Stereotactic body radiation therapy as bridging or downstaging therapy for hepatocellular carcinoma in liver transplant candidates: A systematic review and meta-analysis.

Bridging and downstaging are indications for locoregional therapy (LRT) in hepatocellular carcinoma (HCC) within the context of liver transplantation (LT). Stereotactic body radiation therapy (SBRT) is an emerging LRT modality in these settings. We conducted a systematic review and meta-analysis to assess the efficacy and safety of SBRT as bridging or downstaging therapy. A comprehensive search of PubMed, Embase, and Cochrane Library was performed through July 21, 2025. We included randomized and non-randomized studies evaluating SBRT in LT candidates or potential candidates with HCC, reporting outcomes such as radiologic or pathologic response, overall/disease-free survival, waitlist dropout, pre-LT/post-LT mortality, recurrence, adverse events, radiation-induced liver disease, fibrosis at LT, and liver function decline. Single-arm meta-analyses using random-effects models were performed to estimate pooled proportions with 95% CIs. Risk of bias was assessed using the MINORS tool. Nineteen studies (664 lesions in 476 patients; 381 underwent LT) were included. SBRT demonstrated favorable radiological and pathological response rates when used as bridging or downstaging therapy in liver transplant candidates with HCC, with a pooled radiological objective response (CR + PR) of 61.2% and pathological response of 83.8%. The 5-year overall survival and disease-free survival rates were 76.8% and 71.3%, respectively. Adverse events were infrequent, with grade ≥3 toxicities occurring in only 1.2% of patients. Subgroup analysis restricted to bridging-only studies yielded comparable trends. SBRT is a safe and effective bridging or downstaging therapy for HCC patients awaiting LT.