Safety and Technical Feasibility of Percutaneous Renal Cryoablation of Central Tumors without Pyeloperfusion.

PURPOSE: To assess the safety and technical success of percutaneous cryoablation (PCA) without pyeloperfusion in 94 patients with central renal tumors. MATERIALS AND METHODS: A retrospective review of all central renal tumors treated by PCA without pyeloperfusion was performed. Central tumors were defined as those involving the renal sinus fat on preprocedural cross-sectional imaging. Patient demographics and baseline tumor characteristics were recorded. The details of the PCA procedure, primary and secondary technical success, rates of local recurrence, adverse events (AEs), cancer-specific survival (CSS), and overall survival (OS) were compiled. RESULTS: Ninety-four patients (48 females [51%]; mean age, 68.2 years [range, 38-87 years]) with 94 central renal tumors were included. The mean maximal tumor diameter and mean RENAL nephrometry score were 37 mm (range, 15-67 mm) and 8 (range, 4-11), respectively. Primary technical success was achieved in 94% (n = 88) of procedures. Of the patients who did not achieve primary technical success, 3 underwent successful repeat PCA (secondary technical success, 97%; n = 91/94). The other 3 patients were surveilled for residual disease. Twenty-four patients (26%) required hydrodissection during PCA. Six patients (6%) experienced major AEs after PCA including hemorrhage requiring embolization (n = 3), hemorrhage requiring transfusions with admission (n = 2), and perinephric abscess necessitating drain placement (n = 1). Twenty-two patients (23%) experienced minor AEs. Nine patients (10%) experienced local recurrence during the follow-up period. OS was 94% (n = 88/94), whereas CSS was 98% (n = 92/94) during the study follow-up period (mean, 16 months [range, 1-102 months]). CONCLUSIONS: PCA of central renal tumors appears to be safe with high rates of technical success, even without the use of pyeloperfusion.

Percutaneous Ablation of T1b Renal Cell Carcinoma: An Overview.

PURPOSE OF REVIEW: There is increasing incidence of renal cell carcinoma (RCC) with multiple treatment options currently available. The purpose of this review is to outline patient selection and technical approaches and present the current literature for percutaneous ablation of T1b (4.1-7 cm) RCC. RECENT FINDINGS: An increasing number of retrospective studies and meta-analyses have evaluated the use of percutaneous ablation for T1b RCC. Overall, these studies tend to show that percutaneous ablation in this patient population is feasible. However, rates of major adverse events and local recurrence after percutaneous ablation for T1b RCC are both higher than when ablation is used for smaller tumors. As such, a multi-disciplinary, patient-centered approach is required. Due to the increasing literature in this area, the most recent National Comprehensive Cancer Network (NCCN) guidelines include percutaneous ablation as an option for non-surgical patients with T1b RCC.

Safety and Effectiveness of Transhepatic Access for Percutaneous Renal Mass Cryoablation: A Multicenter Cohort.

PURPOSE: To establish transhepatic percutaneous cryoablation of renal masses as a safe and effective approach. MATERIALS AND METHODS: A retrospective review of records from 3 separate medical centers was performed identifying 23 patients (median age, 63 years [range 41-84 years]; 12 female [52.2%]) who underwent percutaneous transhepatic cryoablation for right-sided renal masses (median diameter, 2.4 cm [1.5-4.6 cm]) between 2008 and 2021. The median radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry score was 5 (4-10). Adverse events (AEs) were classified according to the Society of Interventional Radiology (SIR) and Clavien-Dindo (CD) classifications. Primary and secondary technical success of each procedure were recorded. RESULTS: Renal cell carcinoma (of any subtype) was found in 10 (71.5%) of the 14 masses that were biopsied. Tract cautery was used for transhepatic probes in 14 (63.6%) of 22 procedures. Three (13%) of 23 patients had postprocedural AEs. Two cases (8.6%) were hemorrhages related to transhepatic access (SIR moderate-2, CD 2; SIR severe-3, CD 1), and 1 case (4.4%) was related to bowel injury (SIR severe-3, CD 3a). There were no instances of pneumothorax. Tract cautery was used in the procedures that resulted in an AE. Primary technical success was achieved in 84.2% (16/19) of procedures, whereas secondary technical success was achieved in 2 additional patients. The secondary technical success rate was 94.7% (18/19). Four patients did not have imaging follow-up. CONCLUSIONS: The transhepatic approach to cryoablation of renal masses appears to have an acceptable safety profile and technical success rate. Larger studies, preferably comparative to nontranshepatic approach, are recommended.

