Safety of adjuvant brachytherapy combined with external beam radiotherapy for proximal bile duct pR1 in perihilar cholangiocarcinoma: a prospective registration study
摘要
Microscopic residual disease (pR1) following resection of perihilar cholangiocarcinoma (pCCA) is associated with high recurrence rates. Adjuvant brachytherapy (BT) combined with external beam radiotherapy (EBRT) is proposed to improve local control; however, contemporary data on treatment-related toxicity are scarce.
MethodsThis prospective registration study included patients with pCCA and isolated pR1 at the proximal bile duct (PBD) margin treated with adjuvant BT and EBRT between January 2017 and December 2021. Primary endpoints were radiation-induced biliary strictures, and severe treatment-related adverse events (TRAEs). Secondary endpoints were overall survival (OS), disease-free survival (DFS) and local recurrence.
ResultsEight patients were eligible of whom six received treatment. Median time from surgery to BT was 39.5 days, with a median follow up of 35.5 months. Early severe TRAEs were infrequent (n = 2). Radiation-induced biliary strictures occurred in four patients and late severe TRAEs were common (n = 16), predominatly by recurrent cholangitis, resulting in one death (n = 1). Four developed recurrence, all at distant sites and no local recurrences. Median DFS was 28.6 months (IQR 10.9–53.5) and median OS 34.3 months (IQR 19.4–39.9).
ConclusionAdjuvant BT combined with EBRT was associated with high rates of severe late TRAEs in resected pCCA. Despite absence of local recurrence, these findings raise concerns regarding routine use outside clinical trials.