Proton Beam Radiotherapy as Treatment Alternative to TACE for Patients With Hepatocellular Carcinoma

According to a randomized, controlled trial, patients with hepatocellular carcinoma treated with proton beam radiotherapy or transarterial chemoembolization (TACE) had similar overall survival (OS), however the progression-free survival (PFS) and local control (LC) were improved in those treated with proton beam radiotherapy.

David A. Bush, MD, Loma Linda University Medical Center, Loma Linda, California, and coauthors stated, “For tumors within the liver, multiple treatment planning studies have been conducted that show improved dose delivery characteristics with proton beams when compared to photon-based techniques.”

For patients with hepatocellular carcinoma confined to the liver who are not eligible for resection or thermal ablation, TACE is the primary treatment option. However, phase 2 data have shown promising local control rates and survival rates comparable to TACE with proton beam radiotherapy.

In this trial, 76 patients with untreated hepatocellular carcinoma who met Milan or San Francisco transplant criteria were randomized to receive either proton beam radiotherapy (15 fractions over 3 weeks, total dose, 70.2 Gray; n = 36) or TACE (repeated until maximal response; n = 40). The primary outcome measure was OS, with PFS, LC, toxicity, and cost as secondary measures.

Of the 76 total patients, 74 were evaluable for outcome measures. The 2-year OS in the proton beam radiotherapy arm was 65% vs 68% in the TACE arm (P = .80). The median PFS was improved in the proton beam radiotherapy arm compared to the TACE arm (not reached vs 12 months; P = .002), as was LC (hazard ratio [HR], 5.64; 95% confidence interval [CI], 1.76 to 17.9; P = .003). There was a 28% cost saving for mean cost per patient for treatment and posttreatment in the proton beam radiotherapy arm compared with the TACE arm. Additionally, the days of post-treatment hospitalization were 24 in the proton beam radiotherapy arm vs 166 in the TACE arm (P < .001).

Dr Bush et al wrote, “This trial is considered a negative trial based on the primary outcome objective of improved overall survival not being realized,” however they went on to add, proton beam radiotherapy “produced significantly improved LC and PFS along with reduced incidence of posttreatment hospitalization indicating superior secondary outcomes and decreased toxicity.” These data combined with “fewer courses of treatment and decreased posttreatment medical care producing a cost savings” indicate proton beam radiotherapy as “an alternative to TACE for patients with [hepatocellular carcinoma] meeting criteria in this trial,” Dr Bush et al concluded.

Source:

Bush DA, Volk M, Smith JC, et al. Proton beam radiotherapy versus transarterial chemoembolization for hepatocellular carcinoma: Results of a randomized clinical trial. Cancer. Published on July 28, 2023. doi:10.1002/cncr.34965