HIGH-DOSE PREOPERATIVE EXTERNAL-BEAM AND INTRAOPERATIVE IRRADIATION FOR LOCALLY ADVANCED PANCREATIC-CANCER

Purpose: To analyze results of high-dose preoperative external beam ir radiation followed by surgical exploration and intraoperative radiatio n therapy in patients with unresectable pancreatic cancer. Methods and Materials: From December 1983 through December 1990, 27 patients with primary unresectable but localized pancreatic adenocarcinoma received high-dose (50 to 54 Gy) external beam irradiation with or without con comitant bolus 5-fluorouracil followed by surgical exploration and int raoperative electron beam irradiation (20 Gy) at the Mayo Clinic. Resu lts: Local control was achieved in 21 of 27 (78%) patients. Actuarial local control at 1, 2, and 5 years was 86%, 68%, and 45%, respectively . In 19 (70%) of the 27 patients, distant metastasis developed, and pe ritoneal or liver progression (or both) was found in 14 (52%). The act uarial distant metastasis rate at 2 and 5 years was 69% and 83%, respe ctively. Median survival from the date of diagnosis was 14.9 months. A ctuarial 2- and 5-year overall survival was 27% and 7%, respectively. These survival rates are higher (p = 0.001) than the 6% and 0% actuari al 2- and 5-year survival observed in 56 patients who underwent intrao perative radiation therapy followed by post-operative high-dose extern al beam treatment at our institution. Conclusion: Administering the fu ll component of external beam irradiation before exploration and intra operative radiation therapy may be more appropriate because it allows better patient selection. Unfortunately, altered patient selection was not effective in decreasing the relative risk of abdominal failure. B ecause effective systemic chemotherapy does not currently exist, whole abdominal irradiation alone or in combination with chemotherapy warra nts evaluation.