Utility of the RENAL Nephrometry Scoring System in Predicting Adverse Events and Outcomes of Percutaneous Microwave Ablation of Renal Tumors.

PURPOSE: To assess the utility of the radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry scoring system at predicting adverse events and outcomes in percutaneous microwave ablation (MWA) of renal tumors. MATERIALS AND METHODS: A retrospective review of 116 patients who underwent MWA from 2004 to 2018 at 2 large university hospitals was conducted. Patient demographics and tumor characteristics were collected. The RENAL nephrometry scores were calculated, and procedure-related adverse events were stratified into minor and major (the Society of Interventional Radiology classification of class C or higher). Technical and oncologic outcomes were based on follow-up magnetic resonance imaging and computed tomography scans after ablation. RESULTS: The mean RENAL score was 6.6 (range, 4-11), and the mean tumor size was 24 mm. Follow-up ranged between 16 and 161 weeks (median, 50 weeks; mean, 65 weeks). Oncologic control was achieved in 96% (n = 111) of patients. The major and minor adverse event rates were 8.6% (n = 10) and 17% (n = 19), respectively. The mean RENAL score for patients with recurrent and/or residual tumor (8.2 ± 2.7) was higher than that for patients without disease recurrence (6.5 ± 3.5, P = .05). However, in a multivariate analysis, the RENAL score was not found to be an independent predictor of oncologic outcomes (odds ratio, 1.548; P = .092). CONCLUSIONS: The RENAL nephrometry score has minimal utility for predicting outcomes and adverse events in MWA of renal tumors. The inconsistent nature of RENAL nephrometry scoring in percutaneous ablation procedures underscores the need for an ablation-specific risk stratification system.

External Validation of the Percutaneous Renal Ablation Complexity Scoring System in Patients Undergoing Percutaneous Cryoablation or Microwave Ablation of Renal Tumors.

PURPOSE: To assess the ability of the Percutaneous Renal Ablation Complexity (P-RAC) scoring system to predict procedural complexity or adverse events (AEs) in adult patients undergoing percutaneous thermal ablation of renal tumors. MATERIALS AND METHODS: A retrospective review of 240 consecutive adult patients who underwent percutaneous thermal renal ablation from 2004 to 2018 was conducted. The P-RAC score was calculated for each renal tumor and procedural complexity recorded. A correlation coefficient was calculated for the P-RAC score and both the number of probes used and procedural duration. Receiver operating characteristic curves assessed the score's ability to predict the use of adjunctive techniques and/or major AEs, classified according to the Society of Interventional Radiology guidelines. RESULTS: For the entire cohort, there was a weak correlation between P-RAC scores and both the number of probes used (r = 0.31; P < .001) and procedural duration (r = 0.18; P = .03). When evaluating only patients treated with microwave ablation (MWA), no correlation between P-RAC scores and either the number of probes (P = .7) used or procedural duration (P = .4) was found. The area under the curve (AUC) for the P-RAC score to predict the use of adjunctive techniques was 0.55 and 0.53 for the entire cohort and MWA group, respectively. The AUC for the P-RAC score to predict major AEs was 0.70, 0.71, and 0.73 for the entire cohort, MWA group, and cryoablation group, respectively. CONCLUSIONS: The P-RAC scoring system is limited in its ability to predict percutaneous thermal renal tumor ablation procedural complexity, especially in patients treated with MWA. The scoring system may have a role in identifying patients at risk of major AEs.

Research Priorities in Percutaneous Image- and Endoscopy-Guided Interventions for Biliary and Gallbladder Diseases: Proceedings from the Society of Interventional Radiology Foundation Multidisciplinary Research Consensus Panel.

