Efficacy and Dose-Response Relationship of Stereotactic Body Radiotherapy for Abdominal Lymph Node Metastases from Hepatocellular Carcinoma

BACKGROUND: The objective of this study was to investigate the treatment efficacy of stereotactic body radiotherapy (SBRT) and evaluate the influence of radiation dose on local control and survival in patients with abdominal lymph node metastases (LNM) from hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Between 2010 and 2020, data of 148 patients with HCC with abdominal LNM, including 114 who underwent SBRT and 34 who received conventional fractionation radiation therapy (CFRT), were collected. A total radiation dose of 28-60 Gy was delivered in 3-30 fractions, with a median biologic effective dose (BED) of 60 Gy (range, 39-105 Gy). Freedom from local progression (FFLP) and overall survival (OS) rates were analyzed. RESULTS: With a median follow-up of 13.6 months (range, 0.4-96.0 months), the 2-year FFLP and OS rates of the entire cohort were 70.6% and 49.7%, respectively. Median OS of the SBRT group was longer than the CFRT group (29.7 vs. 9.9 months, P = .007). A dose-response relationship was observed between local control and BED in either the entire cohort or the SBRT subgroup. Patients who received SBRT with a BED ≥60 Gy had significantly higher 2-year FFLP and OS rates than those who received a BED <60 Gy (80.1% vs. 63.4%, P = .004; 68.3% vs. 33.0%, P < .001). On multivariate analysis, BED was an independent prognostic factor for both FFLP and OS. CONCLUSIONS: SBRT achieved satisfactory local control and survival with feasible toxicities in patients with HCC with abdominal LNM. Moreover, the findings of this large series suggest a dose-response relationship between local control and BED.