Stereotactic body radiotherapy for inoperable primary and recurrent cholangiocarcinoma: A single-institution retrospective analysis

A BSTRACT Objectives: Cholangiocarcinoma is a rare and aggressive malignancy with a poor prognosis, particularly in patients who are not candidates for surgical resection. Stereotactic body radiotherapy (SBRT) combines high-dose radiation delivery with meticulous spatial accuracy, allowing for effective local control in a variety of solid tumors. However, clinical data supporting the use of SBRT in cholangiocarcinoma are limited, and this study aimed to investigate the feasibility, safety, and oncologic outcomes of SBRT. Materials and Methods: We retrospectively analyzed 21 consecutive patients with unresectable cholangiocarcinoma who received SBRT between May 2012 and February 2024 at our institution. Eligible patients had no prior liver- or biliary-directed radiotherapy and no distant metastases. Target delineation was performed using four-dimensional computed tomography or breath-hold techniques. SBRT doses ranged from 50 to 60 Gy in 7–10 fractions. Results: The cohort included 16 men and 5 women with a median age of 76 years (range: 58–86). Thirteen patients (62%) had previously undergone surgery and were treated for recurrent disease. At a median follow-up of 9.5 months, the 1-year local control rate was 77.2%. For the entire cohort, the 1-year overall survival and progression-free survival rates were 47.5% (95% confidence interval [CI]: 24.5%–67.4%) and 32.4% (95% CI: 13.4%–53.2%), respectively. Three patients (14.2%) experienced Grade 3 or higher adverse events, consisting of one gastric ulcer and two instances of biliary stricture. Conclusion: SBRT may represent a feasible treatment approach for patients with inoperable cholangiocarcinoma, showing encouraging local control with acceptable toxicity in this small cohort. However, given the study’s limitations, these findings should be regarded as exploratory.