The histopathological effect of preoperative irradiation for the adenocarcinoma of the periampullary region

For 12 cases of adenocarcinoma of the periampullary region (pancreas = 6, biliary tract = 4 and papilla of Vater = 2), preoperative irradiation and following pancreaticoduodenectomy was performed. They received 50 Gy/25 FRX/5 W of localized field (11 x 11 cm). The tumor size decreased from 3.1 ± 0.8 cm to 1.6 ± 0.7 cm preoperatively. Neither new lesion nor severe complication was observed. Histological examination of the resected specimen showed that fibrous connective tissue surrounded the cancer tissue (1.2 ± 0.8 cm) and which had various ratios of viable and non-viable cancer cells. According to Ohboshi's classification, 6 cases were classified as IIa, 5 cases as IIb and one case as III. The non-viable cells were likely to locate at the periphery in 10 cases, but other 2 cases (IIa) with chronic pancreatitis in the noncancerous tissue showed homogeneous distribution of viable and non-viable cells. Since this method did not make the operation difficult, we can expect that preoperative irradiation will improve the operative curability and prolong the survival period. (author)