of the Left Common Iliac Vein with the Risk of Lower-extremity Deep Venous Thrombosis JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Carr, S., Chan, K., Rosenberg, J., Kuo, W. T., Kothary, N., Hovsepian, D. M., Sze, D. Y., Hofmann, L. V. 2012; 23 (11): 1467-1472

    Abstract

    Compression of the left common iliac vein (CIV; LCIV) is a known risk factor for lower-extremity deep vein thrombosis (DVT). This study was performed to model the probability of DVT based on LCIV diameter and apply this to a quantitative DVT risk factor scoring system.Medical records were used to identify female patients younger than 45 years of age who were diagnosed with lower-extremity DVT (n = 21) and age-matched control subjects (n = 26) who presented to the emergency department with abdominal pain. Minimum CIV diameters were measured on computed tomography. Based on published reporting standards, 13 risk factors were scored for patients diagnosed with left-sided DVT and for control subjects. The association between vein diameter and DVT was examined by Mann-Whitney test. Odds of DVT based on vein diameter was assessed by logistic regression.Mean minimum LCIV diameters were 4.0 mm for patients with DVT and 6.5 mm for patients without DVT (P = .001). The odds of left DVT increased by a factor of 1.68 for each millimeter decrease in LCIV diameter (odds ratio = 1.68; P = .006; 95% confidence interval, 1.16-2.43). As the risk factor score increased, the relationship between diameter and risk for DVT became stronger; identical LCIV diameters were associated wtih a higher probability of developing DVT if the risk factor score was higher.Stenosis of the LCIV was found to be a strong independent risk factor for development of DVT. Moreover, each millimeter decrease in CIV diameter increased the odds of DVT by a factor of 1.68.

    View details for DOI 10.1016/j.jvir.2012.07.030

    View details for Web of Science ID 000311267900011

    View details for PubMedID 23101919

  • The diagnostic yield of CT-guided percutaneous lung biopsy in solid organ transplant recipients CLINICAL TRANSPLANTATION Hsu, J. L., Kuschner, W. G., Paik, J., Bower, N., Guillamet, M. C., Kothary, N. 2012; 26 (4): 615-621

    Abstract

    Despite the widespread use of computed tomography(CT)-guided percutaneous lung biopsy (PLB) in immunocompetent patients, the diagnostic yield and safety in solid organ transplant (SOT)recipients is unknown. The purpose of this investigation was to determine the test performance of CT-PLB in SOT recipients.We performed a 10-yr single-center, retrospective analysis among heart, lung, kidney, and liver transplant recipients. We included all adult patients who underwent a PLB of a parenchymal lung nodule following their transplantation.Within the study period, 1754 SOTs were performed, of which 45 biopsies met study criteria. Overall, the incidence of PLB in SOT was 3%.PLB established a diagnosis in 24 of 45 cases. The yield of PLB was better for combined biopsy technique (fine-needle aspiration biopsy [FNAB]) and core biopsy than for FNAB alone (odds ratio [OR]: 4.2, 95% confidence interval [CI]: 1.2, 15.6), and for lesions that were malignant (OR: 10.0, 95%CI: 1.8, 75.4) or caused by an invasive fungal infection (OR: 5.0, 95% CI:1.1, 27.9). Complications occurred in 13% (6/45) of patients.CT-guided PLB is a safe modality that provides a moderate yield for diagnosing pulmonary nodules of malignant or fungal etiology in SOT recipients.

    View details for DOI 10.1111/j.1399-0012.2011.01582.x

    View details for Web of Science ID 000307344400032

    View details for PubMedID 23050274

  • Complex Retrieval of Embedded IVC Filters: Alternative Techniques and Histologic Tissue Analysis CARDIOVASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Cupp, J. S., Louie, J. D., Kothary, N., Hofmann, L. V., Sze, D. Y., Hovsepian, D. M. 2012; 35 (3): 588-597

    Abstract

    We evaluated the safety and effectiveness of alternative endovascular methods to retrieve embedded optional and permanent filters in order to manage or reduce risk of long-term complications from implantation. Histologic tissue analysis was performed to elucidate the pathologic effects of chronic filter implantation.We studied the safety and effectiveness of alternative endovascular methods for removing embedded inferior vena cava (IVC) filters in 10 consecutive patients over 12 months. Indications for retrieval were symptomatic chronic IVC occlusion, caval and aortic perforation, and/or acute PE (pulmonary embolism) from filter-related thrombus. Retrieval was also performed to reduce risk of complications from long-term filter implantation and to eliminate the need for lifelong anticoagulation. All retrieved specimens were sent for histologic analysis.Retrieval was successful in all 10 patients. Filter types and implantation times were as follows: one Venatech (1,495 days), one Simon-Nitinol (1,485 days), one Optease (300 days), one G2 (416 days), five Günther-Tulip (GTF; mean 606 days, range 154-1,010 days), and one Celect (124 days). There were no procedural complications or adverse events at a mean follow-up of 304 days after removal (range 196-529 days). Histology revealed scant native intima surrounded by a predominance of neointimal hyperplasia and dense fibrosis in all specimens. Histologic evidence of photothermal tissue ablation was confirmed in three laser-treated specimens.Complex retrieval methods can now be used in select patients to safely remove embedded optional and permanent IVC filters previously considered irretrievable. Neointimal hyperplasia and dense fibrosis are the major components that must be separated to achieve successful retrieval of chronic filter implants.

