Venous Thrombosis Assay in a Mouse Model of Cancer.

This methodology paper highlights the surgical nuances of a rodent model of venous thrombosis, specifically in the context of cancer-associated thrombosis (CAT). Deep venous thrombosis is a common complication in cancer survivors and can be potentially fatal. The current murine venous thrombosis models typically involve a complete or partial mechanical occlusion of the inferior vena cava (IVC) using a suture. This procedure induces a total or partial stasis of blood and endothelial damage, triggering thrombogenesis. The current models have limitations such as higher variability in clot weights, significant mortality rate, and prolonged learning curve. This report introduces surgical refinements using vascular clips to address some of these limitations. Using a syngeneic colon cancer xenograft mouse model, we employed customized vascular clips to ligate the infrarenal vena cava. These clips allow residual lip space similar to a 5-0 polypropylene suture after IVC ligations. Mice with the suture method served as controls. The vascular clip method resulted in a consistent reproducible partial vascular occlusion and greater clot weights with less variability than the suture method. The larger clot weights, greater clot mass, and clot to the IVC luminal surface area were expected due to the higher pressure profile of the vascular clips compared to a 6-0 polypropylene suture. The approach was validated by gray scale ultrasonography, which revealed consistently greater clot mass in the infrarenal vena cava with vascular clips compared to the suture method. These observations were further substantiated with the immunofluorescence staining. This study offers an improved method to generate a venous thrombosis model in mice, which can be employed to deepen the mechanistic understanding of CAT and in translational research such as drug discovery.

ACR Appropriateness Criteria® Pulsatile Abdominal Mass, Suspected Abdominal Aortic Aneurysm: 2023 Update.

Abdominal aortic aneurysm (AAA) is defined as abnormal dilation of the infrarenal abdominal aortic diameter to 3.0 cm or greater. The natural history of AAA consists of progressive expansion and potential rupture. Although most AAAs are clinically silent, a pulsatile abdominal mass identified on physical examination may indicate the presence of an AAA. When an AAA is suspected, an imaging study is essential to confirm the diagnosis. This document reviews the relative appropriateness of various imaging procedures for the initial evaluation of suspected AAA. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

ACR Appropriateness Criteria® Nontraumatic Aortic Disease.

Nontraumatic aortic disease can be caused by a wide variety of disorders including congenital, inflammatory, infectious, metabolic, neoplastic, and degenerative processes. Imaging examinations such as radiography, ultrasound, echocardiography, catheter-based angiography, CT, MRI, and nuclear medicine examinations are essential for diagnosis, treatment planning, and assessment of therapeutic response. Depending upon the clinical scenario, each of these modalities has strengths and weaknesses. Whenever possible, the selection of a diagnostic imaging examination should be based upon the best available evidence. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment. The purpose of this document is to assist physicians select the most appropriate diagnostic imaging examination for nontraumatic aortic diseases.

ACR-ABS-ACNM-ASTRO-SIR-SNMMI practice parameter for selective internal radiation therapy or radioembolization for treatment of liver malignancies.

PURPOSE: The American College of Radiology (ACR), American Brachytherapy Society (ABS), American College of Nuclear Medicine (ACNM), American Society for Radiation Oncology (ASTRO), Society of Interventional Radiology (SIR), and Society of Nuclear Medicine and Molecular Imaging (SNMMI) have jointly developed a practice parameter on selective internal radiation therapy (SIRT) or radioembolization for treatment of liver malignancies. Radioembolization is the embolization of the hepatic arterial supply of hepatic primary tumors or metastases with a microsphere yttrium-90 brachytherapy device. MATERIALS AND METHODS: The ACR -ABS -ACNM -ASTRO -SIR -SNMMI practice parameter for SIRT or radioembolization for treatment of liver malignancies was revised in accordance with the process described on the ACR website (https://www.acr.org/ClinicalResources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters-Interventional and Cardiovascular Radiology of the ACR Commission on Interventional and Cardiovascular, Committee on Practice Parameters and Technical Standards-Nuclear Medicine and Molecular Imaging of the ACR Commission on Nuclear Medicine and Molecular Imaging and the Committee on Practice Parameters-Radiation Oncology of the ACR Commission on Radiation Oncology in collaboration with ABS, ACNM, ASTRO, SIR, and SNMMI. RESULTS: This practice parameter is developed to serve as a tool in the appropriate application of radioembolization in the care of patients with conditions where indicated. It addresses clinical implementation of radioembolization including personnel qualifications, quality assurance standards, indications, and suggested documentation. CONCLUSIONS: This practice parameter is a tool to guide clinical use of radioembolization. It focuses on the best practices and principles to consider when using radioemboliozation effectively. The clinical benefit and medical necessity of the treatment should be tailored to each individual patient.

