Faculty Bibliography

OBJECTIVE:To analyze the temporal trends and state-wide geospatial variations in Vascular and Interventional Radiology (VIR) workforce in the United States. METHODS:The State Physician Workforce Data from the AAMC website was accessed for years 2015, 2017, and 2019. The variables collected for each state included total number of active physicians, total number of physicians per specialty and total number of female physicians in VIR. Comparative data was obtained for vascular surgery (VS), diagnostic radiology (DR), and radiation oncology (RO). The annual growth rate for total physicians and sub-analysis of female physicians in each state was computed for each specialty. RESULTS:From 2015 to 2019, the total number of active physicians in the United States grew by 1.8% per year. Growth of active physicians in VIR grew by 8.3%, DR 0.06%, VS 4.4%, and RO 1.9% per year. Colorado and Minnesota had the highest growth rate for VIR physicians (15%). VIR physicians per 100,000 people increased from 0.84 (2015) to 1.10 (2019) in the US. In comparison, VS physicians increased from 0.99 (2015) to 1.14 (2019), DR physicians decreased from 8.61 (2015) to 8.43 (2019), and RO physicians grew from 1.48 (2015) to 1.56 (2019). Women represented 6.8% of the VIR workforce in the US in 2019 and increased by a rate of 16% annually in the US from 2015 to 2019. In comparison, the number of women in VS has grown by 21%, DR by 2%, and RO by 2.4% during the same period. The state of Maryland has the highest proportion of women in VIR at 18%. CONCLUSION/CONCLUSIONS:The number of VIR physicians is increasing at a higher rate than the national overall physician growth, and while female VIR physicians makeup a small fraction of the VIR workforce, their numbers have increased at a faster rate than overall VIR physicians.

PURPOSE/OBJECTIVE:To evaluate the safety and efficacy of two locoregional therapies (LRT) including hepatic artery embolization (HAE) and transarterial radioembolization (TARE) in treating patients with metastatic ovarian cancer to the liver. METHODS:From October 2010 to May 2019, the data of 15 consecutive patients (median age, 54 ± 9.8; range, 35-78) with hepatic metastatic ovarian cancer that were treated with either HAE (n = 6, 40%) or TARE (n = 9, 60%) were reviewed. Most common histopathologic type was epithelial ovarian carcinoma (80%). Most common chemotherapy regimens used prior to embolization included carboplatin, paclitaxel, cisplatin, and bevacizumab. Patients received a mean of 4 ± 3 (range 1-9) lines of chemotherapy. All patients with serous carcinoma were platinum-resistant at the time of embolization. Indications for embolization were progression of disease in the liver while receiving chemotherapy in 14 (93.3%) and palliative pain control in 1 patient. RESULTS:Overall response rate at 1, 3, and 6 months was 92.4%, 85.6%, and 70%. The median overall survival from the time of LRT was 9 months (95% confidence interval [CI], 4-14 months). Median local tumor progression was 6.4 ± 5.03 months (95% CI, 3.3-9.5). No grade 3-5 adverse events were detected in either group. CONCLUSION/CONCLUSIONS:HAE and TARE were well tolerated in patients with metastatic ovarian cancer to the liver and possibly prolong disease control in heavily treated, predominately platinum-resistant patients. Larger numbers are needed to verify these data.

CONTEXT/BACKGROUND:Targeted needle biopsies are increasingly performed for the genetic characterization of cancer. While the nucleic acid content of core needle biopsies after standard pathology processing (i.e., formalin fixation and paraffin embedding (FFPE)) has been previously reported, little is known about the potential yield for molecular analysis at the time of biopsy sample acquisition. OBJECTIVES/OBJECTIVE:Our objective was to improve the understanding of DNA and RNA yields from commonly used core needle biopsy techniques prior to sample processing. METHODS:We performed 552 ex vivo 18 and 20G core biopsies in the lungs, liver, and kidneys. DNA and RNA were extracted from fresh-frozen core samples and quantified for statistical comparisons based on needle gauge, biopsy site, and tissue type. RESULTS:< 0.001). CONCLUSIONS:Core needle biopsy techniques for cancer diagnostics yield a broad range of DNA and RNA for molecular pathology, though quantities are greater than what has been reported for FFPE processed material. Since non-formalin-fixed DNA is advantageous for molecular studies, workflows that optimize core needle biopsy yield for molecular characterization should be explored.

OBJECTIVES:To test the feasibility of modified biopsy needles as probes for irreversible electroporation ablation and periprocedural biopsy. METHODS:Core biopsy needles of 16-G/9-cm were customized to serve as experimental ablation probes. Computed tomography-guided percutaneous irreversible electroporation was performed in in vivo porcine kidneys with pairs of experimental (n = 10) or standard probes (n = 10) using a single parameter set (1667 V/cm, ninety 100 µs pulses). Two biopsy samples were taken immediately following ablation using the experimental probes (n = 20). Ablation outcomes were compared using computed tomography, simulation, and histology. Biopsy and necropsy histology were compared. RESULTS:; P = .29) indicated ablations with experimental probes were not significantly different from the standard. Histopathology indicated similar morphological changes in both groups. Biopsies from the ablation zone yielded at least 1 core with sufficient tissue for analysis (11 of the 20). CONCLUSIONS:A combined probe for irreversible electroporation ablation and periprocedural tissue sampling from the ablation zone is feasible. Ablation outcomes are comparable to those of standard electrodes.