Recent technological advancements, including the introduction of disposable endoscopes, have enhanced the role of interventional radiology (IR) in the management of biliary and gallbladder diseases. There are unanswered questions in this growing field. The Society of Interventional Radiology Foundation convened a virtual research consensus panel consisting of a multidisciplinary group of experts to develop a prioritized research agenda regarding percutaneous image- and endoscopy-guided procedures for biliary and gallbladder diseases. The panelists discussed current data, opportunities for IR, and future efforts to maximize IR's ability and scope. A recurring theme throughout the discussions was to find ways to reduce the total duration of percutaneous drains and improve patients' quality of life. After the presentations and discussions, research priorities were ranked on the basis of their clinical relevance and impact. The research ideas ranked top 3 were as follows: (a) percutaneous multimodality management of benign anastomotic biliary strictures (laser vs endobiliary ablation vs cholangioplasty vs drain upsize protocol alone), (b) ablation of intraductal cholangiocarcinoma with and without stent placement, and (c) cholecystoscopy/choledochoscopy and lithotripsy in nonsurgical patients with calculous cholecystitis. Collaborative, retrospective, and prospective research studies are essential to answer these questions and improve the management protocols for patients with biliary and gallbladder diseases.

Role of Imaging in Renal Cell Carcinoma: A Multidisciplinary Perspective.

With the expansion in cross-sectional imaging over the past few decades, there has been an increase in the number of incidentally detected renal masses and an increase in the incidence of renal cell carcinomas (RCCs). The complete characterization of an indeterminate renal mass on CT or MR images is challenging, and the authors provide a critical review of the best imaging methods and essential, important, and optional reporting elements used to describe the indeterminate renal mass. While surgical staging remains the standard of care for RCC, the role of renal mass CT or MRI in staging RCC is reviewed, specifically with reference to areas that may be overlooked at imaging such as detection of invasion through the renal capsule or perirenal (Gerota) fascia. Treatment options for localized RCC are expanding, and a multidisciplinary group of experts presents an overview of the role of advanced medical imaging in surgery, percutaneous ablation, transarterial embolization, active surveillance, and stereotactic body radiation therapy. Finally, the arsenal of treatments for advanced renal cancer continues to grow to improve response to therapy while limiting treatment side effects. Imaging findings are important in deciding the best treatment options and to monitor response to therapy. However, evaluating response has increased in complexity. The unique imaging findings associated with antiangiogenic targeted therapy and immunotherapy are discussed. An invited commentary by Remer is available online. Online supplemental material is available for this article. ©RSNA, 2021.

Weight Loss after Left Gastric Artery Embolization: A Systematic Review and Meta-Analysis.

A systematic review of clinical trials investigating the safety and efficacy of left gastric artery (LGA) embolization as a bariatric procedure was performed. The Methodological Index for Nonrandomized Studies (MINORS) instrument was used for quality assessment. Patient characteristics, weight loss after embolization, and complications were reviewed. Meta-regression was performed to assess associations of age, sex, body mass index, and ghrelin and leptin levels with weight change after LGA embolization. The final meta-analysis included 6 nonrandomized prospective trials. Findings of 3 additional studies reporting weight changes after LGA embolization for control of gastrointestinal bleeding were also reviewed. Pooled analysis of 47 subjects with overweight/obesity showed mean ± SD weight loss after embolization of 8.1% ± 1.5% and 8.85 kg ± 1.24 kg (both P < .001) after a mean 12-month follow-up. Male sex (ß = 11.36 ± 5.79, P = .049) was associated with greater weight loss. Transient superficial mucosal ulcers were common after LGA embolization. One major adverse event comprising severe pancreatitis, splenic infarct, and gastric perforation was reported; treatment was supportive care. LGA embolization was associated with statistically significant weight loss and limited complications during short-term follow-up. Given that LGA embolization is an investigative method, it is important for researchers to follow standardized protocols and techniques to avoid complications.

Survival Outcomes of Very Small Drug-Eluting Beads Used in Chemoembolization of Unresectable Hepatocellular Carcinoma.