    View details for DOI 10.1007/s00270-011-0175-1

    View details for Web of Science ID 000304162700018

    View details for PubMedID 21562933

  • Applying a Structured Innovation Process to Interventional Radiology: A Single-Center Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Sista, A. K., Hwang, G. L., Hovsepian, D. M., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Yamada, K., Hong, R., Dhanani, R., Brinton, T. J., Krummel, T. M., Makower, J., Yock, P. G., Hofmann, L. V. 2012; 23 (4): 488-494

    Abstract

    To determine the feasibility and efficacy of applying an established innovation process to an active academic interventional radiology (IR) practice.The Stanford Biodesign Medical Technology Innovation Process was used as the innovation template. Over a 4-month period, seven IR faculty and four IR fellow physicians recorded observations. These observations were converted into need statements. One particular need relating to gastrostomy tubes was diligently screened and was the subject of a single formal brainstorming session.Investigators collected 82 observations, 34 by faculty and 48 by fellows. The categories that generated the most observations were enteral feeding (n = 9, 11%), biopsy (n = 8, 10%), chest tubes (n = 6, 7%), chemoembolization and radioembolization (n = 6, 7%), and biliary interventions (n = 5, 6%). The output from the screening on the gastrostomy tube need was a specification sheet that served as a guidance document for the subsequent brainstorming session. The brainstorming session produced 10 concepts under three separate categories.This formalized innovation process generated numerous observations and ultimately 10 concepts to potentially to solve a significant clinical need, suggesting that a structured process can help guide an IR practice interested in medical innovation.

    View details for DOI 10.1016/j.jvir.2011.12.029

    View details for Web of Science ID 000302396300009

    View details for PubMedID 22464713

  • Yttrium-90 Radioembolization of Renal Cell Carcinoma Metastatic to the Liver JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Hwang, G. L., Kothary, N., Minor, D. R., Sze, D. Y. 2012; 23 (3): 323-330

    Abstract

    To investigate the safety and efficacy of yttrium-90 ((90)Y) hepatic radioembolization treatment of patients with liver-dominant metastatic renal cell carcinoma (RCC) refractory to immunotherapy and targeted therapies.Between March 2006 and December 2010, six patients with metastatic RCC underwent eight radioembolization treatments with (90)Y-labeled resin microspheres for unresectable liver-dominant metastases. All six patients had previous hepatic tumor progression despite targeted therapies or immunotherapies. All had bilobar disease and required whole-liver treatment. Clinical and biochemical toxicities were recorded, and tumor response was assessed every 2-3 months after treatment by cross-sectional imaging.The median dose delivered was 1.89 Gbq (range 0.41-2.03 Gbq). Grade 1 and 2 toxicities were noted in all patients, primarily fatigue. Follow-up imaging was available for five patients. In follow-up periods from 2-64 months (mean 25 months), three patients showed complete responses, and 1 patient showed a partial response by standard imaging criteria, and these patients are alive at 64 months, 55 months, 17 months, and 7 months after treatment. Two patients with rapid progression of disease died within 2 months of treatment, although hepatic malignancy or failure was not the cause of death in either patient.(90)Y radioembolization is a promising option for liver-dominant metastatic RCC with potential for providing long-term survival in patients refractory to or intolerant of targeted therapies.

    View details for DOI 10.1016/j.jvir.2011.11.007

    View details for Web of Science ID 000301328100007

    View details for PubMedID 22277275

  • Percutaneous Cholecystostomy for Acute Cholecystitis: Ten-Year Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Joseph, T., Unver, K., Hwang, G. L., Rosenberg, J., Sze, D. Y., Hashimi, S., Kothary, N., Louie, J. D., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M. 2012; 23 (1): 83-88

    Abstract

    To review the clinical course of patients with acute cholecystitis treated by percutaneous cholecystostomy, and to identify risk factors retrospectively that predict outcome.A total of 106 patients diagnosed with acute cholecystitis were treated by percutaneous cholecystostomy during a 10-year period. Seventy-one (67%) presented to the emergency department (ED) specifically for acute cholecystitis, and 35 (23%) were inpatients previously admitted for other conditions. Outcomes of the two groups were compared with respect to severity of illness, leukocytosis, bile culture, liver function tests, imaging features, time intervals from onset of symptoms to medical and percutaneous intervention, and whether surgical cholecystectomy was later performed.Overall, 72 patients (68%) showed an improvement clinically, whereas 34 (32%) showed no improvement or a clinically worsened condition after cholecystostomy. Patients who presented to the ED primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P < .0001). Gallstones were identified in 54% of patients who presented to the ED, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P < .0001). Bacterial bile cultures were analyzed in 95% of patients and showed positive results in 52%, with no overall effect on outcome. There was no correlation between the time of onset of symptoms until antibiotic therapy or cholecystostomy in either group. Long-term outcomes for both groups were better for those who later underwent cholecystectomy (P < .0001).Outcomes after percutaneous cholecystostomy for acute cholecystitis are better when the disease is primary and not precipitated by concurrent illness.

    View details for DOI 10.1016/j.jvir.2011.09.030

    View details for Web of Science ID 000299151400015

    View details for PubMedID 22133709

  • Imaging Guidance with C-arm CT: Prospective Evaluation of Its Impact on Patient Radiation Exposure during Transhepatic Arterial Chemoembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Abdelmaksoud, M. H., Tognolini, A., Fahrig, R., Rosenberg, J., Hovsepian, D. M., Ganguly, A., Louie, J. D., Kuo, W. T., Hwang, G. L., Holzer, A., Sze, D. Y., Hofmann, L. V. 2011; 22 (11): 1535-1544

    Abstract

    To prospectively evaluate the impact of C-arm CT on radiation exposure to hepatocellular carcinoma (HCC) patients treated by chemoembolization.Patients with HCC (N = 87) underwent digital subtraction angiography (DSA; control group) or combined C-arm CT/DSA (test group) for chemoembolization. Dose-area product (DAP) and cumulative dose (CD) were measured for guidance and treatment verification. Contrast agent volume and C-arm CT utility were also measured.The marginal DAP increase in the test group was offset by a substantial (50%) decrease in CD from DSA. Use of C-arm CT allowed reduction of DAP and CD from DSA imaging (P = .007 and P = .017). Experienced operators were more efficient in substituting C-arm CT for DSA, resulting in a negligible increase (7.5%) in total DAP for guidance, compared with an increase of 34% for all operators (P = .03). For treatment verification, DAP from C-arm CT exceeded that from DSA, approaching that of conventional CT. The test group used less contrast medium (P = .001), and C-arm CT provided critical or supplemental information in 20% and 17% of patients, respectively.Routine use of C-arm CT can increase stochastic risk (DAP) but decrease deterministic risk (CD) from DSA. However, the increase in DAP is operator-dependent, thus, with experience, it can be reduced to under 10%. C-arm CT provides information not provided by DSA in 33% of patients, while decreasing the use of iodinated contrast medium. As with all radiation-emitting modalities, C-arm CT should be used judiciously.

