Current evidence and the potential role of proton beam therapy for hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death, and external beam radiation therapy has emerged as a promising approach for managing HCC. Proton beam therapy (PBT) offers dosimetric advantages over X-ray therapy, with superior physical properties known as the Bragg peak. PBT holds promise for reducing hepatotoxicity and allowing safe dose-escalation to the tumor. It has been tried in various clinical conditions and has shown promising local tumor control and survival outcomes. A recent phase III trial demonstrated the non-inferiority of PBT in local tumor control compared to current standard radiofrequency ablation in early-stage HCC. PBT also tended to show more favorable outcomes compared to transarterial chemoembolization in the intermediate stage, and has proven effective in-field disease control and safe toxicity profiles in advanced HCC. In this review, we discuss the rationale, clinical studies, optimal indication, and future directions of PBT in HCC treatment.

Novel paradigm in the treatment of hepatocellular carcinoma: Anticipating breakthroughs with particle therapy

“…They also mentioned PBT had been used successfully in challenging clinical conditions, such as major vascular invasion and re-irradiation. 12 Recently, the first phase III randomized controlled trial demonstrated that PBT was associated with local progression-free survival rates that were comparable to those observed for thermal ablation in patients with recurrent small (<3 cm) HCC. 14 In addition to aforementioned advantage of particle therapy, CIRT possesses further distinctive attributes.…”

“…Particle therapy that can be used in the management of HCC is mainly divided into proton beam therapy (PBT) and carbon ion RT (CIRT). 11,12 The main physical characteristics of particle therapy is the absorbed dose curve shows a slow initial increase with the penetration through matter, than a steep rise to the maximum, known as the Bragg peak, followed by a sharp fall in energy absorption toward the end of the beam range. 13 This unique characteristics can be able to provide a more precise dose delivery to the tumor, while minimizing radiation effect to the surrounding normal tissues effectively.…”

“…In addition, since intrahepatic recurrence is frequent, it is necessary to preserve the uninvolved liver as much as possible during one treatment session to help determine the following treatment at the time of recurrence. In this issue of Clinical and Molecular Hepatology, Lee and Kim 12 demonstrated that PBT was a highly effective local therapeutic option for early-to-advanced stage HCC, with favorable survival outcomes and a low toxicity rate. They also mentioned PBT had been used successfully in challenging clinical conditions, such as major vascular invasion and re-irradiation.…”