Interstitial Brachytherapy for Hepatocellular Carcinoma: Analysis of Prognostic Factors for Overall Survival and Progression-Free Survival and Application of a Risk Stratification Model

Abstract

Introduction: Interstitial brachytherapy (iBT) is an effective treatment for hepatocellular carcinoma (HCC). Identification of prognostic factors is pivotal for patient selection and treatment efficacy. This study aimed to assess the impact of low skeletal muscle mass (LSMM) on overall survival (OS) and progression-free survival (PFS) of iBT in patients with HCC.

Methods: For this single-center study, we retrospectively identified 77 patients with HCC who underwent iBT between 2011 and 2018. Follow-up visits were recorded until 2020. The psoas muscle area, psoas muscle index, psoas muscle density (MD), and the skeletal muscle gauge were assessed on the L3 level on pre-treatment cross-sectional CT scans.

Results: Median OS was 37 months. 42 patients (54.5%) had LSMM. An AFP level of >400 ng/ml (hazard ratio [HR] 5.705, 95% confidence interval [CI]: 2.228-14.606, p = 0.001), BCLC stage (HR 3.230, 95% CI: 0.972-10.735, p = 0.026), and LSMM (HR 3.365, 95% CI: 1.490-7.596, p = 0.002) showed a relevant association with OS. Weighted hazard ratios were used to form a predictive risk stratification model with three groups: patients with low risk (median OS 62 months), intermediate risk (median OS 31 months), and high risk (median OS 9 months). The model showed a good prediction of 1-year mortality, with an AUC of 0.71. Higher MD was associated with better PFS (HR 0.920, 95% CI: 0.881-0.962, p < 0.001).

Conclusion: In patients undergoing iBT for HCC, LSMM is associated with worse OS. A risk stratification model based on LSMM, AFP >400 ng/mL, and BCLC stage successfully predicted patient mortality. The model may support and enhance patient selection.

Keywords: Hepatocellular carcinoma; Interstitial brachytherapy; Low skeletal muscle mass; Overall survival; Prognostic model; Progression-free survival.

Fig. 1

Patient selection algorithm.

Fig. 2

Exemplary illustration of body composition measurements. A line was drawn along the contours of the psoas muscles on both sides. The bilateral areas were added to obtain the psoas muscle area (PMA).

Fig. 3

Kaplan-Meier curve for OS in the overall cohort (a) in the LSMM and non-LSMM group (b), for AFP >400 ng/mL and <400 ng/mL (c), and for BCLC stages (d).

Fig. 4

Kaplan-Meier curves for OS of HCC patients undergoing iBT. Stratification by risk groups. Median OS was 62 months for the low risk, 31 months for the intermediate risk, and 9 months for the high-risk group. The model was confirmed by ROC analysis and 1-year survival with an area under the curve (AUC) of 0.711 (p = 0.01).