Value of extended resection and intraoperative radiotherapy for resectable pancreatic cancer

Since 1984 intraoperative radiotherapy (IORT) combined with extended resection for pancreatic cancer has been performed in our clinic to prevent local recurrence. Following extended resection, a dose of 30 Gy of 9- to 12-MeV electrons is administered to the operative field, including the paraaortic area from the diaphragm above to the inferior mesenteric artery below. The 5-year survival rate was 15.3% in all 37 cases, 20.2% in patients who had macroscopic tumor clearance, and 16.9% in patients with stage IVa tumor according to the Japanese classification. In autopsies of 10 patients who underwent combined therapy, four had local recurrence enclosed by thick, firm connective tissue. There was no local control recurrence in two patients who underwent noncurative resection. Enhanced local control induced by the combined therapy, however, has only a limited impact on overall survival because of the systemic spread of disease, especially hepatic metastases. At present, as we have no effective treatment for hepatic metastases, it is important to perform an extended resection with IORT on carefully selected patients. The combined therapy may offer the best approach to control local recurrence when dealing with advanced, but not highly advanced, cancer as defined by the stage of tumor. Therefore a combination of IORT and extended resection can have an impact on the results of surgical treatment for pancreatic cancer when anticancer treatment of hepatic metastases is established.