Proton beam radiotherapy matches radiofrequency ablation in recurrent/residual HCC

Proton beam radiotherapy (PBT) is a tolerable and safe approach to recurrent/residual hepatocellular carcinoma (rHCC) that yields comparable local progression-free survival (LPFS) rates to radiofrequency ablation (RFA), reports a recent study.

A total of 144 rHCC patients (tumour size < 3cm, number ≤ 2) participated in the study and were randomly allocated to PBT (n=72; median age, 60 years; 84.7 percent male) or RFA (n=72; median age, 61.5 years; 81.9 percent male) groups. Treatment cross-over was allowed in patients where the treatment assignment was technically infeasible. The primary outcome of interest was 2-year LPFS, and a per-protocol noninferiority margin of 15 percent was set.

After considering crossovers, the per-protocol analysis included 80 and 56 patients who received PBT and RFA, followed for a median of 51.6 and 50.7 months, respectively.

The 2-year per-protocol LPFS rate in the PBT group was 94.8 percent, while RFA conferred a corresponding rate of 83.9 percent. The resulting difference value was 10.9 percent, which met the criteria for noninferiority.

Similarly, in an intention-to-treat analysis, the 2-year LPFS rates for PBT and RFA were 92.8 percent and 83.2 percent, respectively, which also achieved noninferiority. Hazard ratios were likewise not significantly different between the treatment arms.

In terms of safety and tolerability, both groups displayed comparable incidence rates of leukopaenia, thrombocytopaenia, and hyperbilirubinaemia, and hypoalbuminaemia. Grade 3 adverse events occurred significantly more frequently in patients who received RFA (16.1 percent vs 0 percent; p<0.001), but all episodes were transient; all patients recovered.

There were no cases of treatment-related late hepatic failure and death without evidence of disease progression in either group.