Postoperative chemoradiotherapy of pancreatic cancer: What is the appropriate target volume of radiation therapy?

Aims and background: To evaluate the influence of radiation therapy target volume on the treatment outcome of adjuvant chemoradiotherapy for pancreatic cancer after curative resection. Methods: Between February 1987 and July 2001, 70 patients treated with curative resection and adjuvant chemoradiotherapy for pancreatic adenocarcinoma were analyzed. There were 49 males and 21 females, with a median age of 57 years. Whipple's operation was performed in 44 patients, pylorus-preserving pancreaticoduodenectomy in 14, distal pancreatectomy in 9, and subtotal pancreatectomy in 3. Postoperative adjuvant radiotherapy was given up to 40 Gy at 2 Gy per fraction with a two-week planned rest. Intravenous 5-fluorouracil (500 mg/m(2)/day) was given on days 1 to 3 of each split course of radiotherapy. Until 1991, whole pancreas or preoperative tumor volume and retroperitoneal lymph nodes were irradiated (extended field, n = 14). Thereafter, the target volume included the retroperitoneal lymph nodes and the involved pancreatic resection margin (limited field, n = 56). The median follow-up period of all the patients was 16 months (range, 2-99). Results: The overall 2- and 5-year survival rate of all patients was 29.7% and 14.0%, respectively. According to the radiotherapy target volume, the median survival time was 14 months in the extended field group and 16 months in the limited field group (P = 0.65). Conclusions: From the viewpoint of the target volume of radiotherapy, a limited field did not worsen the treatment outcome, although the survival rate was poor in both groups