Faculty Bibliography

PURPOSE/OBJECTIVE:To assess the safety and feasibility of Pulsed Electrical Fields (PEF) ablation in various organs and patient populations. MATERIALS AND METHODS/METHODS:This multi-center, retrospective study collected data from five academic medical centers on patients undergoing percutaneous PEF ablation, with a minimum of 30 days follow-up. Parameters assessed included demographics, treatment specifics, immediate adverse events, and survival rates. Procedures used CT or ultrasound guidance with a 19-gauge insulated needle and PEF probe. RESULTS:This study included 155 patients with a mean age of 60.7 years, predominantly with lung cancer (77/155). Most patients 85 % (131/155) had stage IV disease. The mean hospital stay post PEF was 0.3 days, with most discharged the same day. In lung procedures adverse events of pneumothorax occurred in 21.5 % of lung procedures, with 11.3 % requiring chest tube placements. No adverse events were observed in liver procedures. The 1-year overall survival rate for the entire cohort was 74.6 %, with patients with colorectal cancer having the highest survival rate of 89.7 %, and patient with sarcomas lowest at 18.0 %. CONCLUSION/CONCLUSIONS:Percutaneous PEF is feasible to be performed across a variety of organs. Although difficult to compare with other modalities, this data suggests that PEF ablation is relatively safe. However, further prospective studies with larger sample sizes and comprehensive imaging are needed to confirm these findings and establish efficacy.

BACKGROUND:Histotripsy is a novel, noninvasive, nonionizing, and nonthermal approach that uses focused ultrasound waves to treat liver tumors. This technology received a de novo Food and Drug Administration grant in late 2023. This study aimed to provide the first report on post-trial real-world clinical safety data. METHODS:Safety outcomes within 30 days of histotripsy were collected after obtaining Food and Drug Administration clearance (December 22, 2023 to July 26, 2024). All centers that performed histotripsy were invited to participate in this study. Complications requiring treatment were graded using the Clavien-Dindo classification and Comprehensive Complication Index (CCI). RESULTS:A total of 295 patients underwent histotripsy for 510 tumors at 18 centers. The treated liver tumor types included colorectal metastases (n = 140), neuroendocrine tumors (n = 46), hepatocellular carcinomas (n = 31), pancreatic tumors (n = 30), and breast metastases (n = 26). The most common numbers of tumors treated per procedure were 1 (n = 170), 2 (n = 69), and 3 (n = 37). All 8 liver segments were treated for tumors. Safety data were available for 230 patients from 9 centers. Of note, 12 of 230 patients (5.2%) experienced complications of any grade. Most patients (9 [75%]) had minor cases (Clavien-Dindo grade ≤ II). The median and mean CCIs were 0.00 (IQR, 0.00-0.00) and 0.00 (95% CI, 0.00-0.75). All 3 major complications (Clavien-Dindo grade > II [1.3%]) were death due to disease progression. All 3 patients underwent histotripsy with palliative intent for known advanced intra- and extrahepatic diseases. CONCLUSION/CONCLUSIONS:To the best of our knowledge, this is the first study to report on the real-world therapeutic use of histotripsy for liver tumors. Histotripsy was well tolerated, with few overall complications and rare serious complications, indicating a safety profile that compares favorably with that of other liver-directed and surgical therapies for the treatment of liver tumors. Long-term follow-up data, including oncologic outcomes, were collected.

BACKGROUND/UNASSIGNED:Mitomycin-C is an older drug which has a synergistic mechanism of action with irinotecan. This study evaluated the outcomes of selective intra-arterial mitomycin-C infusions in combination with bi-weekly systemic irinotecan for treatment of liver-dominant metastatic colorectal cancer (CRC) which progressed after hepatic arterial infusion (HAI) pump chemotherapy with floxuridine and at least two lines of systemic chemotherapy. METHODS/UNASSIGNED:An IRB-approved retrospective review of patients receiving at least two sessions of selective monthly mitomycin-C infusions in interventional radiology (IR) was performed. Anatomic and metabolic imaging was initially obtained at 4 weeks after the second infusion, and every 2-3 months thereafter. Response was evaluated according to Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and European Organization for Research and Treatment of Cancer (EORTC) criteria. Patient, disease and procedural parameters were recorded. Progression-free survival (PFS), liver progression-free survival (LPFS) and overall survival (OS) were assessed with Kaplan Meier methodology. RESULTS/UNASSIGNED:mutations and 35/46 (76.1%) had extrahepatic disease at the time of the first infusion. On initial follow-up, liver disease control was observed in 38/46 using RECIST 1.1 (82.6%; partial response 13%, stable disease 69.6%) and 26/31 using EORTC criteria (83.9%; complete response 6.5%, partial response 48.4%, stable disease 29%). Median PFS, LPFS and OS were 4.1 [95% confidence interval (CI): 3.2-4.9], 5.5 (95% CI: 2.5-8.4) and 9.6 (95% CI: 8.2-11.1) months respectively. The infusions were discontinued in 26 (56.5%) patients due to disease progression. Eighteen patients (39.1%) discontinued the infusion protocol due to toxicities/complications, including hepatic/biliary toxicity (26.1%), hepatic arterial thrombosis (15.2%) and/or pulmonary toxicity (8.7%). CONCLUSIONS/UNASSIGNED:In this heavily pretreated population, addition of intra-arterial mitomycin-C was associated with initial liver disease control rates exceeding 80%. Toxicities were observed, particularly in patients with prolonged disease control who received ≥4 infusions.

