Radiofrequency ablation of subcapsular versus nonsubcapsular hepatocellular carcinomas ≤ 3 cm: analysis of long-term outcomes from two large-volume liver centers

Abstract

Objectives To compare the safety and efficacy of RFA for single HCCs <= 3 cm in subcapsular versus nonsubcapsular locations using a propensity score matched analysis.,Materials and methods This retrospective study included patients with solitary HCCs <= 3 cm in size who underwent percutaneous RFA from 2005 to 2015 as initial treatment at two large-volume liver centers. Patients were divided into two groups, consisting of those with subcapsular and nonsubcapsular tumor locations. Complications, local tumor progression (LTP), and overall survival ( OS) were compared in these two groups before and after propensity score matching (PSM).,Results The study population consisted of 964 patients ( 712 men [74%]) of mean age 58.3 years. Of these 964 patients, 561 (58%) had nonsubcapsular and 403 (42%) had subcapsular HCCs. PSM generated 402 pairs of patients. Major complication rate was low, but significantly higher in the subcapscular group (p = 0.047). Rates of technical effectiveness in these two groups were 99% and 98%, respectively (p = 0.315). However, during follow-up, cumulative 1-, 3-, 5-, and 10-year LTP and OS rates did significantly differ in both entire and PSM cohorts, resulting in the latter 8%, 15%, 20%, and 26% in the nonsubcapsular group vs. 13%, 24%, 30%, and 31% in the subcapsular group ( p = 0.015), and 99%, 91%, 80%, and 59% vs. 98%, 85%, 73%, and 50% in the two groups (p = 0.004), respectively.,Conclusion Rates of major complications, LTP, and OS differed significantly following first-line RFA treatment of single HCCs <= 3 cm in favor of the nonsubcapsular locations.,Clinical relevance statement This large-scale study provides evidence that radiofrequency ablation for small (<= 3 cm) hepatocellular carcinomas is safer and more effective in nonsubcapsular location than in subcapsular location.,