Intensity-modulated proton therapy for patients with unresectable giant (≥ 10 cm) hepatocellular carcinoma: a retrospective analysis from two high-volume centers.

BACKGROUND

Unresectable giant hepatocellular carcinoma (HCC) has a poor prognosis, and few effective treatment methods are available. In this study, the clinical efficacy of intensity-modulated proton therapy (IMPT) was assessed.

METHODS

A retrospective review was conducted on 71 consecutive patients with giant HCC treated with IMPT at two medical centers from September 2019 to December 2022. The outcomes analyzed included liver and gastrointestinal toxicity, objective response rate (ORR), local control (LC), overall survival (OS), intrahepatic recurrence-free survival (IHRFS), and distant metastasis-free survival (DMFS).

RESULTS

The ORR was 90.2%. The one-year and two-year LC rates were 95.0% and 86.5%, respectively. The one-year and two-year OS rates were 80.0% and 53.8%, respectively, with a median OS of 26.7 months (95% CI 20.8-32.7). At one and two years, the IHRFS rates were 47.4% and 26.0%, and the DMFS rates were 57.7% and 36.8%, respectively. Multivariate analysis indicated that ECOG performance status (p = 0.008) and complete response (CR) after IMPT were independently associated with OS (p = 0.039). Two cases (2.8%) of Grade 3 gastrointestinal toxicity were observed. The incidence of liver failure after IMPT was 12.7%, of which 6.1% were considered radiation related.

CONCLUSIONS

IMPT has potential for treating giant HCC. Despite the excellent LC and ORR, intrahepatic recurrence and distant metastasis remain significant factors affecting survival. More aggressive follow-up and additional therapeutic strategies are necessary, particularly for patients who do not achieve CR after treatment.