PURPOSE: To assess the safety and efficacy of transarterial chemoembolization using a 75-µm drug-eluting embolic (DEE) in patients with unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The medical records of 109 patients with a mean age of 64.1 years (range 85-49) treated for unresectable HCC between November 2013 and August 2016 with transarterial chemoembolization using a 75-µm DEE were retrospectively reviewed. Patients who had prior therapy for HCC were excluded. Child-Pugh A patients and Barcelona Clinic Liver Cancer stages A/B patients constituted 68.8% and 65.1% of the patients, respectively. The mean size of the index tumors was 5.8 cm (range 18.5-1.2) with 42 (39%) patients with central tumors around the porta-hepatis region. Portal vein invasion was seen in 10 (9.2%) patients. Tumor response was categorized according to the modified Response Evaluation Criteria in Solid Tumors 1.1, and the toxicity profile was assessed using Common Terminology Criteria for Adverse Events, version 4.03. RESULTS: At 1-month follow-up, complete response, objective response, and disease control was seen in 23%, 66%, and 90%, respectively. The median progression-free survival was 11.2 months. The median overall survival was 25.1 months (33.4 months for Child-Pugh A and 28.2 months for Barcelona Clinic Liver Cancer stages A/B), and transplant-free survival was 21.3 months. The 6-, 12-, and 24-month survivals were 91.7%, 75.5%, and 50.5%, respectively. Grade 3 toxicity was seen in 1.8% of the patients; no grade 4 or 5 toxicity was reported. CONCLUSIONS: Transarterial chemoembolization using 75-µm DEE is safe and efficacious in the treatment of HCC.

Psoas Muscle Density in Combination with Model for End-Stage Liver Disease Score Can Improve Survival Predictability in Transjugular Intrahepatic Portosystemic Shunts.

PURPOSE: To examine the role of psoas muscle density (PD) measurement before transjugular intrahepatic portosystemic shunt (TIPS) creation in predicting survival when combined with Model for End-stage Liver Disease (MELD) score. MATERIALS AND METHODS: The medical records of 241 patients with cirrhosis who underwent TIPS creation between June 2005 and June 2015 were retrospectively reviewed. The patients were divided into 2 groups: those with variceal bleeding (VB; n = 113) and those with volume overload (VO; n = 128). The study included 149 men (62%), and mean patient age was 56 years ± 9.6 (range 24-83). Mean MELD score before TIPS creation was 11.8 ± 5.7. A threshold sensitivity of pre-TIPS PD for the assessment of mortality was calculated and then correlated with survival after TIPS creation. Receiver operating characteristic curves comparing 12-month mortality were used to assess the improvement in survival predictability after TIPS creation when the PD threshold was combined with MELD score vs MELD score alone. RESULTS: Mean post-TIPS follow-up was 29.9 month ± 34.1 (range 1-3700 days). There was no significant difference in 3- or 12-month mortality rates between the VB and VO groups (32.7% vs 25.8% [P = .23] and 46% vs 46.1% [P = .99], respectively). The MELD score threshold for prediction of survival was 15 (P < .0001). There was no difference in the mean PD between VB and VO groups (34.2 HU ± 8.8 and 33.1 HU ± 10.3, respectively; P = .359). The increase in MELD score after TIPS creation was significant in both groups (VB, P = .0013; VO, P < .0001). The threshold of pre-TIPS PD for discrimination of survival was 29.4 HU (P < .0001), and PD measurements greater than this threshold were associated with a lower risk of mortality (hazard ratio, 0.27; 95% confidence interval, 0.13-0.57; P = .0006). Compared with the use of MELD score alone, the addition of PD measurement significantly increased the area under the curve from 0.61 to 0.68 (P = .0006). CONCLUSIONS: Measurement of PD improved overall survival predictability in patients with cirrhosis undergoing TIPS creation when used in conjunction with MELD score. The best survival outcome was observed in patients with MELD score < 15 in combination with PD > 29.4 HU.

Infection of Small-Bore Tunneled Central Venous Catheters.