    View details for DOI 10.1016/j.jvir.2011.07.008

    View details for Web of Science ID 000296661800008

    View details for PubMedID 21875814

  • Embolization of Parasitized Extrahepatic Arteries to Reestablish Intrahepatic Arterial Supply to Tumors before Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1355-1362

    Abstract

    To perform embolization of parasitized extrahepatic arteries (EHAs) before radioembolization to reestablish intrahepatic arterial supply to large, peripheral tumors, and to evaluate the technical and clinical outcomes of this intervention.Among 201 patients retrospectively analyzed, embolization of 73 parasitized EHAs in 35 patients was performed. Most embolization procedures were performed during preparatory angiography using large particles and coils. Digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy were used to evaluate the immediate perfusion via intrahepatic collateral channels of target tumor areas previously supplied by parasitized EHAs. Follow-up imaging of differential regional tumor response was used to evaluate microsphere distribution and clinical outcome.After embolization, reestablishment of intrahepatic arterial supply was confirmed by both DSA and C-arm CT in 94% of territories and by scintigraphy in 96%. In 32% of patients, the differential response of treatment could not be evaluated because of uniform disease progression. However, symmetric regional tumor response in 94% of evaluable patients indicated successful delivery of microspheres to the territories previously supplied by parasitized EHAs.Reestablishment of intrahepatic arterial inflow to hepatic tumors by embolization of parasitized EHAs is safe and effective and results in successful delivery of yttrium-90 microspheres to tumors previously perfused by parasitized EHAs.

    View details for DOI 10.1016/j.jvir.2011.06.007

    View details for Web of Science ID 000295708400002

    View details for PubMedID 21961979

  • In Vitro Design and Characterization of the Nonviral Gene Delivery Vector lopamidol, Protamine, Ethiodized Oil Reagent JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Higgins, L. J., Hwang, G. L., Rosenberg, J., Katzenberg, R. H., Kothary, N., Sze, D. Y., Hofmann, L. V. 2011; 22 (10): 1457-1463

    Abstract

    To demonstrate cellular selectivity toward hepatoma cells and compare the efficiency of gene delivery of a novel nonviral vector of iopamidol, protamine, and ethiodized oil reagents (VIPER).Rat hepatocellular carcinoma (HCC) cells were transfected in triplicate under varying conditions by using firefly luciferase as a reporter gene. Conditions included variations of a protamine:DNA (P:D) complex (20:1, 50:1, 100:1, 200:1 mass ratios), iopamidol (0%, 10%, 33%), and ethiodized oil (0%, 1%, 2%, 4%, 8%, and 16%). The conditions affording efficient gene transfer and ease of translation to in vivo studies were selected for cell line comparison (HCC cells vs hepatocytes). Adenoviral transduction was compared with nonviral vector transfection.At low concentrations, ethiodized oil increased transfection efficiency regardless of P:D mass ratio. However, high concentrations resulted in significant attenuation. Unexpectedly, the addition of iopamidol to P:D complexes markedly improved transfection efficiency. When using an optimal P:D, iopamidol, and ethiodized oil solution, DNA transfection of normal liver and tumor cells showed significant selectivity for tumor cells. In the context of hepatoma cells, transfection efficiency with the nonviral vector was better than 10(4) pfu adenovirus.The development and characterization of the VIPER system provides a possible alternative to viral gene therapy of HCC.

    View details for DOI 10.1016/j.jvir.2011.06.025

    View details for Web of Science ID 000295708400018

    View details for PubMedID 21856173

  • Consolidation of Hepatic Arterial Inflow by Embolization of Variant Hepatic Arteries in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Louie, J. D., Kothary, N., Hwang, G. L., Kuo, W. T., Hofmann, L. V., Hovsepian, D. M., Sze, D. Y. 2011; 22 (10): 1364-1372

    Abstract

    Before yttrium-90 ((90)Y) radioembolization administration, the authors consolidated arterial inflow by embolizing variant hepatic arteries (HAs) to make microsphere delivery simpler and safer. The present study reviews the technical and clinical success of these consolidation procedures.Preparatory and treatment angiograms were retrospectively analyzed for 201 patients. Variant HAs were coil-embolized during preparatory angiography to simplify arterial anatomy. Collateral arterial perfusion of territories previously supplied by variant HAs was evaluated by digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) scintigraphy, and by follow-up evaluation of regional tumor response.A total of 47 variant HAs were embolized in 43 patients. After embolization of variant HAs, cross-perfusion into the embolized territory was depicted by DSA and by C-arm CT in 100% of patients and by (99m)Tc-MAA scintigraphy in 92.7%. Uniform progressive disease prevented evaluation in 33% of patients, but regional tumor response in patients who responded supported successful delivery of microspheres to the embolized territories in 95.5% of evaluable patients.Embolization of variant HAs for consolidation of hepatic supply in preparation for (90)Y radioembolization promotes treatment of affected territories via intrahepatic collateral channels.

