Purpose: A joint analysis of data from five contributing centers within the ISIORT-Europe program was performed to investigate the main contributions of intra-operative radiotherapy (IORT) to the multidisciplinary treatment of pancreatic cancer.
Materials and methods: Patients with a histologic diagnosis of carcinoma of the pancreas, with an absence of distant metastases, undergoing surgery with radical intent and IORT were considered eligible for participation in this study.
Results: From 1985 to 2006, a total of 270 patients were enrolled in the study from five European institutions. Surgery was performed in 91.5% of cases and complicated by adverse events in 59 cases. External radiotherapy (ERT) preceded surgery in 23.9% of cases. One-hundred and six patients received further ERT. After surgery + IORT, median follow-up was 96 months (range 3-180). Median local control was 15 months, 5-year local control was 23.3%. Median overall survival was 19 months, while 5-year survival was 17.7%. A significantly greater local control and survival were observed in patients undergoing preoperative radiotherapy (LC: median not reached; OS: median 30 months) compared to patients treated with postoperative ERT alone (LC: median 28 months; OS: median 22 months), and to patients submitted to IORT exclusively (LC: median 8 months; OS: median 13 months) (p < 0.0001).
Conclusion: From this joint analysis emerges the fact that preoperative radiotherapy increases the effects of IORT in terms of local control and overall survival. The 5-year local control of 23.3% confirms the beneficial "sterilizing" effect of IORT on the tumor bed.