Effect of intraoperative radiotherapy on pancreatic carcinoma: histopathological findings from autopsy cases.

Histopathological examinations of 18 necropsy patients with pancreatic carcinoma who died after receiving intraoperative radiotherapy (IOR) revealed the following: 1) Cancer cells were suspected of remaining in the periphery of the irradiated areas. 2) Thickening of intima of small arteries, some of which were obstructed, was found in the tumor tissues. 3) Highly degenerated nerve fibers were observed within the necrotic or viable tumor tissues. These findings provide evidence of the effects of IOR, while they also demonstrate the problems encountered in improving this treatment and the necessity of a complementary therapy for complete local control of pancreatic cancer by IOR.