Guy E. Johnson

Hepatocellular carcinoma remains a prominent cause of cancer-related mortality globally. Transarterial yttrium-90 radioembolization is a versatile therapy and plays an important role in the treatment of hepatocellular carcinoma. This review summarizes the establishment of radioembolization in the hepatocellular carcinoma treatment paradigm, treatment considerations across cancer stages, and recent advances in evidence.

Transarterial radioembolization using yttrium-90 (Y-90) microspheres is an important therapy in the management of unresectable primary liver tumors or hepatic metastases. While radioembolization is generally well-tolerated, it is not free from adverse events, and familiarity with the prevention and treatment of radioembolization-specific complications is an important component of patient care. This article aims to review radioembolization-specific toxicities stratified by hepatic, extrahepatic, and systemic effects, with a focus on preventing and mitigating radioembolization-induced morbidity.

Traumatic injury is the leading cause of death worldwide in younger patient populations and extremity trauma with associated vascular injury accounts for many trauma-related deaths. Iatrogenic injury is also a common cause of extremity vascular trauma and the incidence of iatrogenic injury will likely increase as endovascular techniques continue to become more ubiquitous. For many vascular injuries involving the extremities, surgical repair is viewed as the standard of care. Historically, endovascular techniques did not play a role in the treatment of these vascular injuries, rather they were utilized only as part of the diagnostic assessment; however, there is an increasing trend toward endovascular management of extremity vascular trauma. No validated, widely implemented algorithm to select patients for endovascular intervention exists. Transcatheter techniques, however, play an important role in the management of these patients. For arterial injuries, embolization can be used to rapidly achieve hemostasis if the vessel can be sacrificed. More advanced endovascular techniques such as stent-graft placement may be best employed in the context of isolated, proximal extremity injuries, although there is increasing literature supporting the use of advanced techniques for more distal arterial injuries. The management of peripheral venous trauma remains controversial; however, there is growing data describing successful endovascular management of some peripheral venous injuries. The purpose of this article is to review extremity vascular trauma, concepts of injury triage, endovascular techniques, and intraprocedural considerations.

Superselective transarterial radioembolization, or radiation segmentectomy, is a novel curative-intent therapy for patients with localized hepatocellular carcinoma (HCC). Radiation segmentectomy was developed as a means of addressing two concerns in the treatment of patients with HCC. First, by selectively treating the tumor-bearing hepatic Couinaud segments, the dose of radiation to normal parenchyma is limited and, consequently, the toxicity of radiation segmentectomy is minimized. Second, selective treatment allows for utilization of a higher dose of radiation, which correlates with a higher likelihood of objective response. Radiation segmentectomy hinges on a vital physical property of yttrium-90 (⁹⁰Y): the average penetration of the β-radiation emitted by the decaying ⁹⁰Y is 2.5 mm in tissue.[1] This allows the radiation to be confined to the perfused volume of tumor-bearing liver in which the ⁹⁰Y microspheres are deposited by the catheter, while the rest of the liver remains radiation naive. Additionally, the microembolic nature of ⁹⁰Y microspheres (compared with particles used in chemoembolization) allows for maintaining arterial patency, and avoids tissue ischemia and postembolization syndrome. Radiation segmentectomy may be performed in a subsegmental fashion or, as Riaz et al originally described, ablative radioembolization may be used to treat more than one segment.[2] G.E.J. is a consultant for Boston Scientific Corporation and Genentech. S.A.P. is a consultation for Boston Scientific Corporation and Bristol Meyer Squibb. Publication Date: 11 December 2020 (online) © 2020. Thieme. All rights reserved. Thieme Medical Publishers, Inc. 333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

Complications of portal hypertension, such as variceal hemorrhage and ascites, are associated with significant increases in both mortality and complications during pregnancy. Transjugular intrahepatic portosystemic shunt (TIPS) is a well-established procedure for treating portal hypertension, but the safety of TIPS during pregnancy is largely unknown. In this series, we review five patients who underwent TIPS placement while pregnant and describe their clinical outcomes. Five pregnant patients with cirrhosis and portal hypertension underwent elective TIPS for complications of portal hypertension (four for secondary prevention of variceal bleeding and one for refractory ascites). Outcomes measured were recurrent bleeding episodes or need for further paracenteses during pregnancy, estimated radiation dose to the fetus and gestational age at delivery. All patients were followed after delivery to evaluate technical and clinical success of the procedure. All five patients survived pregnancy and went on to deliver successfully. When TIPS was performed for secondary prevention of variceal bleeding (n = 4), no patients demonstrated variceal bleeding after TIPS placement. When TIPS was performed for refractory ascites (n = 1), no further paracenteses were required. All patients delivered successfully, albeit prematurely. Average radiation dose estimated to the fetus was 16.3 mGy. This series suggests that TIPS can be performed in selective pregnant patients with portal hypertension, with little added risk to the mother or fetus.

Locoregional therapy for hepatocellular carcinoma (HCC) can be challenging in patients with a transjugular intrahepatic portosystemic shunt (TIPS). This study compares safety and imaging response of ablation, chemoembolization, radioembolization, and supportive care in patients with both TIPS and HCC. This retrospective study included 48 patients who had both a TIPS and a diagnosis of HCC. Twenty-nine of 48 (60 %) underwent treatment for HCC, and 19/48 (40 %) received best supportive care (i.e., symptomatic management only). While etiology of cirrhosis and indication for TIPS were similar between the two groups, treated patients had better baseline liver function (34 vs. 67 % Child-Pugh class C). Tumor characteristics were similar between the two groups. A total of 39 ablations, 17 chemoembolizations, and 10 yttrium-90 radioembolizations were performed on 29 patients. Ablation procedures resulted in low rates of hepatotoxicity and clinical toxicity. Post-embolization/ablation syndrome occurred more frequently in patients undergoing chemoembolization than ablation (47 vs. 15 %). Significant hepatic dysfunction occurred more frequently in the chemoembolization group than the ablation group. Follow-up imaging response showed objective response in 100 % of ablation procedures, 67 % of radioembolization procedures, and 50 % of chemoembolization procedures (p = 0.001). When censored for OLT, patients undergoing treatment survived longer than patients receiving supportive care (2273 v. 439 days, p = 0.001). Ablation appears to be safe and efficacious for HCC in patients with TIPS. Catheter-based approaches are associated with potential increased toxicity in this patient population. Chemoembolization appears to be associated with increased toxicity compared to radioembolization.