OBJECTIVE. The purpose of this study is to evaluate the association of common clinical variables with small-bore tunneled central venous catheter (CVC) infection. MATERIALS AND METHODS. Retrospective data were collected from all small-bore (6-French) tunneled CVCs placed by the interventional radiology service between 2012 and 2015. Only patients who had a documented reason for tunneled CVC removal were included in the analysis to capture all events. Transfemoral, transhepatic, and translumbar placements were excluded to reduce cohort heterogeneity. Multiple clinical variables were collected from a review of the medical record. The t test and Fisher exact test were used for two-group comparisons for continuous variables and categoric variables, respectively. Logistic regression analyses were further used to identify variables that were associated with catheter infection. RESULTS. One hundred eighty-two patients (105 women [57.7%] and 77 men [42.3%]) with a mean (± SD) age of 49.7 ± 16 years were included. Thirty-two catheters (17.6%) were removed because of infection. Noninfected lines were removed at a mean of 39 (SD, 57.3) days, whereas infected lines were removed at a mean of 95.9 (SD, 113.4) days after placement (p < 0.001). There was a statistically significant difference in the number of tunneled CVCs removed for infection when the indication for tunneled CVC placement was the administration of IV antibiotics (p = 0.04). By multivariate analysis, only time to removal (p = 0.002; odds ratio, 0.992; 95% CI, 0.986-0.998) and a history of tunneled CVC (p = 0.01; odds ratio, 0.306; 95% CI, 0.121-0.772) were associated with catheter removal for infection. CONCLUSION. Time to catheter removal and history of tunneled CVC were associated with an increased risk of tunneled CVC removal because of infection.

Bowel Penetration by Inferior Vena Cava Filters: Feasibility and Safety of Percutaneous Retrieval.

OBJECTIVE. The purpose of this study was to evaluate the safety and technical feasibility of inferior vena cava filter (IVCF) removal when filter elements penetrate adjacent bowel. MATERIALS AND METHODS. A multicenter retrospective review of IVCF retrievals between 2008 and 2018 was performed. Adult patients with either CT or endoscopic evidence of filter elements penetrating bowel before retrieval were included. Technical success of IVCF retrieval was recorded. Patient records were assessed for immediate, 30-day, and 90-day complications after retrieval. RESULTS. Thirty-nine consecutive adult patients (11 men and 28 women; mean age, 51.2 years; age range, 18-81 years) qualified for inclusion. Filter dwell time was a median of 148 days (range, 32-5395 days). No IVCFs were known to have migrated or caused iliocaval thrombosis. Five IVCFs (12.8%) had more than 15° tilt relative to the inferior vena cava (IVC) before retrieval. Three IVCFs (7.7%) had fractured elements identified at the time of retrieval. Mean international normalized ratio (INR) was 1.24 ± 0.53 (SD), and mean platelet count was 262 ± 139 × 103/µL. Ten patients (25.6%) were on antibiotics at the time of retrieval. All 39 IVCFs were successfully retrieved (technical success = 100%). Two patients experienced minor complications in the immediate postprocedural period, which resulted in a minor complication rate of 5.1%. There were no complications (major or minor) identified in any patient at 30 or 90 days after retrieval. The overall major complication rate was 0%. CONCLUSION. Endovascular retrieval of IVCFs with CT evidence of filter elements that have penetrated adjacent bowel is both safe and technically feasible.

Interpretive Differences Between Patients and Radiologists Regarding the Diagnostic Confidence Associated With Commonly Used Phrases in the Radiology Report.

OBJECTIVE: Despite patients' increasing interest in reading their own imaging results, little is known about how patients interpret the reporting terminology of radiologists. The purpose of this study was to survey patients and radiologists to improve understanding of how each group views commonly used phrases within the radiology report. SUBJECTS AND METHODS: Patients and radiologists were asked to assign a numerical likelihood of the presence of metastatic disease based on their understanding of radiology report phrasing. Commonly used qualifying phrases, such as "likely represents," "concerning for," and "cannot exclude" were evaluated to compare differences in interpretation between patients and radiologists. Potential responses for statistical likelihoods included 0-25%, 26-50%, 51-75%, 76-99%, and 100%. RESULTS: There was a significant difference between the two groups with respect to assigned statistical likelihoods for most phrases. Patients identified the phrase "probably meta-static disease" as conferring the highest likelihood of true malignancy, even though radiologists rated this phrase as conferring the sixth highest likelihood (p = 0.002). Radiologists consistently identified the phrase "diagnostic for metastatic disease" as conveying the highest likelihood of metastatic disease, whereas patients ranked this phrase as having the third highest numerical likelihood (p < 0.001). The phrase "cannot exclude cancer" was assigned the lowest numerical likelihood by both groups. CONCLUSION: Patients and radiologists have differing perceptions of the specific semantic meaning of the language in radiology reports. A variable interpretation of the radiologist's diagnostic confidence may lead to confusion and dissatisfaction with the report. Radiologists should consider that patients read their reports and should endeavor to use strategies to convey imaging results clearly and effectively.

