Examining the use of radiation therapy for cholangiocarcinoma: benefits through modern techniques

Background Cholangiocarcinoma (CCA) is a rare malignant tumor of the bile duct epithelium. At first diagnosis, only a minority of patients are eligible for surgery, which is regarded as the only curative treatment. This study examines the role of radiation therapy (RT) and chemoradiotherapy (CRT) in the definitive and adjuvant treatment situation. Methods The monocentric, retrospective analysis included 39 patients with CCA undergoing 53 RT courses. Data were collected from January 2005 to September 2018. There were 11 cases of CRT, 6 of which were definitive. Surgery was either palliative (n = 6) or radical (n = 15). Results After RT, the median overall survival (OS) was 10.4 months (m), median progression-free survival was 5.6 m, and median duration of local control (DOLC) was 8.9 m. There was a significant difference in survival between patients with and without locoregional lymph node metastasis (OS: 4.3 vs. 15.4 m, p = 0.031). After treatment of a primary tumor, DOLC was about twice as long as in the recurrent situation (10.4 vs. 5.4 m, p = 0.032). Conservative therapy significantly elevated the risk of local recurrence compared to radical surgery in univariate and multivariate analyses. Side effects were mostly classified as mild to moderate. Termination of RT and increased alanine aminotransferase were significantly less frequent after stereotactic body radiation therapy and hypofractionation. Conclusion RT can achieve local control in patients with CCA. Toxicities of RT are manageable but require close clinical and laboratory follow-up.