A Systematic Review on the Safety and Effectiveness of yttrium-90 Radioembolization for Hepatocellular Carcinoma with Portal Vein Tumor Thrombosis

Background/Aim:Over the past two decades, several advances have been made in the management of patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombosis (PVTT). Yttrium-90 (⁹⁰Y) radioembolization has recently been made a treatment option for patients with HCC and PVTT. However, there is still a need to systematicly evaluate the outcomes of ⁹⁰Y radioembolization for HCC and PVTT. We aimed to assess the safety and effectiveness of ⁹⁰Y radioembolization for HCC and PVTT. We performed a systematic review of clinical trials, clinical studies, and abstracts from conferences that qualified for analysis.Results:A total of 14 clinical studies and three abstracts from conferences including 722 patients qualified for the analysis. The median length of follow-up was 7.2 months; the median time to progression was 5.6 months, and median disease control rate was 74.3%. Radiological response data were reported in five studies, and the median reported value of patients with complete response, partial response, stable disease, and progressive disease were 3.2%, 16.5%, 31.3%, and 28%, respectively. The median survival was 9.7 months for all patients, including the median overall survival (OS) were 12.1, 6.1 months of Child-Pugh class A and B patients, and the median OS were 6.1, 13.4 months of main and branch PVTT patients, respectively. The common toxicities were fatigue, nausea/vomiting, abdominal pain, mostly not requiring medical intervention needed no medication intervention.Conclusions:⁹⁰Y radioembolization is a safe and effective treatment for HCC and PVTT.Key Words: Hepatocellular carcinoma, portal vein tumor thrombosis, radioembolization, toxicity, yttrium-90Portal vein tumor thrombosis (PVTT) occurs in a substantial portion of hepatocellular carcinoma (HCC) patients and in approximately 10%–40% of patients at diagnosis.1,2] PVTT has a profound adverse effect on prognosis, with the median survival time of patients who have unresectable HCC with PVTT being significantly reduced (2–4 months) compared with those without PVTT (10–24 months).1,3] The presence of PVTT also limits the treatment options, with HCC treatment guidelines often considering PVTT a contraindication for transplantation, curative resection, and transarterial chemoembolization (TACE).4,5] Although the presence of PVTT poses a challenging treatment dilemma,1] many treatments of HCC with PVTT have been reported, including surgical,2] TACE,4,5,6,7,8,9] external beam radiotherapy,10] gamma-knife radiosurgery,4] TACE combined with endovascular implantation of an iodine-125 seed strand,11] and transarterial radioembolization.12] However, the optimal treatment for patients with HCC and PVTT remains largely controversial.7] Yttrium-90 (⁹⁰ Y) radioembolization is a locoregional liver-directed therapy that involves transcatheter delivery of particles embedded with the radioisotope ⁹⁰Y. In addition to obliteration of the arterial blood supply, the ⁹⁰Y results in a 50–150 Gy dose of radiation to the tumor tissue, which results in tumor necrosis, including HCC and PVTT.13] It was reported that ⁹⁰Y radioembolization is a safe and effective treatment for patients with HCC and PVTT.6] However, there is still a need to systematically evaluate the outcomes of this treatment modality.The purpose of this study was to comprehensively review the safety and effectiveness of ⁹⁰Y radioembolization for HCC and PVTT.