The Role of Postoperative Radiation Therapy in Extrahepatic Bile Duct Cancers / 대한방사선종양학회지

ABSTRACT

PURPOSE: The goal of this study was to determine the role of postoperative radiation therapy in extrahepatic bile duct cancers. MATERIALS AND METHODS: Between 1997 and 2001, 41 patients with extrahepatic bile duct cancer having undergone surgical resection were retrospectively analyzed. Of the 41 patients, 22 were treated by surgery alone (Group I) with remaining 19 treated by surgery and postoperative radiation therapy (Group II). A gross total surgical resection with pathologically negative margins was performed in 11 of the patients (50%) in Group I, and in 7 of the patients (36.8%) in Group II. There were no significant differences in the disease stage, surgical procedure or pathological characteristics of the two groups. The patients in group II received 45~54 Gy (median 50.4 Gy) of external beam radiation therapy to the tumor bed and draining nodal area. RESULTS: The local failure rate was significantly higher in group I (54.5%) than in group II (15.8%)(p=0.010). Of the 12 failed patients in Group I and the 3 failed patients in group II, 7 and 3 had a positive resection margin. The overall 3-year survival rates were 38.3 and 38.9% and the 3-year disease free survival rates were 18.8 and 26.3% in groups I and II, respectively. However, the patients with positive resection margins who received adjuvant radiation therapy had higher 3-year overall survival rates than those with surgery alone (36.4% vs. 24.2%, p=0.06), and 3-year disease free survival rate was significantly higher in the group II patients who had positive margins compared with those in group I (25.0% vs. 18.2%, p=0.04). CONCLUSION: Postoperative adjuvant radiation therapy appeared to reduce the incidence of local failure in patients with extrahepatic bile duct cancer, and might improve the survival rate in the patients with positive resection margins.