Prognostic Factors in Advanced Hepatocellular Carcinoma (HCC) of 10cmTreated with Stereotactic Body Radiotherapy (SBRT)

Abstract

Purpose: The role of stereotactic body radiotherapy (SBRT) is evolving in patients with hepatocellular carcinoma (HCC). This study is to evaluate the efficacy of SBRT in advanced HCC population and identify the predictive factors of overall survival. Patients and Methods: This is a retrospective study that included all patients treated with SBRT from 2006 to 2017. Data were retrieved from a prospective collected database. All patients had advanced HCC >5 cm ineligible for curative interventions and Child-Pugh (CP) score A5 to B7. The SBRT dose range was 4Gy in 6 to 10 fractions. The primary endpoint is overall survival (OS). Results: A total of 156 patients were evaluable. Underlying liver disease was hepatitis B in 80.1% of patients. The median tumor size was 12.2 cm (range:5.0–25.7 cm). Tumor vascular thrombosis was present in 48.1% and extra-hepatic disease was present in 31.4%; 17.3% had CP class B disease. The median total equivalent dose in 2Gy per fraction (EQD2, a/b = 10) was 32.7Gy (4Gy in 7 fractions). The median OS and 1-year overall survival rate and local control rate was 44.2%, (95% Cl:36.4%-52.0%) and 83.5 % (95% Cl:76.7%–90.4%) respectively. Under multivariate analysis, extra-hepatic metastases (hazard ratio HR:2.1, range:1.38–3.3, p = 0.001), AFP level (HR:2.6, range 1.75–4.06, p < 0.001), number of lesions (HR:2.4, range 1.34–40.29), and post-SBRT therapy (HR: 0.32, range:0.17–0.6, p < 0.001) were independently predicting OS. Treatment responder of SBRT (CR+PR) was independently associated with better local control (HR:2.8, range:1.0–5.5, p = 0.04) and a trend towards improved OS (HR:1.4, range: 0.95–2.09, p = 0.09). Conclusion: In advanced HCC population with median size of tumor >10 cm, SBRT provides favorable survival outcome. Patients who responded to SBRT and received further systemic therapy had better survival. Further study to combine both is warranted.