TY - JOUR T1 - Postoperative External Irradiation of Patients with Primary Biliary Tract Cancer: A Multicenter Retrospective Study JF - Anticancer Research JO - Anticancer Res SP - 6231 LP - 6237 VL - 35 IS - 11 AU - KAZUHIKO HAYASHI AU - FUMIAKI ISOHASHI AU - KAZUHIKO OGAWA AU - HIROBUMI OIKAWA AU - HIROSHI ONISHI AU - YOSHINORI ITO AU - MITSUHIRO TAKEMOTO AU - KATSUYUKI KARASAWA AU - MICHIKO IMAI AU - YASUHIRO KOSAKA AU - HIDEYA YAMAZAKI AU - YASUO YOSHIOKA AU - KENJI NEMOTO AU - YASUMASA NISHIMURA AU - THE JAPANESE RADIATION ONCOLOGY STUDY GROUP (JROSG) Y1 - 2015/11/01 UR - http://ar.iiarjournals.org/content/35/11/6231.abstract N2 - Background/Aim: The aim of the present study was to assess clinical outcomes of postoperative radiotherapy for biliary tract cancer patients. Patients and Methods: Clinical results of 187 patients treated with external irradiation in 31 Japanese Institutions between 2000 and 2011 were retrospectively analyzed. The median radiation dose was 50.4 Gy in fractions of 1.8-2 Gy. Results: Two-year actuarial overall survival and locoregional control (LCs) rates were 56% and 68%, respectively. In multivariate analysis, macroscopic residual tumor (R2) and irradiated doses <54 Gy were significant indicators of poor LC prognosis. For patients with complete resection (R0) or microscopic residual tumor (R1), 2-year LCs were 71% for <54 Gy and 83% for ≥54 Gy; doses ≥54 Gy were associated with high long-term LCs. There was no significant difference in acute adverse event rates between <54 Gy and ≥54 Gy. Conclusion: Postoperative irradiation doses of approximately 54 Gy are safe and effective for R0 or R1 resection patients. ER -