Advanced radiotherapy technique in hepatocellular carcinoma with portal vein thrombosis: Feasibility and clinical outcomes

Background In Thailand, individuals with hepatocellular carcinoma (HCC) who develop portal vein tumor thrombosis (PVTT) have a restricted treatment option because to the extent of the disease, poor underlying liver function, and non-coverage of immuno/targeted therapy. Radiotherapy (RT) plays an increasingly important function in these patients. To investigate the feasibility, efficacy, and adverse event rates, we performed a retrospective analysis of patients with HCC with PVTT who underwent 3-dimensional conformal radiation (3DCRT), intensity-modulated radiation (IMRT), volumetric-modulated radiotherapy (VMAT), and stereotactic body radiotherapy (SBRT) in a single-institution. Objectives To examine clinical results in terms of overall survival (OS), local control (LC), response of primary tumor and PVTT, hepatic and gastrointestinal adverse reaction, and prognosis variables for OS and LC. Materials and methods Between July 2007 and August 2019, non-metastatic HCC with PVTT patients treated with RT were retrospectively reviewed and evaluated. Results The analysis included data from 160 patients. The mean age of the patients was 60.8 years ((95% CI 58.2-62.0). The median diameter of the tumor was 7.7 cm (range: 1-24.5). 85 (54.5%) individuals had PVTT in the main or first branch. At 1.8-10 Gy per fraction, the mean biologically effective dose (BED) as alpha/beta ratio of 10 was 49.6 (95% CI 46.7-52.5) Gy(10). The median survival time was 8.3 (95% CI 6.1-10.3) months. Survival rates at one and two years were 39.6% and 17.1%, respectively. Estimated incidence of local failure using competing risk analysis were 24% and 60% at 1 and 2 years, respectively. The overall response rate was 74%, with an 18.5 percent complete response rate. In multivariate analysis, tumor size, overall response, and radiation dose were all significant prognostic variables for OS. Hepatic unfavorable events of grade 3 and 4 were for 14.1% of the total. There was no occurrences of grade 3-4 gastrointestinal toxicity, either acute or late. Additionally, there were no treatment-related mortality. Conclusions Advanced RT is regarded as a safe and effective therapeutic option for HCC with PVTT. Overall survival was clearly related to tumor size, radiation dose, and tumor/PVTT response. Individuals with BED 56 Gy(10) had significantly better overall survival than patients with BED 56 Gy(10). A prospective randomized trial is required to validate these outcomes in order to corroborate these findings.