    View details for DOI 10.1016/j.jvir.2011.06.014

    View details for Web of Science ID 000295708400004

    View details for PubMedID 21961981

  • HIGH RETENTION AND SAFETY OF PERCUTANEOUSLY IMPLANTED ENDOVASCULAR EMBOLIZATION COILS AS FIDUCIAL MARKERS FOR IMAGE-GUIDED STEREOTACTIC ABLATIVE RADIOTHERAPY OF PULMONARY TUMORS INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS Hong, J. C., Yu, Y., Rao, A. K., Ditererich, S., Maxim, P. G., Le, Q., Diehn, M., Sze, D. Y., Kothary, N., Loo, B. W. 2011; 81 (1): 85-90

    Abstract

    To compare the retention rates of two types of implanted fiducial markers for stereotactic ablative radiotherapy (SABR) of pulmonary tumors, smooth cylindrical gold "seed" markers ("seeds") and platinum endovascular embolization coils ("coils"), and to compare the complication rates associated with the respective implantation procedures.We retrospectively analyzed the retention of percutaneously implanted markers in 54 consecutive patients between January 2004 and June 2009. A total of 270 markers (129 seeds, 141 coils) were implanted in or around 60 pulmonary tumors over 59 procedures. Markers were implanted using a percutaneous approach under computed tomography (CT) guidance. Postimplantation and follow-up imaging studies were analyzed to score marker retention relative to the number of markers implanted. Markers remaining near the tumor were scored as retained. Markers in a distant location (e.g., pleural space) were scored as lost. CT imaging artifacts near markers were quantified on radiation therapy planning scans.Immediately after implantation, 140 of 141 coils (99.3%) were retained, compared to 110 of 129 seeds (85.3%); the difference was highly significant (p<0.0001). Of the total number of lost markers, 45% were reported lost during implantation, but 55% were lost immediately afterwards. No additional markers were lost on longer-term follow-up. Implanted lesions were peripherally located for both seeds (mean distance, 0.33 cm from pleural surface) and coils (0.34 cm) (p=0.96). Incidences of all pneumothorax (including asymptomatic) and pneumothorax requiring chest tube placement were lower in implantation of coils (23% and 3%, respectively) vs. seeds (54% and 29%, respectively; p=0.02 and 0.01). The degree of CT artifact was similar between marker types.Retention of CT-guided percutaneously implanted coils is significantly better than that of seed markers. Furthermore, implanting coils is at least as safe as implanting seeds. Using coils should permit implantation of fewer markers and require fewer repeat implantation procedures owing to lost markers.

    View details for DOI 10.1016/j.ijrobp.2010.04.037

    View details for Web of Science ID 000294093300012

    View details for PubMedID 20675070

  • Photothermal Ablation with the Excimer Laser Sheath Technique for Embedded Inferior Vena Cava Filter Removal: Initial Results from a Prospective Study JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kuo, W. T., Odegaard, J. I., Louie, J. D., Sze, D. Y., Unver, K., Kothary, N., Rosenberg, J. K., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (6): 813-823

    Abstract

    To evaluate the safety and effectiveness of the excimer laser sheath technique for removing embedded inferior vena cava (IVC) filters.Over 12 months, 25 consecutive patients undergoing attempted IVC filter retrieval with a laser-assisted sheath technique were prospectively enrolled into an institutional review board-approved study registry. There were 10 men and 15 women (mean age 50 years, range 20-76 years); 18 (72%) of 25 patients were referred from an outside hospital. Indications for retrieval included symptomatic filter-related acute caval thrombosis (with or without acute pulmonary embolism), chronic IVC occlusion, and bowel penetration. Retrieval was also performed to remove risks from prolonged implantation and potentially to eliminate need for lifelong anticoagulation. After failure of standard methods, controlled photothermal ablation of filter-adherent tissue with a Spectranetics laser sheath and CVX-300 laser system was performed. All patients were evaluated with cavography, and specimens were sent for histologic analysis.Laser-assisted retrieval was successful in 24 (96%) of 25 patients as follows: 11 Günther Tulip (mean 375 days, range 127-882 days), 4 Celect (mean 387 days, range 332-440 days), 2 Option (mean 215 days, range 100-330 days), 4 OPTEASE (mean 387 days, range 71-749 days; 1 failed 188 days), 2 TRAPEASE (mean 871 days, range 187-1,555 days), and 2 Greenfield (mean 12.8 years, range 7.2-18.3 years). There was one (4%) major complication (acute thrombus, treated with thrombolysis), three (12%) minor complications (small extravasation, self-limited), and one adverse event (coagulopathic retroperitoneal hemorrhage) at follow-up (mean 126 days, range 13-302 days). Photothermal ablation of filter-adherent tissue was histologically confirmed in 23 (92%) of 25 patients.The laser-assisted sheath technique appears to be a safe and effective tool for retrieving embedded IVC filters, including permanent types, with implantation ranging from months to > 18 years.

    View details for DOI 10.1016/j.jvir.2011.01.459

    View details for Web of Science ID 000291414500011

    View details for PubMedID 21530309

  • Common Iliac Vein Stenosis and Risk of Symptomatic Pulmonary Embolism: An Inverse Correlation JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Chan, K. T., Popat, R. A., Sze, D. Y., Kuo, W. T., Kothary, N., Louie, J. D., Hovsepian, D. M., Hwang, G. L., Hofmann, L. V. 2011; 22 (2): 133-141

    Abstract

    To test the hypothesis that a common iliac vein (CIV) stenosis may impair embolization of a large deep venous thrombosis (DVT) to the lungs, decreasing the incidence of a symptomatic pulmonary embolism (PE).Between January 2002 and August 2007, 75 patients diagnosed with unilateral DVT were included in a single-institution case-control study. Minimum CIV diameters were measured 1 cm below the inferior vena cava (IVC) bifurcation on computed tomography (CT) images. A significant stenosis in the CIV ipsilateral to the DVT was defined as having either a diameter 4 mm or less or a greater than 70% reduction in lumen diameter. A symptomatic PE was defined as having symptoms and imaging findings consistent with a PE. The odds of symptomatic PE versus CIV stenosis were assessed using logistic regression models. The associations between thrombus location, stenosis, and symptomatic PE were assessed using a stratified analysis.Of 75 subjects, 49 (65%) presented with symptomatic PE. There were 17 (23%) subjects with a venous lumen 4 mm or less and 12 (16%) subjects with a greater than 70% stenosis. CIV stenosis of 4 mm or less resulted in a decreased odds of a symptomatic PE compared with a lumen greater than 4 mm (odds ratio [OR] 0.17, P = .011), whereas a greater than 70% stenosis increased the odds of DVT involving the CIV (OR 7.1, P = .047).Among patients with unilateral DVT, those with an ipsilateral CIV lumen of 4 mm or less have an 83% lower risk of developing symptomatic PE compared with patients with a CIV lumen greater than 4 mm.

