Prediction of Lung Shunt Fraction for Yttrium-90 Treatment of Hepatic Tumors Using Dynamic Contrast Enhanced MRI with Quantitative Perfusion Processing.

There is no noninvasive method to estimate lung shunting fraction (LSF) in patients with liver tumors undergoing Yttrium-90 (Y90) therapy. We propose to predict LSF from noninvasive dynamic contrast enhanced (DCE) MRI using perfusion quantification. Two perfusion quantification methods were used to process DCE MRI in 25 liver tumor patients: Kety's tracer kinetic modeling with a delay-fitted global arterial input function (AIF) and quantitative transport mapping (QTM) based on the inversion of transport equation using spatial deconvolution without AIF. LSF was measured on SPECT following Tc-99m macroaggregated albumin (MAA) administration via hepatic arterial catheter. The patient cohort was partitioned into a low-risk group (LSF ≤ 10%) and a high-risk group (LSF > 10%). Results: In this patient cohort, LSF was positively correlated with QTM velocity |u| (r = 0.61, F = 14.0363, p = 0.0021), and no significant correlation was observed with Kety's parameters, tumor volume, patient age and gender. Between the low LSF and high LSF groups, there was a significant difference for QTM |u| (0.0760 ± 0.0440 vs. 0.1822 ± 0.1225 mm/s, p = 0.0011), and Kety's Ktrans (0.0401 ± 0.0360 vs 0.1198 ± 0.3048, p = 0.0471) and Ve (0.0900 ± 0.0307 vs. 0.1495 ± 0.0485, p = 0.0114). The area under the curve (AUC) for distinguishing between low LSF and high LSF was 0.87 for |u|, 0.80 for Ve and 0.74 for Ktrans. Noninvasive prediction of LSF is feasible from DCE MRI with QTM velocity postprocessing.

Safety and Efficacy of Microwave Ablation for Hepatocellular Carcinoma in the Setting of Transjugular Intrahepatic Portosystemic Shunt.

This retrospective analysis reviews five patients with transjugular intrahepatic portosystemic shunt (TIPS) who underwent percutaneous microwave ablation of hepatocellular carcinoma between January 2017 and September 2020. Mean tumor diameter was 2.0 cm (range 1.3-2.9 cm), and mean tumor distance from TIPS was 2.3 cm (range 1.5-3.3 cm). There were no major adverse events, and the TIPS patency was 100% post-ablation. The technical success rate was 100%, and the complete response rate was 100%. In this small study, percutaneous microwave ablation appears safe and effective for the treatment of hepatocellular carcinoma in patients with TIPS in the short-term follow-up period.

Role of interventional radiology in the treatment of COVID-19 patients: Early experience from an epicenter.

OBJECTIVE: To highlight the role of interventional radiology (IR) in the treatment of patients hospitalized with coronavirus disease 2019 (COVID-19). METHODS: Retrospective review of hospitalized patients who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and had one or more IR procedures at a tertiary referral hospital in New York City during a 6-week period in April and May of 2020. RESULTS: Of the 724 patients admitted with COVID-19, 92 (12.7%) underwent 124 interventional radiology procedures (79.8% in IR suite, 20.2% at bedside). The median age of IR patients was 63 years (range 24-86 years); 39.1% were female; 35.9% in the intensive care unit. The most commonly performed IR procedures were central venous catheter placement (31.5%), inferior vena cava filter placement (9.7%), angiography/embolization (4.8%), gastrostomy tube placement (9.7%), image-guided biopsy (10.5%), abscess drainage (9.7%), and cholecystostomy tube placement (6.5%). Thoracentesis/chest tube placement and nephrostomy tube placement were also performed as well as catheter-directed thrombolysis of massive pulmonary embolism and thrombectomy of deep vein thrombosis. General anesthesia (10.5%), monitored anesthesia care (18.5%), moderate sedation (29.8%), or local anesthetic (41.1%) was utilized. There were 3 (2.4%) minor complications (SIR adverse event class B), 1 (0.8%) major complication (class C), and no procedure-related death. With a median follow-up of 4.3 months, 1.1% of patients remain hospitalized, 16.3% died, and 82.6% were discharged. CONCLUSION: Interventional radiology participated in the care of hospitalized COVID-19 patients by performing a wide variety of necessary procedures.

Bone biopsy protocol for advanced prostate cancer in the era of precision medicine.