Radiology Reporting: Current Practices and an Introduction to Patient-Centered Opportunities for Improvement.

OBJECTIVE: As health care evolves, the radiology report must also change to satisfy referring physician and patient expectations. Knowledge of the issues and controversies regarding a patient-centered approach to reporting practices is important. This article will aid the radiologist in this endeavor by summarizing key facets of radiology reporting, including current reporting standards and emerging patient-centered concepts in report language, formatting, and delivery. CONCLUSION: Future efforts to improve radiology reporting practices need to account for the needs of an increasingly heterogeneous audience that includes patients. Radiologists must exploit information technologies to craft and deliver meaningful patient-centered reports. A modern radiology report will be a powerful, flexible document that strengthens the connection between the radiologist and the patient.

Role of Angio-Embolization for Renal Cell Carcinoma.

PURPOSE OF REVIEW: To provide the technical aspects of, clinical indications for, status of the current literature on, and emerging concepts in trans-arterial embolization (TAE) for renal cell carcinoma. RECENT FINDINGS: TAE has been evaluated in several retrospective series as a neoadjuvant therapy prior to surgical resection of RCC to reduce tumor vascularity and minimize intra-operative blood loss. TAE has also been examined retrospectively as a neoadjuvant therapy prior to the percutaneous ablation of RCC to reduce blood loss and procedural complications. TAE can potentially palliate symptoms of RCC such as pain and hematuria. Trans-arterial chemoembolization and trans-arterial radioembolization are emerging concepts for RCC. Although there have been no prospective, randomized trials demonstrating improved clinical or oncologic outcomes from TAE for patients with RCC, several retrospective studies have shown encouraging results.

JOURNAL CLUB: Structured Feedback From Patients on Actual Radiology Reports: A Novel Approach to Improve Reporting Practices.

OBJECTIVE: Patient perceptions of radiology reports are largely unknown. The objective of the present study is to describe our experience receiving structured feedback from patients on actual radiology reports as a means of improving reporting practices. MATERIALS AND METHODS: Eight reports (two for radiographs, two for ultrasound images, two for CT scans, and two for MR images) were randomly selected from our system for review. For each report, patients were asked to rate their level of comprehension, identify any problems in the report, and, in the free-text portion of the feedback form, indicate any questions about the report that they may have. Potentially confounding factors were also examined. RESULTS: A total of 104 patients (46 men and 58 women) participated in the study (for a total of 832 evaluations). The median score for report comprehension was 2.5 (on a scale of 1-5), with the most common problems affecting comprehension identified as "unclear or technical language" (mentioned in 59.6% of evaluations) and the report being "too long" (mentioned in 10.2% of evaluations). A request for an explanation of the report in lay terms (noted in 20.1% of evaluations) was the most common request mentioned in the free-text portion of the feedback form. An inverse relationship existed between report length and patient comprehension (p < 0.001). Patients who had prior experience with their own radiology reports indicated having greater comprehension than did patients with no prior experience (p = 0.003). No correlation between the educational status and report comprehension of the patients was identified (p = 0.488). CONCLUSION: Radiology reports are not well understood by patients, who identify technical language and the long length of reports as the most common problems affecting their comprehension. Longer reports tend to be less well understood.

Bariatric embolization of the gastric arteries for the treatment of obesity.

Obesity is a public health epidemic in the United States that results in significant morbidity, mortality, and cost to the health care system. Despite advancements in therapeutic options for patients receiving bariatric procedures, the number of overweight and obese individuals continues to increase. Therefore, complementary or alternative treatments to lifestyle changes and surgery are urgently needed. Embolization of the left gastric artery, or bariatric arterial embolization (BAE), has been shown to modulate body weight in animal models and early clinical studies. If successful, BAE represents a potential minimally invasive approach offered by interventional radiologists to treat obesity. The purpose of the present review is to introduce the interventional radiologist to BAE by presenting its physiologic and anatomic bases, reviewing the preclinical and clinical data, and discussing current and future investigations.