Stereotactic body radiation therapy in primary liver tumor: Local control, outcomes and toxicities.

Objective: Stereotactic body radiation therapy (SBRT) is a therapeutic option in the guidelines for liver primaries after standard strategies like surgery or thermoablation have failed. To assess its efficacy and safety, we reviewed all patients treated by SBRT for a hepatocellular carcinoma (HCC) over a six-year period. Methods and materials: The study included all patients treated by SBRT for HCC between April 2015 and November 2021 in the University Cancer Institute at Toulouse-Oncopole. All patients were inoperable and not eligible for thermoablation, or after a failure. All tumor sizes were included and cirrhosis up to Child-Pugh B was accepted. Local control (LC), overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Treatment response was assessed using mRECIST criteria. Toxicity was graded using CTCAE (v4.0). Results: One hundred and nine patients with 118 lesions were treated. Half underwent prior standard treatment. Median dose was 50 Grays in five fractions for most patients. Chronic liver disease represented 90.8 % of cases with a median age of 69 years. Median tumor size was 4.0 cm. Median follow-up was 22.2 months [95 %CI: 15.1-30.4]. LC, OS and PFS at two years were 82.4 % [95 %CI: 71.3; 89.5], 73.2 % [95 %CI: 61.5; 81.8] and 35.8 % [95 %CI: 25.1; 46.7], respectively. Acute toxicities occurred in 20.2 % of patients, including 10.1 % grade 3-4 and 1.8 % grade 5. Late toxicities occurred in 5.5 % of patients including 4.6 % grade 3-4. Grade ≥ 3 toxicity was related to digestive perforation or liver failure. Conclusion: SBRT provides good LC with an acceptable safety profile. It can be used in several settings such as salvage therapy or in combination with validated treatment. Prospective randomized trials are needed to validate SBRT as a standard alternative.