A Water-Based Liquid Embolic: Evaluation of its Safety and Efficacy in a Rabbit Kidney Model.

PURPOSE: To evaluate a novel aqueous-based liquid embolic (Embrace Hydrogel Embolic System, [HES]) that has been developed to embolize hypervascular tumors by filling the tumor vascular bed and solidifying into a hydrogel. HES was evaluated for embolization safety and efficacy relative to microspheres in a preclinical rabbit kidney model. MATERIALS AND METHODS: A renal embolization model in New Zealand white rabbits was utilized. Twenty-four rabbits underwent unilateral kidney embolization via the main renal artery with either HES or 40-µm microspheres. Twenty-two rabbits survived the procedure and were monitored for 2, 12, 17.5, or 26 weeks before sacrifice. All rabbits underwent a repeat renal angiogram before necropsy. HES was evaluated for nontarget embolization, safety, and embolization effectiveness as measured by recanalization and viability of embolized tissue. RESULTS: Both embolization materials were found to be safe, with targeted tissue necrosis and absence of nontarget embolization. Prenecropsy angiograms found vascular recanalization in 0/14 (0%) HES-embolized kidneys and in 3/8 (38%) microsphere-embolized kidneys (P = .036). Viable kidney tissue was observed in 2/14 (14%) kidneys embolized with HES and 5/8 (63%) kidneys embolized with microspheres (P = .052). All kidneys embolized with microspheres that showed vascular recanalization had viable tissue on histological sections. HES was observed in vessels as small as 10 µm in diameter in histological analysis. CONCLUSIONS: HES provided deep, durable vascular bed embolization that resulted in less recanalization and, on an average, less viable target tissue compared with 40-µm microspheres. No systemic effects or nontarget tissue embolization was identified.

Efficacy of TIPS Reduction for Refractory Hepatic Encephalopathy, Right Heart Failure, and Liver Dysfunction.

OBJECTIVE. The purpose of this study was to determine clinical outcomes of patients undergoing TIPS reduction. MATERIALS AND METHODS. In this institutional review board-approved, HIPAA-compliant study, all TIPS reductions performed at two institutions from January 1, 2008 to January 31, 2016, were retrospectively identified. Patients were divided into two groups according to pre-TIPS symptoms: volume overload due to ascites or hydrothorax (VO; n = 14) or variceal bleeding (VB; n = 12). Patient demographics, pre-TIPS model for end-stage liver disease score, pre- and post-TIPS portosystemic gradients, and clinical parameters were recorded. The primary endpoint was change in symptoms of hepatic encephalopathy (HE; West Haven criteria), right heart failure, or liver dysfunction. Secondary endpoints included paracentesis rate for the VO group and rebleeding for the VB group. RESULTS. The degree of HE increased in 24 of 26 patients (92%) after TIPS placement and decreased in 24 of 26 patients (92%) after TIPS reduction. Mean West Haven scores for the VO group decreased after TIPS reduction (from 2.57 ± 0.97 [SD] to 1.07 ± 0.70; p < .001). Mean West Haven scores for the VB group also decreased after TIPS reduction (from 2.45 ± 0.89 to 1.27 ± 0.86; p = .007). Right heart failure improved in two of three patients (67%), and total bilirubin improved in one of three patients (33%). Follow-up data were available up to median of 134 days (interquartile range, 44-286). TIPS reduction led to an increased paracentesis rate compared with before TIPS placement in four of 14 patients with VO (29%). One patient had a stable paracentesis rate after TIPS reduction compared with before TIPS placement. Variceal rebleeding did not occur in any patients with VB after TIPS reduction. At 54 days after TIPS reduction, one of the 12 patients with VB (9%) experienced hematemesis due to an endoscopically proven band-related ulcer. CONCLUSION. TIPS reduction successfully resolved HE and refractory right heart failure in most patients. In patients with VB, TIPS reduction with variceal embolization results in a low risk of short-term recurrent VB. However, in patients with VO, ascites may return or worsen after TIPS reduction despite improvement in HE.