    View details for DOI 10.1016/j.jvir.2010.10.009

    View details for Web of Science ID 000287166600004

    View details for PubMedID 21276911

  • C-arm Computed Tomography for Hepatic Interventions: A Practical Guide JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Tognolini, A., Louie, J., Hwang, G., Hofmann, L., Sze, D., Kothary, N. 2010; 21 (12): 1817-1823

    Abstract

    With adoption of catheter-based techniques that require technically difficult catheterization, the need for imaging platforms that exploit the advantages of multiple modalities and offer three-dimensional visualization has correspondingly increased. At the authors' institution, C-arm computed tomography (CT) is routinely used to complement conventional digital subtraction angiography for transcatheter therapy. The goal of the present report is to share experience with the use of C-arm CT in hepatic interventions, with the aim to provide practical tips for optimizing image acquisition and postprocessing. Although the authors' direct experience is limited to the equipment of a single manufacturer, many of the principles and guidelines can be readily extrapolated to other C-arm CT systems.

    View details for DOI 10.1016/j.jvir.2010.07.027

    View details for Web of Science ID 000285372600003

    View details for PubMedID 20970354

  • Renewing Focus on Resident Education: Increased Responsibility and Ownership in Interventional Radiology Rotations Improves the Educational Experience JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Ghatan, C. E., Hwang, G. L., Kuo, W. T., Louie, J. D., Sze, D. Y., Hovsepian, D. M., Desser, T. S., Hofmann, L. V. 2010; 21 (11): 1697-1702

    Abstract

    To enhance the educational experience among residents rotating through interventional radiology (IR) by encouraging ownership and responsibility.In May 2006, the authors implemented changes in resident education in IR that included increased clinical responsibilities, structured didactics, and greater hands-on experience, including call. Residents were assigned as first assistants, ownership of cases was encouraged, and assignment to a week on the consult service was instituted to help residents better understand all aspects of IR practice. Additional faculty recruitment and program expansion ensured the same high level of training for the fellowship program. Evaluations were reviewed every year (July 1, 2007-June 30, 2009) for hands-on training, daily teaching, didactic conferences, and overall effectiveness of the clinical service. A graduated scale of 1-5 was used.In 2009, 3 years after the curricular changes were made, the quality of hands-on training, daily case reviews and consults, didactics, and overall education had markedly improved with 89%, 71%, 65%, and 82% of the residents rating these respective aspects of the training as "above expectations" (4 on a scale of 5) or "superior" (5 on a scale of 5) compared with 77%, 23%, 20%, and 60% in 2005-2006. Three years after the changes, the impact of these changes on recruitment patterns also showed improvement, with 28.6% of the class of 2010 pursuing a fellowship in IR.Increasing resident ownership, responsibility, and hands-on experience improves resident education in IR, which, in turn, promotes interest in the field.

    View details for DOI 10.1016/j.jvir.2010.07.009

    View details for Web of Science ID 000284244200009

    View details for PubMedID 20884234

  • Development of New Hepaticoenteric Collateral Pathways after Hepatic Arterial Skeletonization in Preparation for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Abdelmaksoud, M. H., Hwang, G. L., Louie, J. D., Kothary, N., Hofmann, L. V., Kuo, W. T., Hovsepian, D. M., Sze, D. Y. 2010; 21 (9): 1385-1395

    Abstract

    Development of new hepaticoenteric anastomotic vessels may occur after endovascular skeletonization of the hepatic artery. Left untreated, they can serve as pathways for nontarget radioembolization. The authors reviewed the incidence, anatomy, management, and significance of collateral vessel formation in patients undergoing radioembolization.One hundred thirty-eight treatments performed on 122 patients were reviewed. Each patient underwent a preparatory digital subtraction angiogram (DSA) and embolization of all hepaticoenteric vessels in preparation for yttrium-90 ((90)Y) administration. Successful skeletonization was verified by C-arm computed tomography (CACT) and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy. During the subsequent treatment session, DSA and CACT were repeated before administration of (90)Y, and the detection of extrahepatic perfusion prompted additional embolization.Forty-two patients (34.4%) undergoing 43 treatments (31.2%) required adjunctive embolization of hepaticoenteric vessels immediately before (90)Y administration. Previous scintigraphy findings showed extrahepatic perfusion in only three cases (7.1%). Vessels were identified by DSA in 54.1%, by CACT in 4.9%, or required both in 41.0%. The time interval between angiograms did not correlate with risk of requiring reembolization (P = .297). A total of 19.7% of vessels were new collateral vessels not visible during the initial angiography. Despite reembolization, three patients (7.1%) had gastric or duodenal ulceration, compared with 1.3% who never had visible collateral vessels, all of whom underwent whole-liver treatment with resin microspheres (P = .038).Development of collateral hepaticoenteric anastomoses occurs after endovascular skeletonization of the hepatic artery. Identified vessels may be managed by adjunctive embolization, but patients appear to remain at increased risk for gastrointestinal complications.

    View details for DOI 10.1016/j.jvir.2010.04.030

    View details for Web of Science ID 000281620600012

    View details for PubMedID 20688531

  • Computed Tomography-Guided Percutaneous Needle Biopsy of Indeterminate Pulmonary Pathology: Efficacy of Obtaining a Diagnostic Sample in Immunocompetent and Immunocompromised Patients CLINICAL LUNG CANCER Kothary, N., Bartos, J. A., Hwang, G. L., Dua, R., Kuo, W. T., Hofmann, L. V. 2010; 11 (4): 251-256