PURPOSE:To evaluate the safety, primary patency, and clinical outcomes of hepatic artery stent graft (SG) placement for vascular injuries. MATERIALS AND METHODS:Patients treated with hepatic arterial SG placement for vascular injuries between September 2018 and September 2021 were reviewed. Data on demographic characteristics, indication, stent graft characteristics, antiplatelet/anticoagulant use, clinical success rate, complications, and type of follow-up imaging were collected. Follow-up images were reviewed by 2 independent reviewers to assess primary patency. A time-to-event analysis was performed. The median duration of stent graft patency was estimated using Kaplan-Meier curves. A Cox proportional hazard model was used to evaluate factors related to stent graft patency. RESULTS:Thirty-five patients were treated with hepatic arterial SG placement, 11 for postoperative bleeds and 24 for hepatic artery infusion pump catheter-related complications. Clinical success was achieved in 32 (91%) patients (95% CI, 77-98). The median primary patency was 87 days (95% CI, 73-293). Stent grafts of ≥6-mm diameter retained patency for a longer duration than that with stent grafts of smaller diameters (6 mm vs 5 mm; hazard ratio, 0.35; 95% CI, 0.14-0.88; P = .026; and 7+ mm vs 5 mm; hazard ratio, 0.27; 95% CI, 0.09-0.83; P = .023). Anticoagulation/antiplatelet regimen was not associated with increased stent graft patency duration (P > .05). Only minor complications were reported in 2 (5.7%) patients. CONCLUSIONS:Stent grafts can be used safely and effectively to treat injuries of the hepatic artery. Stent graft diameters of ≥6 mm seem to provide more durable patency.

BACKGROUND:Real-time split-dose PET can identify the targeted colorectal liver metastasis (CLM) and eliminate the need for repeated contrast administration before and during thermal ablation (TA). This study aimed to assess the added value of pre-ablation real-time split-dose PET when combined with non-contract CT in the detection of CLM for ablation and the evaluation of the ablation zone and margins. METHODS:A total of 190 CLMs/125 participants from two IRB-approved prospective clinical trials using PET/CT-guided TA were analyzed. Based on detection on pre-TA imaging, CLMs were categorized as detectable, non-detectable, and of poor conspicuity on CT alone, and detectable, non-detectable, and low FDG-avidity on PET/CT after the initial dose. Ablation margins around the targeted CLM were evaluated using a 3D volumetric approach. RESULTS:We found that 129/190 (67.9%) CLMs were detectable on CT alone, and 61/190 CLMs (32.1%) were undetectable or of poor conspicuity, not allowing accurate depiction and targeting by CT alone. Thus, the theoretical 5- and 10-mm margins could not be defined in these tumors (32.1%) using CT alone. When TA intraprocedural PET/CT images are obtained and inspected (fused PET/CT), only 4 CLM (2.1%) remained undetectable or had a low FDG avidity. CONCLUSIONS:The addition of PET to non-contrast CT improved CLM detection for ablation targeting, margin assessments, and continuous depiction of the FDG avid CLMs during the ablation without the need for multiple intravenous contrast injections pre- and intra-procedurally.

PURPOSE/OBJECTIVE:To evaluate a transmission optical spectroscopy instrument for rapid ex vivo assessment of core needle cancer biopsies (CNBs) at the point of care. MATERIALS AND METHODS/METHODS:CNBs from surgically resected renal tumors and nontumor regions were scanned on their sampling trays with a custom spectroscopy instrument. After extracting principal spectral components, machine learning was used to train logistic regression, support vector machines, and random decision forest (RF) classifiers on 80% of randomized and stratified data. The algorithms were evaluated on the remaining 20% of the data set held out during training. Binary classification (tumor/nontumor) was performed based on a decision threshold. Multinomial classification was also performed to differentiate between the subtypes of renal cell carcinoma (RCC) and account for potential confounding effects from fat, blood, and necrotic tissue. Classifiers were compared based on sensitivity, specificity, and positive predictive value (PPV) relative to a histopathologic standard. RESULTS:A total of 545 CNBs from 102 patients were analyzed, yielding 5,583 spectra after outlier exclusion. At the individual spectra level, the best performing algorithm was RF with sensitivities of 96% and 92% and specificities of 90% and 89%, for the binary and multiclass analyses, respectively. At the full CNB level, RF algorithm also showed the highest sensitivity and specificity (93% and 91%, respectively). For RCC subtypes, the highest sensitivity and PPV were attained for clear cell (93.5%) and chromophobe (98.2%) subtypes, respectively. CONCLUSIONS:Ex vivo spectroscopy imaging paired with machine learning can accurately characterize renal mass CNB at the time of tissue acquisition.

Barcelona clinic liver cancer (BCLC) intermediate stage hepatocellular carcinoma is a heterogenous disease. Transarterial chemoembolization is offered as the first line therapy in this disease stage. Recent advances in systemic therapy have markedly improved outcomes even in advanced stage disease. The use of systemic therapy in BCLC intermediate stage disease may now be of therapeutic benefit in selected patients. We will focus on "the up to seven" criteria and its utility in selecting systemic therapy.

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.