This retrospective single-center study included 69 tumors in 55 patients treated by RF ablation and 136 tumors in 99 patients treated by MW ablation between 2001 and 2013. RF and MW ablation devices included straight 17-gauge applicators. Overall survival and rates of local tumor progression (LTP) were evaluated using Kaplan-Meier techniques with Cox proportional hazard ratio (HR) models and competing risk regression of LTP.
RF and MW cohorts were similar in age (P = .22), Model for End-Stage Liver Disease score (P = .24), and tumor size (mean 2.4 cm [range, 0.6–4.5 cm] and 2.2 cm [0.5–4.2 cm], P = .09). Median length of follow-up was 31 months for RF and 24 months for MW. Rate of LTP was 17.7% with RF and 8.8% with MW. Corresponding HR from Cox and competing risk models was 2.17 (95% confidence interval [CI], 1.04–4.50; P = 0.04) and 2.01 (95% CI, 0.95–4.26; P = .07), respectively. There was improved survival for patients treated with MW ablation, although this was not statistically significant (Cox HR, 1.59 [95% CI, 0.91–2.77; P = .103]). There were few major (≥ grade C) complications (2 for RF, 1 for MW; P = .28).
Treating HCC percutaneously with RF or MW ablation was associated with high primary efficacy and durable response, with lower rates of LTP after MW ablation.