PURPOSE/OBJECTIVE:To report incidence of acute versus delayed presentations of bleeding requiring embolization after focal liver biopsy, in correlation with angiographic findings and treatment success rates. The available literature will be reviewed as well. MATERIALS AND METHODS/METHODS:Health Insurance Portability and Accountability Act-compliant institutional review board approved retrospective review of 2180 consecutive patients undergoing 2335 targeted liver biopsies at a tertiary-care cancer center. Hepatic arterial embolization episodes within 30days from biopsy were identified via radiology PACS. Electronic medical record review was performed for indication of embolization and postembolization clinical course. RESULTS:The incidence of postbiopsy bleeding requiring embolization was 0.5% (12/2335 biopsies). In those with bleeding, 1/12 (8%) had no hepatic arterial findings at angiography. Angiographic hepatic arterial findings resolved after embolization in 11/11 patients (100% technical success). Bleeding ceased after embolization in 10/12 patients (83% clinical success). Complications were seen in 2/12 (17%) patients: cholecystitis and hepatic infarct, respectively. Delayed presentation of bleeding (defined as >24h postbiopsy) occurred in 5/12 (42%) patients; the longest latency was 12days. CONCLUSION/CONCLUSIONS:The overall incidence of bleeding requiring embolization in our population was 0.5%. This complication rate compares favorably to the 0-4.2% (median: 0.29%) rate quoted in the available, heterogeneous, literature on this topic. Delayed presentation occurred in almost half of patients. Arterial embolization carries excellent technical and clinical success rates.

CONTEXT/BACKGROUND:Touch preparations (TP) of core needle biopsies (CNBs) are used at some institutions for on-site assessment of CNB adequacy. In our clinical practice, we have encountered instances in which TPs resulted in substantial depletion of CNB cellularity. OBJECTIVE:To examine the effect of increasingly vigorous TPs on cellularity and DNA content of CNBs. DESIGN/METHODS:Ex vivo CNBs (n = 56) were performed on resected lung and kidney tumor specimens. For each specimen, CNBs were performed in quadruplicate on tumor and nontumor tissue and subjected to 1 of 4 TP methods: imprint, 1-cm drag, 2-cm drag, or full-slide drag. Overall cellularity in TPs relative to corresponding CNBs was estimated semiquantitatively. DNA was extracted and quantified from 12 TPs and corresponding CNBs. Two cytopathologists performed a blinded diagnostic assessment of Diff-Quik-stained TPs. RESULTS:Cellularity of imprint, 1-cm, 2-cm, and full-slide TPs represented, on average, 19%, 33%, 41%, and 46% of total CNB cellularity, respectively (p = .003). Average DNA content in imprint, 1-cm, and 2-cm TPs was 0.3 μg (range, 0.1-0.8 μg), 0.4 μg (range, 0.1-1 μg), and 0.6 μg (range, 0.2-1.3 μg), respectively, which represented on average 15%, 36%, and 50%, respectively, of total CNB DNA content. Diagnostic accuracy was not inferior for less-extensive TPs, compared with more-extensive TPs. CONCLUSIONS:Vigorous TPs may contain a substantial fraction of CNB cellularity and DNA content, whereas more-limited TPs are less disruptive to CNBs but remain suitable for cytologic assessment. We suggest avoiding excessively forceful TPs and, whenever clinically feasible, obtaining additional samples to ensure sufficient cellularity for potential ancillary studies.

PURPOSE/OBJECTIVE:To evaluate the feasibility of focal intraluminal irreversible electroporation (IRE) in the ureter with a novel electrode catheter and to study the treatment effects in response to increasing pulse strength. MATERIALS AND METHODS/METHODS:Five IRE treatment settings were each evaluated twice for the ablation of normal ureter in 5 Yorkshire pigs (n = 1-4 ablations per animal; total of 10 ablations) with the use of a prototype device under ultrasound and fluoroscopic guidance. Animals received unilateral or bilateral treatment, limited to a maximum of 2 ablations in any 1 ureter. Treatment was delivered with increasing pulse strength (from 1,000 V to 3,000 V in increments of 500 V) while keeping the pulse duration (100 μs) and number of pulses (n = 90) constant. Ureter patency was assessed with antegrade ureteropyelography immediately following treatment. Animals were euthanized within 4 hours after treatment, and treated urinary tract was harvested for histopathologic analysis with hematoxylin and eosin and Masson trichrome stains. RESULTS:IRE was successfully performed in all animals, without evidence of ureteral perforation. Hematoxylin and eosin analysis of IRE treatments demonstrated full-thickness ablation at higher field strengths (mucosa to the adventitia). Masson trichrome stains showed preservation of connective tissue at all field strengths. CONCLUSIONS:Intraluminal catheter-directed IRE ablation is feasible and produces full-thickness ablation of normal ureters. There was no evidence of lumen perforation even at the maximum voltages evaluated.

