Supplementary Material for: Efficacy and Safety of Local Liver Radioablation in HCC Lesions within and beyond Limits of Thermal Ablation

Introduction: CT-guided interstitial Brachytherapy (iBT) Radiotherapy has been established in the treatment of liver tumors. With iBT, HCC lesions can be treated beyond the limits of thermal ablation (i.e., size and location). However, a comprehensive analysis of the efficacy of iBT in patients within and beyond thermal ablation limits is lacking.
Materials and Methods: 146 patients with 216 HCC lesions have been analyzed retrospectively. Clinical and imaging follow-up data has been collected. Lesions were evaluated in terms of suitability for thermal ablation or not. The correlation between local tumor control (LTC), time-to-progression (TTP), and overall survival (OS), and clinical and imaging parameters have been evaluated using univariable and multivariable Cox regression analyses.
Results: LTC rates at 12 months, 24 months, and 36 months were 87%,75%, and 73%, respectively. 65% of lesions (n=141) were not suitable for RFA. The median TTP was 13 months, and the median OS was not reached (3-year OS rate: 70%). No significant difference in LTC, TTP, or OS regarding RFA suitability existed. However, in the overall multivariable analysis, lesion diameter > 5 cm was significantly associated with lower LTC (HR: 3.65, CI (1.60-8.31), p=0.002) and shorter TTP (HR: 2.08, CI (1.17-3.70), p=0.013). Advanced BCLC stage, Child-Pugh Stage, and hepatitis B were associated with shorter OS.
Conclusion: iBT offers excellent LTC rates and OS in local HCC treatment regardless of the limits of thermal ablation, suggesting further evidence of its alternative role to thermal ablation in patients with early-stage HCC.