Yttrium-90 Hepatic Radioembolization for Advanced Chemorefractory Metastatic Colorectal Cancer: Survival Outcomes Based on Right- Versus Left-Sided Primary Tumor Location.

BACKGROUND. Primary colon cancer location affects survival of patients with metastatic colorectal cancer (mCRC). Outcomes based on primary tumor location after salvage hepatic radioembolization with 90Y resin microspheres are not well studied. OBJECTIVE. The objectives of this study are to assess the survival outcomes of patients with advanced chemorefractory mCRC treated with 90Y radioembolization, as stratified by primary tumor location, and to explore potential factors that are predictive of survival. METHODS. A total of 99 patients who had progressive mCRC liver metastases while receiving systemic therapy and who were treated with 90Y radioembolization at a single center were retrospectively analyzed. For 89 patients, tumor response on the first imaging follow-up examination (CT or MRI performed at a mean [± SD] of 1.9 ± 0.9 months after 90Y radioembolization) was evaluated using RECIST. Overall survival (OS), OS after 90Y radioembolization, and hepatic progression-free survival (PFS) were calculated using the Kaplan-Meier method. Outcomes and associations of outcomes with tumor response were compared between patients with left- and right-sided tumors. RESULTS. A total of 74 patients had left-sided colon cancer, and 25 patients had right-sided colon cancer. Median OS from the time of mCRC diagnosis was 37.2 months, median OS after 90Y radioembolization was 5.8 months, and median hepatic PFS was 3.3 months. Based on RECIST, progressive disease on first imaging follow-up was observed in 38 patients (43%) after 90Y radioembolization and was associated with shorter OS after 90Y radioembolization compared with observation of disease control on first imaging follow-up (4.0 vs 10.5 months; p < .001). Patients with right-sided primary tumors showed decreased median OS after 90Y radioembolization compared with patients with left-sided primary tumors (5.4 vs 6.2 months; p = .03). Right- and left-sided primary tumors showed no significant difference in RECIST tumor response, hepatic PFS, or extrahepatic disease progression (p > .05). Median survival after 90Y radioembolization was significantly lower among patients with progressive disease than among those with disease control in the group with left-sided primary tumors (4.2 vs 13.9 months; p < .001); however, this finding was not observed in the group with right-sided primary tumors (3.3 vs 7.2 months; p = .05). CONCLUSION. Right-sided primary tumors were independently associated with decreased survival among patients with chemorefractory mCRC after 90Y radioembolization, despite these patients having a similar RECIST tumor response, hepatic PFS, and extrahepatic disease progression compared with patients with left-sided primary tumors. CLINICAL IMPACT. Primary colon cancer location impacts outcomes after salvage 90Y radioembolization and may help guide patient selection.

Small-diameter TIPS combined with splenic artery embolization in the management of refractory ascites in cirrhotic patients.

PURPOSE: Maximally decreasing portal pressures with transjugular intrahepatic portosystemic shunt (TIPS) is associated with improved ascites control but also increased encephalopathy incidence. Since splenic venous flow contributes to portal hypertension, we assessed if combining small-diameter TIPS with splenic artery embolization could improve ascites while minimizing encephalopathy. METHODS: Fifty-five patients underwent TIPS creation for refractory ascites. Subjects underwent creation of 8 mm TIPS followed by proximal splenic artery embolization (group A, n=8), or of 8 mm (group B, n=6) or 10 mm TIPS (group C, n=41) without splenic embolization. Data were retrospectively reviewed. RESULTS: In group A, median portosystemic gradient decreased from 19 mmHg to 9 mmHg after TIPS, and 8 mmHg after subsequent splenic artery embolization. In groups B and C, gradient decreased from 15 mmHg to 8 mmHg and 16 mmHg to 6 mmHg. All patients except for one in group A and two in C had greater than 50% reduction in the number of paracenteses in 3 months. Any postprocedural encephalopathy incidence was 62%, 50%, 83% in groups A, B, and C, respectively. Overall, 20% of subjects with 10 mm TIPS required TIPS reduction/closure compared to 7% of subjects with 8 mm TIPS. CONCLUSION: We found that 8 mm diameter TIPS provided similar ascites control compared to 10 mm TIPS regardless of splenic embolization. While more patients with 10 mm TIPS required reduction/closure for severe encephalopathy, the study was underpowered for definitive assessment. Splenic embolization might have the potential to further decrease portosystemic gradient and ascites as an alternative to dilation of TIPS to 10 mm minimizing the risk of encephalopathy, but larger studies are warranted.

