Effect of external beam radiotherapy on patency of uncovered metallic stents in patients with inoperable bile duct cancer

Background Although biliary decompression with metallic stenting is the preferred treatment for inoperable bile duct cancer (BDC), maintenance of patency is still unsatisfactory. We tried to assess the effectiveness and safety of external beam radiotherapy (EBRT) for prolonging stent patency in patients having uncovered metallic stents. Method We retrospectively reviewed 50 patients who received endoscopic stenting, of whom 18 received EBRT (RT group) and 32 did not (non-RT group). Results No difference was found in baseline characteristics between the two groups. Although stent patency was longer in the RT group than that in the non-RT group (140.7±51.3 vs 136.4±34.9 days, P=0.94), the difference was not statistically significant. There were a lower rate of stent occlusion (27.8% vs 50.0% of patients, P=0.12) and a longer overall survival (420.1±73.2 vs 269.1±41.7 days, P=0.11) in the RT group than in the non-RT group, and the difference again was not statistically significant. The development of adverse reactions did not differ (55.6% vs 53.1% of patients, P=0.91). There was no serious adverse reaction in both groups (P=0.99). Conclusions EBRT did not significantly improve stent patency in patients with inoperable BDC having uncovered metallic stents. However, EBRT was safe. Future trials with refined protocols for better efficacy are expected.