BACKGROUND: Metastatic biopsies are increasingly being performed in patients with advanced prostate cancer to search for actionable targets and/or to identify emerging resistance mechanisms. Due to a predominance of bone metastases and their sclerotic nature, obtaining sufficient tissue for clinical and genomic studies is challenging. METHODS: Patients with prostate cancer bone metastases were enrolled between February 2013 and March 2017 on an institutional review board-approved protocol for prospective image-guided bone biopsy. Bone biopsies and blood clots were collected fresh. Compact bone was subjected to formalin with a decalcifying agent for diagnosis; bone marrow and blood clots were frozen in optimum cutting temperature formulation for next-generation sequencing. Frozen slides were cut from optimum cutting temperature cryomolds and evaluated for tumor histology and purity. Tissue was macrodissected for DNA and RNA extraction, and whole-exome sequencing and RNA sequencing were performed. RESULTS: Seventy bone biopsies from 64 patients were performed. Diagnostic material confirming prostate cancer was successful in 60 of 70 cases (85.7%). The median DNA/RNA yield was 25.5 ng/µL and 16.2 ng/µL, respectively. Whole-exome sequencing was performed successfully in 49 of 60 cases (81.7%), with additional RNA sequencing performed in 20 of 60 cases (33.3%). Recurrent alterations were as expected, including those involving the AR, PTEN, TP53, BRCA2, and SPOP genes. CONCLUSIONS: This prostate cancer bone biopsy protocol ensures a valuable source for high-quality DNA and RNA for tumor sequencing and may be used to detect actionable alterations and resistance mechanisms in patients with bone metastases. Cancer 2018;124:1008-15. © 2017 American Cancer Society.

CT-Guided Fine-Needle Aspiration Biopsy of Pulmonary Nodules 8 mm or Less Has a Higher Diagnostic Accuracy than Positron Emission Tomography-CT.

PURPOSE: To compare diagnostic accuracy of CT-guided fine-needle aspiration biopsy (FNA-B) with positron emission tomography (PET)-CT for pulmonary nodules ≤ 8 mm. MATERIALS AND METHODS: A retrospective review of all CT-guided lung FNA-Bs performed between 2011 and 2014 at a single institution was undertaken to evaluate patients who had FNA-B and PET-CT imaging of nodules of ≤ 8 mm. Patients without surgical pathology or 2-year follow-up CT scans were excluded. Of 1,896 patients, 41 patients with 43 subcentimeter pulmonary nodules met study criteria. The McNemar test was used to compare FNA-B with PET-CT results. RESULTS: FNA-B had a sensitivity and diagnostic accuracy of 88.9% and 81.4%, respectively. PET-CT had an overall sensitivity and diagnostic accuracy of 38.9% and 46.5%, respectively. FNA-B had a significantly higher sensitivity and diagnostic accuracy for malignant nodules compared with PET-CT (P < .001). Pneumothorax rate after FNA-B was 13.9%, and chest tube insertion rate was 0%. CONCLUSIONS: FNA-B is a safe procedure with superior sensitivity and higher diagnostic accuracy compared with PET-CT in pulmonary nodules ≤ 8mm in size.

Decision Making in Interventional Oncology: Ablative Options in the Lung.

Image-guided ablation is safe and effective for the treatment of both primary and metastatic tumors in the lung. This article reviews the three most commonly used ablative options: radiofrequency ablation, microwave ablation, and cryoablation. We describe the advantages of each ablation modality in the lung and how to choose the most appropriate ablation device based on patient and tumor characteristics. The optimal technique for lung ablation is discussed and technical tips for improving clinical outcome are described.

Catheter-directed Intraportal Delivery of Endothelial Cell Therapy for Liver Regeneration: A Feasibility Study in a Large-Animal Model of Cirrhosis.

Purpose To demonstrate the feasibility of imaging-guided catheter-directed delivery of endothelial cell therapy in a porcine model of cirrhosis for liver regeneration. Materials and Methods After approval from the institutional animal care and use committee, autologous liver endothelial cells were grown from core hepatic specimens from swine. Cirrhosis was induced in swine by means of transcatheter infusion of ethanol and iodized oil into the hepatic artery. Three weeks after induction of cirrhosis, the swine were randomly assigned to receive autologous cell therapy (endothelial cells, n = 4) or control treatment (phosphate-buffered saline, n = 4) by means of imaging-guided transhepatic intraportal catheterization. Fluorescence-activated cell sorting analysis was performed on biopsy samples 1 hour after therapy. Three weeks after intraportal delivery of endothelial cells, the swine were euthanized and the explanted liver underwent quantitative pathologic examination. Statistical analysis was performed with an unpaired t test by using unequal variance. Results Liver endothelial cells were successfully isolated, cultured, and expanded from eight 20-mm, 18-gauge hepatic core samples to 50 × 106 autologous cells per pig. Intraportal delivery of endothelial cell therapy or saline was technically successful in all eight swine, with no complications. Endothelial cells were present in the liver for a minimum of 1 hour after intraportal infusion. Swine treated with endothelial cell therapy showed mean levels of surrogate markers of hepatobiliary injury that were consistent with decreases in hepatic fibrosis and biliary ductal damage relative to the control animals, although statistical significance was not met in this pilot study: The mean percentage of positive pixels at Masson trichrome staining was 7.28% vs 5.57%, respectively (P = .20), the mean proliferation index with cytokeratin wide-spectrum was 2.55 vs 1.13 (P = .06), and the mean proliferation index with Ki67 was 7.08 vs 4.96 (P = .14). Conclusion The results confirm the feasibility of imaging-guided catheter-directed endothelial cell therapy with an intraportal technique for the treatment of cirrhosis in a porcine model. A trend toward decreased liver fibrosis with endothelial cell therapy was observed. Larger animal studies and human studies are necessary to confirm significance. © RSNA, 2017.

