Intrahepatic Biliary Stricture After Carbon-Ion Radiotherapy: A Review

March 23, 2026 Dr. Michael Lee – Health Editor Health

A patient undergoing carbon-ion radiotherapy (C-ion RT) for hepatocellular carcinoma (HCC) developed fatal, refractory radiation-induced biliary stenosis (RIBS), according to a case report published by Cureus. The case highlights a potentially lethal complication associated with the treatment, particularly when tumors are located near the hepatic hilum.

Carbon-ion radiotherapy is an established treatment modality for HCC, but carries inherent risks. The report details a case where a patient, treated with C-ion RT for a tumor in proximity to the hepatic hilum, experienced progressive biliary stenosis during long-term follow-up. Despite interventions, the condition proved refractory, ultimately contributing to the patient’s death.

Researchers at Yamagata University Faculty of Medicine, Japan, have been investigating adverse events following carbon-ion radiotherapy for HCC. A retrospective study analyzing 103 patients undergoing CIRT (60 Gy/4 fractions) examined the timing, frequency, and grade of adverse events, with a specific focus on risk factors for biliary stricture. The study, published in Cancers in July 2025, aimed to improve patient management and follow-up strategies after CIRT.

The research identified biliary stricture as a significant adverse event. The study’s conceptualization, methodology, validation, formal analysis, data curation, and writing were led by Keita Maki, with contributions from Hiroaki Haga, Tomohiro Katsumi, Kyoko Hoshikawa, Fumiaki Suzuki, Fumio Uchiyama, and Yu Ueno. The team’s operate suggests a need for careful monitoring of patients undergoing C-ion RT, particularly those with tumors near the hepatic hilum, to detect and manage potential biliary complications.

Radiation-induced biliary stenosis is a known, though infrequent, complication of radiotherapy for HCC. The case report emphasizes the severity of RIBS when it becomes refractory to treatment. The study from Yamagata University suggests a need to further investigate the risk factors associated with high-grade adverse events, including biliary stricture, following CIRT.