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

Abstract BackgroundCholangiocarcinoma (CCA) is a rare malignant tumor of the bile duct epithelium. At first diagnosis, only a minority of patients is 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.MethodsThe monocentric retrospective analysis included 39 patients (31 males, 8 females) with CCA undergoing 53 RT series. Data was 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).ResultsAfter RT, median overall survival (OS) was 10.4 months (mo; 95% confidence interval [CI] 6.6-14.2), median progression-free survival (PFS) was 5.6 mo (95% CI 3-8.2), median duration of local control (DOLC) was 8.9 mo (95% CI 4.7-13.1) and 1-year OS rate was 44.7%. There was a significant difference between patients with and without locoregional lymph node metastasis (OS: 4.3 mo vs. 15.4 mo, p=0.031; PFS: 2.1 mo vs. 11.5 mo, p<0.0005; DOLC: 4.2 mo vs. 12.3 mo, p=0.02). After treatment of a primary tumor, DOLC was about twice as long as in the recurrent situation (10.4 mo vs. 5.4 mo, p=0.032). Conservative therapy significantly elevated the risk of local recurrence compared to radical surgery in univariate (HR 11.04, p=0.004) and multivariate (HR 98.34, p=0.024) analysis. Tomotherapy may be advantageous with respect to local recurrence and survival.Side effects were mostly classified as grade I-II according to CTCAE. There were 10 toxicities of grade III and 4 of grade IV, all affecting blood parameters. Termination of RT and increased glutamic pyruvic transaminase (GPT) were significantly less frequent after stereotactic body radiation therapy and hypofractionation.ConclusionRT can achieve local control in patients with CCA. However, since overall prognosis remains poor, effective combination therapies are needed. Toxicities of RT are manageable but require close clinical and laboratory follow-up.