    Abstract

    We aimed to evaluate the efficacy of computed tomography (CT)-guided percutaneous lung biopsy of pulmonary nodules with indeterminate radiologic characteristics in patients at risk for malignant and nonmalignant processes such as infection or inflammation.From January 2003 to September 2008, 262 patients (mean age, 59 years; range, 18-92 years) with pulmonary nodules or a mass of uncertain etiology and with indeterminate radiologic characteristics underwent CT-guided percutaneous lung biopsy. Patients with discordant clinical history and imaging findings or immunocompromised patients at risk for both etiologies were included. Specimens were submitted for both cytology and microbiology.Of the entire cohort, 166 patients (63.4%) had a nonmalignant process, and 96 patients (36.6%) had a malignancy. CT-guided percutaneous lung biopsy established a diagnosis in 166 patients (63.4%). Of the 166 patients with a nonmalignant etiology and 96 patients with malignancy, it provided a definitive diagnosis in 91 patients (54.8%) and 75 patients (78.1%), respectively, a difference that was statistically significant (P = .0001). Overall diagnostic efficacy between immunocompetent and immunocompromised patients was comparable (P = .2); however, detection of infection or inflammation in individual groups was lower compared with detection of malignancy (P = .002 and P = .06, respectively).CT-guided percutaneous lung biopsy in patients who are clinically at risk for both nonmalignant and malignant processes continues to be a challenge. Although CT-guided percutaneous biopsy can establish an accurate diagnosis in a large majority of patients with malignancy, it is significantly less sensitive for infectious or inflammatory processes.

    View details for DOI 10.3816/CLC.2010.n.032

    View details for Web of Science ID 000279496400006

    View details for PubMedID 20630827

  • Utility of C-arm CT in Patients with Hepatocellular Carcinoma undergoing Transhepatic Arterial Chemoembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Tognolini, A., Louie, J. D., Hwang, G. L., Hofmann, L. V., Sze, D. Y., Kothary, N. 2010; 21 (3): 339-347

    Abstract

    To evaluate the utility of C-arm computed tomography (CT) on treatment algorithms in patients undergoing transhepatic arterial chemoembolization for hepatocellular carcinoma (HCC).From March 2008 to July 2008, 84 consecutive patients with HCC underwent 100 consecutive transhepatic arterial chemoembolizations with iodized oil. Unenhanced and iodinated contrast medium-enhanced C-arm CT with planar and three-dimensional imaging were performed in addition to conventional digital subtraction angiography (DSA) in all patients. The effect on diagnosis and treatment was determined by testing the hypotheses that C-arm CT, in comparison to DSA, provides (a) improved lesion detection, (b) expedient identification and mapping of arterial supply to a tumor, (c) improved characterization of a lesion to allow confident differentiation of HCC from pseudolesions such as arterioportal shunts, and (d) an improved evaluation of treatment completeness. The effect of C-arm CT was analyzed on the basis of information provided with C-arm CT that was not provided or readily apparent at DSA.C-arm CT was technically successful in 93 of the 100 procedures (93%). C-arm CT provided information not apparent or discernible at DSA in 30 of the 84 patients (36%) and resulted in a change in diagnosis, treatment planning, or treatment delivery in 24 (28%). The additional information included, amongst others, visualization of additional or angiographically occult tumors in 13 of the 84 patients (15%) and identification of incomplete treatment in six (7.1%).C-arm CT is a useful collaborative tool in patients undergoing transhepatic arterial chemoembolization and can affect patient care in more than one-fourth of patients.

    View details for DOI 10.1016/j.jvir.2009.11.007

    View details for Web of Science ID 000277367700005

    View details for PubMedID 20133156

  • A Primer on Image-guided Radiation Therapy for the Interventional Radiologist JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Dieterich, S., Louie, J. D., Koong, A. C., Hofmann, L. V., Sze, D. Y. 2009; 20 (7): 859-862

    Abstract

    The use of image-guided radiation therapy in thoracic and abdominal tumors is increasing. Herein, the authors review the process of image-guided radiation therapy and describe techniques useful for optimal implantation of fiducial markers.

    View details for DOI 10.1016/j.jvir.2009.03.037

    View details for Web of Science ID 000267613000001

    View details for PubMedID 19481470

  • Incorporating Cone-beam CT into the Treatment Planning for Yttrium-90 Radioembolization JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Louie, J. D., Kothary, N., Kuo, W. T., Hwang, G. L., Hofmann, L. V., Goris, M. L., Iagaru, A. H., Sze, D. Y. 2009; 20 (5): 606-613

    Abstract

    To prepare for yttrium-90 ((90)Y) microsphere radioembolization therapy, digital subtraction angiography (DSA) and technetium- 99m-labeled macroaggregated albumin ((99m)Tc MAA) scintigraphy are used for treatment planning and detection of potential nontarget embolization. The present study was performed to determine if cone-beam computed tomography (CBCT) affects treatment planning as an adjunct to these conventional imaging modalities.From March 2007 to August 2008, 42 consecutive patients (21 men, 21 women; mean age, 59 years; range, 21-75 y) who underwent radioembolization were evaluated by CBCT in addition to DSA and (99m)Tc MAA scintigraphy during treatment planning, and their records were retrospectively reviewed. The contrast-enhanced territories shown by CBCT with selective intraarterial contrast agent administration were used to predict intrahepatic and possible extrahepatic distribution of microspheres.In 22 of 42 cases (52%), extrahepatic enhancement or incomplete tumor perfusion seen on CBCT affected the treatment plan. In 14 patients (33%), the findings were evident exclusively on CBCT and not detected by DSA. When comparing CBCT versus (99m)Tc MAA scintigraphy, CBCT showed eight cases of extrahepatic enhancement (19%) that were not evident on (99m)Tc MAA imaging. CBCT findings directed the additional embolization of vessels or repositioning of the catheter for better contrast agent and microsphere distribution. One case of gastric ulcer from nontarget embolization caused by reader error was observed.CBCT can provide additional information about tumor and tissue perfusion not currently detectable by DSA or (99m)Tc MAA imaging, which should optimize (90)Y microsphere delivery and reduce nontarget embolization.

    View details for DOI 10.1016/j.jvir.2009.01.021

    View details for Web of Science ID 000265700900007

    View details for PubMedID 19345589

  • Percutaneous Implantation of Fiducial Markers for Imaging-Guided Radiation Therapy AMERICAN JOURNAL OF ROENTGENOLOGY Kothary, N., Dieterich, S., Louie, J. D., Chang, D. T., Hofmann, L. V., Sze, D. Y. 2009; 192 (4): 1090-1096

    Abstract

    The use of imaging-guided radiation therapy (IGRT) to treat thoracic and abdominal tumors is increasing. In this article, we review the process of IGRT and describe techniques to implant fiducial markers in the optimal geometry.Implantation of fiducial markers can be challenging. A better understanding of the physics of IGRT can help optimize fiducial marker placement for precise tumor targeting.

