Radiotherapeutic strategies for hepatocellular carcinoma with portal vein tumour thrombosis in a hepatitis B endemic area

Abstract

Background & Aims: This nationwide, multicenter study investigated treatment outcomes as well as the optimal radiother- apeutic strategy in patients with hepatocellular carcinoma (HCC) and portal vein tumour thrombosis (PVTT). Methods: We retrospectively reviewed the records of 985 patients who received radiotherapy (RT) for PVTT. The median equivalent RT dose was 48.75 Gy. Combined treatment, defined as liver-directed treatments performed within a month of RT, was admin- istered to 657 patients (66.7%). The PVTT and primary tumour were irradiated in 413 patients (41.9%), and PVTT only was targeted in 572 patients (58.1%). Results: The response rate of the PVTT was 51.8%, and RT responders had a significantly longer survival than non-responders (15.2 vs. 6.9 months). Equivalent RT dose and combined treatment predicted response of PVTT. The median overall survival (OS) was 10.2 months. Multivariate analysis revealed the equivalent RT dose ˃45 Gy and combined treatment as significant positive factors for OS. In the propensity score matching analysis, the combined treat- ment group had better OS than the no combined treatment group, whereas the OS of the PVTT + primary tumour group did not differ significantly from that of the PVTT only group. Conclusion: The equivalent RT dose ˃45 Gy, given in combi- nation with other treatments, provided better PVTT control and OS. The optimal RT volume is suggested for either PVTT + primary or PVTT only. Taken together, multimodal treatment with equivalent RT dose higher than 45 Gy is recom- mended for patients with HCC and PVTT.