Repeat Evaluation of Lung Shunt Fraction is Unnecessary: A Retrospective Observational Study of Successive Lung Shunt Fractions from Variable Arterial Distributions in Patients Undergoing Radioembolization of Primary and Secondary Liver Tumors.

PURPOSE: To evaluate whether the recalculation of lung shunt fraction (LSF) is necessary prior to next-stage or same lobe repeat radioembolization. MATERIALS AND METHODS: Retrospective chart review was performed for patients who underwent radioembolization between February 2008 and December 2018. Eighty of 312 patients had repeat mapping angiograms and LSF calculations. A total of 160 LSF calculations were made using planar imaging (155, [97%]) and single-photon emission computed tomography (5 [3%]) technetium-99m macroaggregated albumin hepatic arterial injection imaging. The mean patient age was 61.8 years ± 12.7; 69 (86%) patients had metastatic disease and 11 (14%) had hepatocellular carcinoma. RESULTS: Patients had a median LSF of 5% (interquartile range [IQR] 3%-9%) with a median absolute difference of 1.25 (IQR 0.65-3.4) and a median of 76 days (IQR 42.5-120 days) between repeat LSF calculations. There was a median change in LSF of 0.2% between mapping studies (P = .11). There was no statistical significance between the repeat LSFs regardless of the arterial distribution (P = .79) or between tumor types (P = .75). No patients exceeded lung dose limits using actual or predicted prescribed dose amounts. The actual median lung dose was 2.6 Gy (IQR 1.8-4.4 Gy, maximum = 20.5) for the first radioembolization and 2.0 Gy (IQR 1.3-3.7 Gy, maximum = 10.1) for the second radioembolization. CONCLUSIONS: No significant difference in LSF was identified between different time points and arterial distributions within the same patient undergoing repeat radioembolization. In patients who receive well under 30-Gy lung dose for the initial treatment and a 50-Gy cumulative lung dose, repeat radioembolization treatments in the same patient may not require a repeat LSF calculation.

Thermal Ablation, Embolization, and Selective Internal Radiation Therapy Combined with Checkpoint Inhibitor Cancer Immunotherapy: Safety Analysis.

PURPOSE: To describe interventional oncology therapies combined with immune checkpoint inhibitor (ICI) therapy targeting the programmed death 1 pathway in patients with different neoplasms. MATERIALS AND METHODS: This was a retrospective cohort study of patients who underwent tumor-directed thermal ablation, embolization, or selective internal radiation therapy (SIRT) between January 1, 2011, and May 1, 2019, and received anti-programmed death 1/PD-L1 agents ≤ 90 days before or ≤ 30 days after the interventional procedure. Immune-related adverse events (irAEs) and procedural complications ≤ 90 days after the procedure were graded according to the Common Terminology Criteria for Adverse Events version 5.0. The study included 65 eligible patients (49% female; age 63 years ± 11.1). The most common tumors were metastatic melanoma (n = 28) and non-small cell lung cancer (NSCLC) (n = 12). Patients underwent 78 procedures (12 patients underwent > 1 procedure), most frequently SIRT (35.9%) and cryoablation (28.2%). The most common target organs were liver (46.2%), bone (24.4%), and lung (9.0%). Most patients received ICI monotherapy with pembrolizumab (n = 30), nivolumab (n = 22), and atezolizumab (n = 6); 7 patients received ipilimumab and nivolumab. RESULTS: Seven (10.8%) patients experienced an irAE (71.4% grade 1-2), mostly affecting the skin. Median time to irAE was 33 days (interquartile range, 19-38 days). Five irAEs occurred in patients with melanoma, and no irAEs occurred in patients with NSCLC. Management required corticosteroids (n = 3) and immunotherapy discontinuation (n = 1); all irAEs resolved to grade ≤ 1. There were 4 intraprocedural and 32 postprocedural complications (77.8% grade < 3). No grade 5 irAEs and/or procedural complications occurred. CONCLUSIONS: No unmanageable or unanticipated toxicities occurred within 90 days after interventional oncology therapies combined with ICIs.