    View details for DOI 10.2214/AJR.08.1399

    View details for Web of Science ID 000264358900038

    View details for PubMedID 19304719

  • Safety and Efficacy of Percutaneous Fiducial Marker Implantation for Image-guided Radiation Therapy JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Heit, J. J., Louie, J. D., Kuo, W. T., Loo, B. W., Koong, A., Chang, D. T., Hovsepian, D., Sze, D. Y., Hofmann, L. V. 2009; 20 (2): 235-239

    Abstract

    To evaluate the safety and technical success rate of percutaneous fiducial marker implantation in preparation for image-guided radiation therapy.From January 2003 to January 2008, we retrospectively reviewed 139 percutaneous fiducial marker implantations in 132 patients. Of the 139 implantations, 44 were in the lung, 61 were in the pancreas, and 34 were in the liver. Procedure-related major and minor complications were documented. Technical success was defined as implantation enabling adequate treatment planning and computed tomographic simulation.The major and minor complication rates were 5% and 17.3%, respectively. Pneumothorax after lung implantation was the most common complication. Pneumothoraces were seen in 20 of the 44 lung implantations (45%); a chest tube was required in only seven of the 44 lung transplantations (16%). Of the 139 implantations, 133 were successful; in six implantations (4.3%) the fiducial markers migrated and required additional procedures or alternate methods of implantation.Percutaneous implantation of fiducial marker is a safe and effective procedure with risks that are similar to those of conventional percutaneous organ biopsy.

    View details for DOI 10.1016/j.jvir.2008.09.026

    View details for Web of Science ID 000263075000012

    View details for PubMedID 19019700

  • Radiologic Monitoring of Hepatocellular Carcinoma Tumor Viability after Transhepatic Arterial Chemoembolization: Estimating the Accuracy of Contrast-enhanced Cross-sectional Imaging with Histopathologic Correlation JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Hunt, S. J., Yu, W., Weintraub, J., Prince, M. R., Kothary, N. 2009; 20 (1): 30-38

    Abstract

    Cross-sectional diagnostic imaging studies such as contrast-enhanced quadruple-phase helical computed tomography (CT) and contrast-enhanced magnetic resonance (MR) imaging are routinely performed to evaluate tumor response to transhepatic arterial chemoembolization. However, the true correlation between imaging characteristics and histopathologic tumor viability is not known. The aim of the present retrospective study was to determine the sensitivity and specificity of contrast-enhanced CT and contrast-enhanced MR imaging with use of histopathologic analysis.Between February 2002 and October 2005, a total of 31 patients (age, 51-74 years; mean, 60 y) who had undergone chemoembolization underwent follow-up diagnostic cross-sectional imaging before transplantation. The mean time interval between the imaging study and transplantation was 32 days (range, 1-117 d). Imaging studies were assessed for residual or recurrent tumor and were then correlated to the findings of histopathologic analysis performed on the surgical specimens at the time of transplantation.The overall sensitivity and specificity rates of cross-sectional imaging studies were 35% and 64%, respectively. The overall accuracy rate of CT was 43%, with 36% sensitivity and 57% specificity. The overall accuracy rate of MR imaging was 55%, with 43% sensitivity and 75% specificity. Gross macroscopic disease was missed in one patient (9%) who underwent MR imaging and four patients (19%) who underwent CT.Contrast-enhanced CT and MR imaging after chemoembolization are associated with high error rates. Between the two modalities, MR has higher sensitivity and specificity and may be a preferable imaging tool for patients who have undergone chemoembolization.

    View details for DOI 10.1016/j.jvir.2008.09.034

    View details for Web of Science ID 000262426400006

    View details for PubMedID 19028117

  • Catheter-directed embolectomy, fragmentation, and thrombolysis for the treatment of massive pulmonary embolism after failure of systemic thrombolysis CHEST Kuo, W. T., Van den Bosch, M. A., Hofmann, L. V., Louie, J. D., Kothary, N., Sze, D. Y. 2008; 134 (2): 250-254

    Abstract

    The standard medical management for patients in extremis from massive pulmonary embolism (PE) is systemic thrombolysis, but the utility of this treatment relative to catheter-directed intervention (CDI) is unknown. We evaluated the effectiveness of CDI as part of a treatment algorithm for life-threatening PE.A retrospective review was performed on 70 consecutive patients with suspected acute PE over a 10-year period (from 1997 to 2006) who had been referred for pulmonary angiography and/or intervention. The criteria for study inclusion were patients who received CDI due to angiographically confirmed massive PE and hemodynamic shock (shock index, > or = 0.9). CDI involved suction embolectomy and fragmentation with or without catheter thrombolysis.Twelve patients were treated with CDI. There were seven men and five women (mean age, 56 years; age range, 21 to 80 years). Seven patients (58%) were referred for CDI after failing systemic infusion with 100 mg of tissue plasminogen activator, and five patients (42%) had contraindications to systemic thrombolysis. Catheter-directed fragmentation and embolectomy were performed in all patients (100%). Additionally, catheter-guided thrombolysis was performed in eight patients (67%). Technical success was achieved in 12 of 12 cases (100%). There were no major procedural complications (0%). Significant hemodynamic improvement (shock index, < 0.9) was observed in 10 of 12 cases (83%). The remaining two patients (17%) died secondary to cardiac arrest within 24 h. Ten of 12 patients (83%) survived and remained stable until hospital discharge (mean duration, 20 days; range, 3 to 51 days).In the setting of hemodynamic shock from massive PE, CDI is potentially a life-saving treatment for patients who have not responded to or cannot tolerate systemic thrombolysis.