Primary clear cell renal cell carcinoma (ccRCC) genetic heterogeneity may lead to an underestimation of the mutational burden detected from a single site evaluation. We sought to characterize the extent of clonal branching involving key tumor suppressor mutations in primary ccRCC and determine if genetic heterogeneity could limit the mutation profiling from a single region assessment. Ex vivo core needle biopsies were obtained from three to five different regions of resected renal tumors at a single institution from 2012 to 2013. DNA was extracted and targeted sequencing was performed on five genes associated with ccRCC (von-Hippel Lindau [VHL], PBRM1, SETD2, BAP1, and KDM5C). We constructed phylogenetic trees by inferring clonal evolution based on the mutations present within each core and estimated the predictive power of detecting a mutation for each successive tumor region sampled. We obtained 47 ex vivo biopsy cores from 14 primary ccRCC's (median tumor size 4.5 cm, IQR 4.0-5.9 cm). Branching patterns of various complexities were observed in tumors with three or more mutations. A VHL mutation was detected in nine tumors (64%), each time being present ubiquitously throughout the tumor. Other genes had various degrees of regional mutational variation. Based on the mutations' prevalence we estimated that three different tumor regions should be sampled to detect mutations in PBRM1, SETD2, BAP1, and/or KDM5C with 90% certainty. The mutational burden of renal tumors varies by region sampled. Single site assessment of key tumor suppressor mutations in primary ccRCC may not adequately capture the genetic predictors of tumor behavior.

PURPOSE: We sought to evaluate the safety and the diagnostic success rate of percutaneous biopsies performed under intra-procedural (18)F-deoxyglucose (FDG) positron-emission tomography/computed tomography (PET/CT) guidance for lesions difficult to see with conventional cross-sectional imaging. METHODS: From 2011 to 2013, consecutive clinically indicated percutaneous PET/CT-guided biopsies of 106 masses (mean size, 3.3 cm; range, 0.7-15.9 cm; SD, 2.9 cm) in bones (n = 33), liver (n = 26), soft tissues (n = 18), lung (n = 15) and abdomen (n = 14) were reviewed. The biopsy procedures were performed following injection of a mean of 255 MBq (SD, 74) FDG. Mean maximal standardized uptake value (SUV) of lesions was 8.8 (SD, 6.3). A systematic review of the histopathological results and outcomes was performed. RESULTS: Biopsies were positive for malignancy in 76 cases (71.7%, 76/106) and for benign tissue in 30 cases (28.3%, 30/106). Immediate results were considered adequate for 100 PET/CT biopsies (94.3%, 100/106) requiring no further exploration, and for the six others (5.7%, 6/106) benign diagnoses were confirmed after surgery (n = 4) or follow-up (n = 2). The consequent overall sensitivity and the diagnostic success of biopsy were therefore 100%. No significant differences in terms of detection of malignancy were observed between the different locations. Lesions > 2 cm or with SUV > 4 were not significantly more likely to be malignant. Complications occurred after four biopsies (3.7%, 4/106). CONCLUSION: Intra-procedural PET/CT guidance appears as a safe and effective method and allows high diagnostic success of percutaneous biopsies for metabolically active lesions.

PURPOSE: To report and compare outcomes after radiofrequency ablation for treatment-naive first primary, metachronous, and synchronous T1 lung tumors. MATERIALS AND METHODS: This institutional review board-approved retrospective study reviewed 29 patients (12 men and 17 women; median age, 73 y; age range, 55-86 y) with treatment-naive T1 lung tumors treated with radiofrequency ablation. Tumors in the 29 patients included 21 T1a and 8 T1b first primary (n = 11), metachronous (n = 14), or synchronous (n = 4) tumors (adenocarcinoma, n = 25; squamous cell carcinoma, n = 3; unspecified, n = 1). Median tumor diameter was 14 mm (range, 10-26 mm). Surveillance computed tomography or positron emission tomography-computed tomography was performed over a median period of 28 months (range, 12-83 mo). Technical success and effectiveness rates and overall and progression-free 1-year, 3-year, and 5-year survivals were calculated according to stage, first primary, metachronous, and synchronous tumor status. RESULTS: Technical success and effectiveness was 97%. Local control occurred in 17 of 21 T1a tumors (81%) and 5 of 8 T1b tumors (62.5%). The local progression rate of first primary tumors (5 of 11; 45%) was higher than that of metachronous (2 of 14; 14%; P = .07) and synchronous (0 of 4; P = .01) tumors. Estimated 1-year, 3-year, and 5-year local tumor progression-free survival was 79%, 75%, and 75%. Estimated 1-year, 3-year, and 5-year overall survival was 100%, 60%, and 14%. Survival outcomes were similar for patients with first primary, metachronous, or synchronous tumors. CONCLUSIONS: Radiofrequency ablation results in good local control and progression-free survival in patients with treatment-naive T1 lung tumors, including patients with metachronous and synchronous tumors.