Kim TH, Koh YH, Kim BH, et al. - Researchers performed this phase III non-inferiority trial to compare the results of proton beam radiotherapy (PBT) vs radiofrequency ablation (RFA) in patients suffering from recurrent/residual hepatocellular carcinoma (rHCC). Using randomization, patients with rHCC (size <3 cm, number ≤2) were allocated to receive either PBT or RFA based on the Child-Pugh score and tumor stage. The intention-to-treat population included 144 patients receiving PBT (n = 72) and RFA (n = 72). In the PBT arm, six patients switched to RFA, while 19 switched to PBT in the RFA arm. Findings revealed that PBT provided local progression-free survival values that were non-inferior to those for RFA at 2, 3, and 4 years; they were also shown to be tolerable and safe. Radiation pneumonitis (32.5%) and decreased leukocyte counts (23.8%) were the most common adverse events (AEs) for PBT; increased alanine aminotransferase levels (96.4%) and abdominal pain (30.4%) were the most common AEs for RFA. Researchers did not note any grade 4 AEs or mortality.