Interventional Treatment of Hepatic Metastases from Colorectal Cancer.

Modern systemic therapies provide a significant survival benefit in metastatic colorectal cancer. Despite these advances, the durability of response remains limited and nearly all patients progress on systemic treatment. Colorectal liver metastases (CLM) develop in approximately half of patients with metastatic disease and contribute to mortality in most patients. In selected patients, surgical resection of hepatic metastases prolongs survival, indicating the benefits of the targeted treatment of CLM through alternate means. Minimally invasive interventional treatments offer the promise of treating CLM in a wider range of patients than those eligible for surgical resection. Thermal ablation and intra-arterial therapies, including chemoembolization and radioembolization, are commonly used in the treatment of CLM. Each of these treatment modalities will be discussed in detail with an emphasis on the available clinical data for each interventional treatment for CLM.

Transjugular Intrahepatic Portosystemic Shunt Placement for Portal Hypertension: Meta-Analysis of Safety and Efficacy of 8 mm vs. 10 mm Stents.

INTRODUCTION: Hepatic encephalopathy (HE) following transjugular intrahepatic portosystemic shunt (TIPS) placement remains a leading adverse event. Controversy remains regarding the optimal stent diameter given that smaller stents may decrease the amount of shunted blood and decrease the risk of HE, but stent patency and/or clinical adequacy of portal decompression may also be affected. We aim to provide meta-analysis-based evidence regarding the safety and efficacy of 8 mm vs. 10 mm stents during TIPS placement. METHODS: PubMed, Embase, Cochrane Library, and Web of Science were searched for studies comparing 8 mm and 10 mm stents during TIPS placement for portal hypertension decompression in cirrhotic patients. Randomized controlled trials and cohort studies were prioritized for inclusion. Overall evaluation of quality and bias for each study was performed. The outcomes assessed were the prevalence of HE, rebleeding or failure to control refractory ascites, and overall survival. Subgroup analysis based on TIPS indication was conducted. RESULTS: Five studies with a total number of 489 cirrhotic patients were identified. The pooled hazard ratio (HR) of post-TIPS HE was significantly lower in patients in the 8 mm stent group than in the 10 mm stent group (HR: 0.68, 95% CI: 0.51~0.92, p value < 0.0001). The combined HR of post-TIPS rebleeding/the need for paracentesis was significantly higher in patients in the 8 mm stent group than in the 10 mm stent group (HR: 1.76, 95% CI: 1.22~2.55, p value < 0.0001). There was no statistically significant difference in the overall survival between the 8 mm and 10 mm stent groups. The combined risk of HE in the variceal bleeding subgroup was statistically lower (HR: 0.52, CI: 0.34-0.80) with an 8 mm stent compared with a 10 mm stent. The combined risk of both rebleeding/paracentesis and survival was not statistically significant between 8 mm and 10 mm stent use in subgroup analysis. CONCLUSION: 8 mm stents during TIPS placement are associated with a significant lower risk of HE compared to 10 mm stents (32% decreased risk), as well as a 76% increased risk of rebleeding/paracentesis. Meta-analysis results suggest that there is not one superior stent choice for all clinical scenarios and that the TIPS indication of variceal bleeding or refractory ascites might have different appropriate selection of the shunt diameter.

Partial splenic embolization is superior to intravenous somatostatin for decreasing portal pressure in cirrhotic patients: a dynamic self-controlled cohort study.

