Supplementary Material for: Development and Validation of a Nomogram for Patients with Nonmetastatic BCLC Stage C Hepatocellular Carcinoma after Stereotactic Body Radiotherapy

Background: Stereotactic body radiotherapy (SBRT) is an emerging treatment modality for hepatocellular carcinoma (HCC) with promising outcome. However, appropriate survival prediction models are scarce. This study aimed to develop a simple and clinically useful prognostic nomogram for patients with nondistant metastatic Barcelona Clinic Liver Cancer (BCLC) stage C HCC undergoing SBRT. Methods: The data were based on a prospective multi-institutional registry enrolling 246 patients with nondistant metastatic BCLC stage C HCC treated with SBRT between January 1, 2008 and December 31, 2016. They were randomly divided into two subsets: 164 into the development cohort and 82 into the validation cohort. We identified and included prognostic factors for survival to derive a nomogram in the development cohort. The predictability of the nomogram was evaluated in the validation cohort. The area under the receiver operating characteristic curve (AUROC) and the calibration plot were used to evaluate the performance of the nomogram. Results: The median survival was 13.5 months, with 1- and 2-year overall survival (OS) rates of 55.0 and 32.9%, respectively. Number of tumors, largest tumor size, macrovascular invasion, Child-Turcotte-Pugh class, and biologically effective dose were significantly associated with OS (p < 0.05). These predictors were included to develop a nomogram with an AUROC of 0.77 (0.73–0.87). The prediction model was well calibrated in the validation cohort. The OS for patients who were divided by their risk scores differed significantly (p < 0.001). Conclusions: The nomogram we generated had discriminatory and satisfactory predictability for OS among nonmetastatic BCLC stage C HCC patients treated with SBRT. It demands further validations with cross-country data to confirm its worldwide usefulness.