Repeated stereotactic ablative radiotherapy using CyberKnife for patients with hepatocellular carcinoma

Abstract

Background and aim: This study aimed to evaluate the outcomes and toxicities of repeated stereotactic ablative radiotherapy (SABR) in hepatocellular carcinoma (HCC).

Methods: Fourteen HCC patients with local recurrence (18 lesions) after liver SABR received repeated radiotherapy with SABR using CyberKnife. No patients experienced radiation-induced liver disease after the first SABR course. The median first SABR dose was 41 Gy (range, 34-60 Gy); the median second SABR dose, 40 Gy (range, 25-50 Gy); and the median interval, 12.9 months. Local recurrence was divided into in-field recurrence and out-field recurrence.

Results: Objective responses were observed in 11 tumors (61.1%), including five tumors (27.8%) with complete responses. Intrahepatic out-field failure was the main cause of treatment failure (7 of 14 patients). In-field failure had developed in 1 of 18 tumors (5.6%), resulting in a 2-year in-field failure-free rate of 88.2%. The median time to progression was 14.0 months, with 1- and 2-year progression-free survival rates of 68.6% and 42.9%, respectively. One- and two-year overall survival rates were 76% and 59.1%, respectively. Of the 14 patients, one developed radiation-induced liver disease and three showed progression of the Child-Turcotte-Pugh class after the second SABR course. Other toxicities were generally mild and tolerable.

Conclusion: Repeated SABR in selected HCC patients is feasible with acceptable toxicity.

Keywords: CyberKnife; hepatocellular carcinoma; repeated radiotherapy; stereotactic ablative radiotherapy.