AIMS: The efficacy of somatostatin in altering splanchnic hemodynamics in cirrhotic portal hypertension is still controversial. We aimed to establish the dynamic effect of somatostatin on portal pressure in cirrhotic patients and compared its effect with Partial Splenic Embolization (PSE). METHODS: Eighteen patients with cirrhotic portal hypertension were prospectively recruited. The wedged hepatic venous pressure (WHVP) and free hepatic venous pressure (FHVP) were repeatedly measured at baseline, 1-, 5-, 10- and 20-min after initiating somatostatin infusion. After somatostatin infusion cessation and washout, WHVP and FHVP were measured before and after PSE. The change in all the variables between time points was analyzed. RESULTS: Decreased hepatic venous pressure gradient (HVPG) 5-min after initiation of infusion was identified compared with baseline level (19.6%; p-value: .042), which was achieved through elevated FHVP (37.5%; p-value: 9.26e - 04). There was no significant decrease in WHVP at any time point during somatostatin infusion. The HVPG (17.4%; p-value: 1.27e - 04) and WHVP (10.4%; p-value: 3.00e - 03) post-PSE significantly decreased compared to the washout level. No significant distribution differences in the number of patients with HVPG decrease by a percentage relative to the baseline level were identified between the 5-min time point and post-PSE. CONCLUSION: Our study indicates that somatostatin administration does not decrease WHVP within 20 min at clinically recommended doses. While somatostatin did decrease HVPG, this effect was achieved through increased FHVP, providing a possible explanation for its unclear efficacy. In contrast, PSE decreases both the WHVP and the HVPG.

Radiation Effective Dose Above 100 mSv From Fluoroscopically Guided Intervention: Frequency and Patient Medical Condition.

OBJECTIVE. The purpose of this article was to investigate the medical condition of patients who received substantial cumulative effective dose (CED) in fluoroscopically guided interventional (FGI) procedures. MATERIALS AND METHODS. We examined 25,253 patients (mean age, 58.2 years; 50.6% male) who underwent 46,491 FGI procedures at a tertiary care center in the United States from January 2010 to January 2019. Radiation dosage data were retrieved from an in-house semiautomated dose-tracking system. A cohort was identified as those who received a CED of 100 mSv or greater and was categorized by medical disorder from longitudinal medical records. Statistical software was used to determine mean value, five percentiles (10th, 25th, 50th, 75th, 95th), and interquartile range for age and dose. RESULTS. Among 1011 (4.0%) patients (30.4% female) with a CED of 100 mSv or more, the median number of procedures was 2.0, the median age at first procedure was 60.0 years old, and the median value of CED was 177.2 mSv. The patients' medical disorders included cancer (36.7%), chronic disease of the torso (30.0%), internal bleeding (24.8%), trauma (4.6%), organ transplant (3.2%) and cerebrovascular disease (0.7%). Eight-hundred (79.1%) patients underwent all of their procedures within 365 days. CONCLUSION. This is the first cohort study of the medical condition of patients receiving substantial cumulative doses from FGI procedures over a long period. In the critical care of patients with serious medical disorders, 4.0% of patients may be exposed to substantial radiation dose (CED ≥ 100 mSv). The risks associated with such a high level of radiation warrant continued attention.

ACR Appropriateness Criteria® Thoracic Outlet Syndrome.

Thoracic outlet syndrome (TOS) is the clinical entity that occurs with compression of the brachial plexus, subclavian artery, and/or subclavian vein at the superior thoracic outlet. Compression of each of these structures results in characteristic symptoms divided into three variants: neurogenic TOS, venous TOS, and arterial TOS, each arising from the specific structure that is compressed. The constellation of symptoms in each patient may vary, and patients may have more than one symptom simultaneously. Understanding the various anatomic spaces, causes of narrowing, and resulting neurovascular changes is important in choosing and interpreting radiological imaging performed to help diagnose TOS and plan for intervention. This publication has separated imaging appropriateness based on neurogenic, venous, or arterial symptoms, acknowledging that some patients may present with combined symptoms that may require more than one study to fully resolve. Additionally, in the postoperative setting, new symptoms may arise altering the need for specific imaging as compared to preoperative evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Clinically Suspected Vascular Malformation of the Extremities.