    View details for DOI 10.1378/chest.07-2846

    View details for Web of Science ID 000258492500008

    View details for PubMedID 18682455

  • Complications of ablative therapies in lung cancer CLINICAL LUNG CANCER Padda, S., Kothary, N., Donington, J., Cannon, W., Loo, B. W., Kee, S., Wakelee, H. 2008; 9 (2): 122-126

    Abstract

    Two cases of complications secondary to the use of microwave ablation (MWA) in non-small-cell lung cancer (NSCLC) are discussed herein. The first case involves a 62-year-old man with stage IB NSCLC who declined surgery and pursued MWA. Within 7 months, he had residual disease at the MWA treatment site, and surgery was performed. The patient was found to have pleural and chest wall involvement, making complete resection impossible. The second case involves an 86-year-old woman with a second local recurrence of NSCLC and previous treatment including surgery and chemoradiation therapy. She was initially a surgical candidate but declined surgery and pursued MWA. Within 6 months, she had residual disease at the MWA treatment site. A second MWA was performed, and she developed a large cavitary abscess at the MWA site and had subsequent clinical decline. Less invasive ablation therapies and stereotactic radiosurgery are being developed for patients with inoperable lung cancer. Because these modalities have recently been developed, trials that clearly show efficacy and survival benefit are yet to be completed. Ablation procedures can result in complications, including residual disease and cavitary lesions susceptible to infection. These cases highlight the caution that should still be observed when recommending lung ablation strategies and the importance of selecting appropriate patients.

    View details for Web of Science ID 000255039000010

    View details for PubMedID 18501100

  • Transarterial chemoembolization for primary hepatocellular carcinoma in patients at high risk JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kothary, N., Weintraub, J. L., Susman, J., Rundback, J. H. 2007; 18 (12): 1517-1526

    Abstract

    Transarterial chemoembolization (TACE) has become a standard treatment option for patients with unresectable hepatocellular carcinoma (HCC). This retrospective study evaluated the safety and efficacy of TACE in patients at high risk with increased serum bilirubin level, low serum albumin level, poor hepatic reserve, or compromised hepatopetal flow in the portal vein (PV).A total of 52 patients underwent 65 high-risk procedures. Thirty patients treated with 38 procedures (57.7% of patients and 58.5% of procedures) had serum bilirubin levels of 2-3 mg/dL (ie, moderate elevation) and 22 patients treated with 27 procedures (42.3% and 41.5%) had a serum bilirubin level of at least 3 mg/dL (ie, considerable elevation). Forty patients (76.9%) had serum albumin levels less than 3.5 mg/dL. Thirteen recipients of 15 procedures (25% and 20%) had portal diversion or obstruction. Twenty-four patients (46.2%) had a Child-Pugh (CP) score of 8 or less and 28 patients (53.8%) had a CP score of at least 9 at the time of TACE. Thirty patients (57.7%) had focal tumors and 22 patients (42.3%) had multifocal or infiltrative disease. Superselective chemoembolization could be performed in 37 procedures (56.9%); lobar chemoembolization was performed in the remaining 28 (43.1%).The 30-day mortality rate was 7.7% and the procedure-related morbidity rate was 10.8%. Patients with multifocal disease and lobar embolization had significantly higher mortality rates (P=.03). Individual factors such as serum bilirubin, serum albumin, and PV flow did not affect outcomes significantly. The 1- and 2-year survival rates in patients with focal disease were 67.9% and 37.7%, respectively, compared with 19.6% and 0% in patients with multifocal disease (P<.0001).TACE in patients considered at high risk does not necessarily incur a higher incidence of morbidity or mortality. Patient selection should be based on extent of disease, and these tumors should be treated selectively at a segmental level if possible.

    View details for DOI 10.1016/j.jvir.2007.07.035

    View details for Web of Science ID 000251654600008

    View details for PubMedID 18057286

  • A novel endovascular adjustable polytetrafluoroethylene-covered stent for the management of hepatic encephalopathy after transjugular intrahepatic portosystemic shunt JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Weintraub, J. L., Mobley, D. G., Weiss, M. E., Swanson, E., Kothary, N. 2007; 18 (4): 563-566

    Abstract

    Transjugular intrahepatic portosystemic shunt (TIPS) is frequently complicated by hepatic encephalopathy. When medical therapy fails, TIPS narrowing and resultant increase in the portosystemic pressure gradient and blood flow to the liver is performed in order to reverse the encephalopathy. We present a method for reducing the TIPS using a polytetrafluoroethylene-covered balloon expandable stent placed over a self-expanding stent. This results in a narrowed TIPS that not only rapidly increases the portosystemic gradient but also can be adjusted by dilating the balloon expandable stent. This method was successful in narrowing the patient's TIPS, acutely increasing the portosystemic gradient and reversing the hepatic encephalopathy.

    View details for DOI 10.1016/j.jvir.2007.02.004

    View details for Web of Science ID 000246008400012

    View details for PubMedID 17446548

Conference Proceedings


  • Common iliac vein stenosis: a risk factor for oral contraceptive-induced deep vein thrombosis Chan, K. T., Tye, G. A., Popat, R. A., Kuo, W. T., Unver, K., Kothary, N., Sze, D. Y., Hofmann, L. V. MOSBY-ELSEVIER. 2011

    Abstract

    The objective of the study was to determine whether women with significant left common iliac vein stenosis who also use combined oral contraceptives (COCs) have a combined likelihood of deep vein thrombosis (DVT) greater than each independent risk.This was a case-control study comparing 35 women with DVT against 35 age-matched controls. Common iliac vein diameters were measured from computed tomography and magnetic resonance imaging. Logistic regression modeling was used with adjustment for risk factors.DVT was associated with COC use (P = .022) and with increasing degrees of common iliac vein stenosis (P = .004). Compared with women without venous stenosis or COC use, the odds of DVT in women with a 70% venous stenosis who also use COCs was associated with a 17-fold increase (P = .01).Venous stenosis and COC use are independent risk factors for DVT. Women concurrently exposed to both have a multiplicative effect resulting in an increased risk of DVT. We recommend further studies to investigate this effect and its potential clinical implications.

    View details for DOI 10.1016/j.ajog.2011.06.100

    View details for Web of Science ID 000297329200019

    View details for PubMedID 21893308

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