Stent Graft Placement for the Treatment of Hepatic Artery Injury in Patients with Cancer: Primary Patency and Clinical Outcomes.

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.

Real-Time Split-Dose PET/CT-Guided Ablation Improves Colorectal Liver Metastasis Detection and Ablation Zone Margin Assessments without the Need for Repeated Contrast Injection.

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.

Up to seven criteria in selection of systemic therapy for hepatocellular carcinoma.

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.

Evaluation of an Integrated Spectroscopy and Classification Platform for Point-of-Care Core Needle Biopsy Assessment: Performance Characteristics from Ex Vivo Renal Mass Biopsies.

PURPOSE: 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: 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.

Temporal and geospatial variations among the interventional radiology physician workforce in the United States.

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: 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.

Safety and Efficacy of Arterially Directed Liver Therapies in the Treatment of Hepatic Metastatic Ovarian Cancer: A Retrospective Single-Institution Study.

PURPOSE: To evaluate the safety and efficacy of 2 locoregional therapies (LRTs) including hepatic artery embolization (HAE) and transarterial radioembolization (TARE) in the treatment of patients with metastatic ovarian cancer to the liver. MATERIAL AND METHODS: From October 2010 to May 2019, the data of 15 consecutive patients (median age, 54 years ± 9.8; range, 35-78 years) with hepatic metastatic ovarian cancer who were treated with either HAE (n = 6; 40%) or TARE (n = 9; 60%) were reviewed. The most common histopathologic type was epithelial ovarian carcinoma (80%). The most common chemotherapy regimens used prior to embolization included carboplatin, paclitaxel, cisplatin, and bevacizumab. Patients received a mean of 4 lines ± 3 (range, 1-9) of chemotherapy. All patients with serous carcinoma were resistant to platinum at the time of embolization. Indications for embolization were progression of disease to the liver while receiving chemotherapy in 14 (93.3%) patients and palliative pain control in 1 patient. RESULTS: The overall response rates at 1, 3, and 6 months were 92.4%, 85.6%, and 70%, respectively. Median overall survival from the time of LRT was 9 (95% confidence interval [CI], 4-14) months. Median local tumor progression was 6.4 months ± 5.03 (95% CI, 3.3-9.5). No grade 3-5 adverse events were detected in either group. CONCLUSIONS: HAE and TARE were well tolerated in patients with metastatic ovarian cancer to the liver and possibly ensured prolonged disease control in heavily treated, predominantly in patients resistant to platinum. Larger numbers are needed to verify these data.

Prospective Evaluation of Unprocessed Core Needle Biopsy DNA and RNA Yield from Lung, Liver, and Kidney Tumors: Implications for Cancer Genomics.

CONTEXT: 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: 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: Median tumor DNA yields from all 18G and 20G samples were 5880 ng and 2710 ng, respectively. Median tumor RNA yields from all 18G and 20G samples were 1100 ng and 230 ng, respectively. A wide range of DNA and RNA quantities (1060-13,390 ng and 370-6280 ng, respectively) were acquired. Median DNA and RNA yields from 18G needles were significantly greater than those from 20G needles across all organs (p < 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.

Acute and delayed bleeding requiring embolization after image-guided liver biopsy in patients with cancer.

PURPOSE: 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: 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: 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.

Feasibility of a Modified Biopsy Needle for Irreversible Electroporation Ablation and Periprocedural Tissue Sampling.

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: Simulation-suggested ablations with experimental probes were smaller than that with standard electrodes (455.23 vs 543.16 mm2), although both exhibited similar shape. Computed tomography (standard: 556 ± 61 mm2, experimental: 515 ± 67 mm2; P = .25) and histology (standard: 313 ± 77 mm2, experimental: 275 ± 75 mm2; 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.

Feasibility of catheter-directed intraluminal irreversible electroporation of porcine ureter and acute outcomes in response to increasing energy delivery.

PURPOSE: 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: 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.

Depletion of Core Needle Biopsy Cellularity and DNA Content as a Result of Vigorous Touch Preparations.

CONTEXT: 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: 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.

The impact of genetic heterogeneity on biomarker development in kidney cancer assessed by multiregional sampling.

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.

The state of irreversible electroporation in interventional oncology.

A new ablation modality, irreversible electroporation (IRE), has been of increasing interest in interventional radiology. Its nonthermal mechanism of action of killing tumor cells allows physicians the ability to ablate tumors in areas previously contraindicated for thermal ablation. This article reviews the current published clinical outcomes, imaging follow-up, and the current knowledge gaps in the procedure for patients treated with IRE.

Radiofrequency ablation of T1 lung carcinoma: comparison of outcomes for first primary, metachronous, and synchronous lung tumors.

PURPOSE: To report and compare outcomes after radiofrequency ablation for treatment-naïve 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-naïve 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-naïve T1 lung tumors, including patients with metachronous and synchronous tumors.

Percutaneous ablation of peribiliary tumors with irreversible electroporation.

PURPOSE: To assess biliary complications after irreversible electroporation (IRE) ablation of hepatic tumors located < 1 cm from major bile ducts. MATERIALS AND METHODS: A retrospective review was conducted of all percutaneous IRE ablations of hepatic tumors within 1 cm of the common, left, or right hepatic ducts at a single institution from January 2011 to September 2012. Computed tomography imaging performed before and after treatment was examined for evidence of bile duct dilatation, stricture, or leakage. Serum bilirubin and alkaline phosphatase levels were analyzed for evidence of biliary injury. RESULTS: There were 22 hepatic metastases in 11 patients with at least one tumor within 1 cm of the common, left, or right hepatic duct that were treated with IRE ablations in 15 sessions. Median tumor size treated was 3.0 cm (mean, 2.8 cm ± 1.2, range, 1.0-4.7 cm). Laboratory values obtained after IRE were considered abnormal after four treatment sessions in three patients (bilirubin, 2.6-17.6 mg/dL; alkaline phosphatase, 130-1,035 U/L); these abnormal values were transient in two sessions. Two patients had prolonged elevation of values, and one required stent placement; both of these conditions appeared to be secondary to tumor progression rather than bile duct injury. CONCLUSIONS: This clinical experience suggests that IRE may be a treatment option for centrally located liver tumors with margins adjacent to major bile ducts where thermal ablation techniques are contraindicated. Further studies with extended follow-up periods are necessary to establish the safety profile of IRE in this setting.