Vascular malformations of the extremities represent a wide spectrum of lesions, broadly divided into high-flow and low-flow categories. High-flow lesions include arteriovenous malformations and arteriovenous fistulas, while the more common low-flow lesions consist of venous and lymphatic malformations. The clinical presentation of vascular malformations is variable and can include extremity pain, discoloration, focal mass, or diffuse extremity enlargement. A vascular murmur can also be present and is more typical of high-flow lesions. While vascular malformations can often be diagnosed or strongly suspected by clinical features alone, imaging is often used to confirm the diagnosis, determine lesion characteristics and extent, and/or plan for treatment. Among the imaging options available, those usually appropriate for initial imaging of suspected vascular malformation are MR angiography without and with intravenous contrast, MRI without and with intravenous contrast, CT angiography with intravenous contrast, or US duplex Doppler. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Patterns of Care and Outcomes of Definitive External Beam Radiotherapy and Radioembolization for Localized Hepatocellular Carcinoma: A Propensity Score-adjusted Analysis.

OBJECTIVES: Most localized hepatocellular carcinoma (HCC) patients are not surgically operable or transplantation candidates, increasing the role for nonsurgical therapies. Ablative external beam radiotherapy (XRT) and transarterial radioembolization (TARE) are emerging radiotherapeutic treatments for localized HCC. We sought to evaluate their utilization and efficacy in a large nationwide cohort. MATERIALS AND METHODS: We conducted an observational study of 2685 patients from the National Cancer Database (NCDB) diagnosed with American Joint Committee on Cancer 7th edition clinical stage I to III HCC between 2004 and 2015, treated with definitive-intent XRT delivered in 1 to 15 fractions or TARE. The association between treatment modality (XRT vs. TARE) and overall survival (OS) was defined using propensity score-weighted Kaplan-Meier estimators and propensity score-weighted multivariable Cox regressions. RESULTS: Among 2685 patients, 2007 (74.7%) received TARE and 678 (25.3%) received XRT, with increasing usage for both from 2004 to 2015 (Ptrend<0.001), but with overall greater uptake and absolute usage of TARE. Patients who received TARE were more likely to have elevated alpha fetoprotein and more advanced stage (P<0.05 for all). Median OS was 14.5 months for the entire cohort. XRT was associated with an OS advantage compared with TARE on propensity score-unadjusted analysis (adjusted hazard ratio [AHR], 0.89; 95% confidence interval, 0.79-1.00; P=0.049), but not on propensity score-adjusted analysis (AHR, 0.99; 95% confidence interval, 0.86-1.13; P=0.829). CONCLUSIONS: Our study demonstrates that while both XRT and TARE usage have increased with time, there was greater uptake and absolute use of TARE. We found no difference in survival between XRT and TARE after propensity score adjustment.

Evaluation of model performance to predict survival after transjugular intrahepatic portosystemic shunt placement.

BACKGROUND/AIMS: The MELD score was developed to predict survival after transjugular intrahepatic portosystemic shunt (TIPS) placement. Given changes in practice patterns and development of new prognostic tools in cirrhosis, we aimed to evaluate common models to predict mortality after TIPS placement. METHODS: Analysis of consecutive patients who underwent TIPS placement for ascites or bleeding. Performance to predict 90-day mortality was assessed by C statistic for six models (MELD, MELD-Na, CLIF-C ACLF, Child-Pugh, Platelet-Albumin-Bilirubin, and Emory score). Added predictive value to MELD score was assessed for univariate predictors of 90-day mortality. Stratified analysis by TIPS indication, emergent placement status, and TIPS stent type was performed. RESULTS: 413 patients were analyzed (248 with variceal bleeding, 165 with refractory ascites). 90-day mortality was 27% (113/413). Mean MELD score was 15 ± 7.9. MELD score best predicted mortality for all patients (c = 0.779), for variceal bleeding (c = 0.844), and for emergent TIPS (c = 0.817). CLIF-C ACLF score best predicted mortality for refractory ascites (c = 0.707). Addition of sodium to the MELD score did not improve predictive value across multiple strata. Addition of hemoglobin improved MELD score's predictive value in variceal bleeding. Addition of age improved MELD score's predictive value in refractory ascites. CONCLUSIONS: MELD score best predicted 90-day mortality. Addition of sodium to the MELD score did not improve its performance, though mortality prediction was improved using Age-MELD for ascites and Hemoglobin-MELD for bleeding. An individualized risk stratification approach may be best when considering candidates for TIPS placement.