Screening for hepatocellular carcinoma in high-risk populations.

Screening for hepatocellular carcinoma (HCC) should be implemented in the high-risk population. High-risk population includes patients with cirrhosis of any etiology, patients with chronic hepatitis B virus with or without cirrhosis, and patients with chronic hepatitis C virus with cirrhosis. A randomized controlled trial of over 18,000 high-risk individuals demonstrated that biannual screening reduced HCC-related mortality by 37%. The screening test of choice is ultrasound imaging with an interval of 6 months.

Pleural puncture that excludes the ablation zone decreases the risk of pneumothorax after percutaneous microwave ablation in porcine lung.

PURPOSE: To test the hypothesis that the geometry of probe placement with respect to the pleural puncture site affects the risk of pneumothorax after microwave (MW) ablation in the lung. MATERIALS AND METHODS: Computed tomography-guided MW ablation of the lung was performed in 8 swine under general anesthesia and mechanical ventilation. The orientation of the 17-gauge probe was either perpendicular (90°) or parallel (< 30°) with respect to the pleural puncture site, and the ablation power was 30 W or 65 W for 5 minutes. After MW ablation, swine were euthanized, and histopathologic changes were assessed. Frequency and factors affecting pneumothorax were evaluated by multivariate analysis. RESULTS: Among 62 lung MW ablations, 13 (21%) pneumothoraces occurred. No statistically significant difference was noted in the rate of pneumothorax between the perpendicular and the parallel orientations of the probe (31% vs 14%; odds ratio [OR], 2.8; P = .11). The pneumothorax rate was equal for 65-W and 30-W ablation powers (21% and 21%; OR, 1.0; P = .94). Under multivariate analysis, 2 factors were independent positive predictors of pneumothorax: ablation zone inclusive of pleural insertion point (OR, 7.7; P = .02) and time since intubation (hours) (OR, 2.7; P = .02). CONCLUSIONS: Geometries where the pleural puncture site excluded the ablation zone decreased pneumothorax in swine undergoing MW ablation in the lung. Treatment planning to ensure that the pleural puncture site excludes the subsequent ablation zone may reduce the rate of pneumothorax in patients undergoing MW ablation in the lung.

Distinguishing benign and life-threatening pneumatosis intestinalis in patients with cancer by CT imaging features.

OBJECTIVE: The purpose of this study is to determine the overall proportion of clinically worrisome and benign pneumatosis intestinalis (PI) occurring in patients with cancer and to evaluate associated risk factors and CT features. MATERIALS AND METHODS: We retrospectively studied the CT examinations of 84 patients treated at our tertiary cancer center. Reviewers who were blinded to clinical data and classification analyzed PI in terms of location, pattern (linear, cystic, or both), and associated CT features, including pneumoperitoneum, portomesenteric venous air, bowel wall thickening, bowel dilatation, and ascites. On the basis of the review of clinical information and criteria derived from prior literature, the cases were classified as clinically worrisome PI (underlying bowel disease) or benign PI (diagnosis of exclusion that resolved on follow-up imaging without targeted therapy). Clinical factors reviewed included age, sex, cancer type, steroid use, and chemotherapy administration. RESULTS: Forty-seven patients were classified as having benign PI (56%) and the remainder as having clinically worrisome PI (44%). The following imaging features correlated significantly with clinically worrisome PI: bowel wall thickening (p < 0.001), mesenteric stranding (p < 0.001), ascites (p < 0.001), bowel dilatation (p = 0.004), location confined to small bowel (p = 0.012), and portomesenteric venous gas (p = 0.02). Benign PI was significantly associated with PI confined to the colon (p = 0.004). CONCLUSION: Benign PI was slightly more prevalent than clinically worrisome PI in our cohort of patients with cancer. The presence of certain CT features (mesenteric stranding, bowel wall thickening, and ascites) and the location of PI may be indicators of more significant bowel disease and, therefore, of clinically worrisome cases. There was no statistical significance achieved for nonimaging clinical factors.

Alternative to surgery in early stage NSCLC-interventional radiologic approaches.

Interventional radiologists have a variety of techniques in their armamentarium to treat pulmonary tumors. While most therapies are targeted to metastasis or palliation, percutaneous thermal ablation represents a potential therapy for not only palliation, but to treat inoperable early stage disease. Although radiofrequency ablation (RFA) is the most studied of these ablative techniques, newer technologies of thermal ablation, such as microwave and cryoablation have emerged as additional options. In this article, we will review the three different thermal ablative modalities, including patient selection, technique, outcomes, complications, and imaging follow-up. A brief discussion of state of the art techniques such as irreversible electroporation (IRE) and catheter directed therapies will also be included.