Stereotactic body radiotherapy for the treatment of early-stage hepatocellular carcinoma: Evolution from salvage to first-line alternative therapy

The treatment of early-stage hepatocellular carcinoma (Barcelona Clinic Liver Cancer stage 0/A) relies on curative locoregional therapies; however, surgical resection and radiofrequency ablation (RFA) are restricted by patient fitness, tumor size, and anatomical barriers.Stereotactic body radiotherapy (SBRT), once reserved as salvage care for patients ineligible for surgery or ablation, has evolved into an increasingly recognized curative alternative, although comparative evidence for treatment-naive disease remains largely observational.This narrative review compares SBRT with resection and RFA in terms of efficacy, safety, and quality of life in patients stratified by tumor characteristics, liver function, and treatment setting.Observational analyses have shown that resection provides optimal long-term local control for large, operable tumors, whereas RFA is suitable for small, nonperivascular lesions ≤ 2 cm.Largely unconstrained by the heat-sink effect, SBRT appears to offer favorable local control for perivascular, subphrenic, and subcapsular tumors, but whether this is true in treatment-naive disease is currently supported merely by low-level observational (level II) evidence; randomized (level I) evidence currently exists only for recurrent small hepatocellular carcinoma, in which SBRT achieved superior local progression-free survival compared with RFA.Its limitations include transient hepatic toxicity and reduced eligibility for repeat resection after local recurrence.However, heterogeneous fractionation protocols and limited largescale prospective trials remain concerns.SBRT-immunotherapy combinations and artificial intelligence radiomic tools are promising advances in this area; however, much of the supporting evidence is indirect (derived from advanced-stage or noncurative cases), and prospective validation in early-stage disease is required.Finally, we propose a tiered evidence-stratified clinical framework to support individualized multidisciplinary decision-making.