Purpose: To evaluate the clinical effectiveness and safety of proton beam therapy (PBT) in advanced hepatocellular carcinoma (HCC) patients with portal vein tumor thrombosis (PVTT).
Patients and methods: Twenty-seven HCC patients with PVTT underwent PBT, including 22 patients with modified International Union Against Cancer (mUICC) stage IVA,five patients with stage IVB primary tumors, and 16 with main PVTT. A median dose of 55 GyE (range, 50-66 GyE) in 20-22 fractions was delivered to a target volume encompassing both the PVTT and primary tumor.
Results: Overall, treatment was well tolerated, with no toxicity of grade ≥ 3. Median overall survival (OS) times in all patients and in stage IVA patients were 13.2 months and 16 months, respectively. Assessments of PVTT response showed complete response in 0 of 27 (0%) patients, partial response in 15 (55.6%), stable disease in 10 (37%), and progressive disease in 2 (7.4%) patients, with an objective response rate of 55.6%. PVTT responders showed significantly higher actuarial 1-year local progression-free survival (LPFS; 85.6% vs. 51.3%), relapse-free survival (RFS; 20% vs. 0%) and OS (80% vs. 25%) rates than nonresponders (p<0.05 each). Multivariate analysis showed that PVTT response and mUICC stage were independent prognostic factors for OS.
Conclusion: Our data suggest that PBT could improve LPFS, RFS, and OS in advanced HCC patients with PVTT and it is feasible and safe for these patients.