Intraoperative radiation therapy in resected pancreatic carcinoma: long-term analysis.

Purpose: The combination of external radiotherapy (RT) plus intraoperative radiotherapy (IORT) in patients with pancreatic cancer is still debated. This study presents long-term results (minimum follow-up, 102 months) for 26 patients undergoing integrated adjuvant RT (external RT+IORT).
Methods and Materials: From 1990 to 1995, a total of 17 patients with pancreatic cancer underwent IORT (10 Gy) and postoperative external RT (50.4 Gy). Preoperative "flash" RT was included for the last 9 patients. The liver and pancreatic head received 5 Gy (two 2.5-Gy fractions) the day before surgery. In the subsequent period (1996-1998), 9 patients underwent preoperative concomitant chemoradiation (39.6 Gy) with 5-fluorouracil, IORT (10 Gy), and adjuvant chemotherapy.
Results: Preoperative chemoradiation was completed in all patients, whereas postoperative therapy was completed in 13 of 17 patients. All 26 patients underwent pancreatectomy (25 R0 and one R1 resections). One patient died of postoperative complications (3.8%) not related to IORT. The 9 patients undergoing concomitant chemoradiation were candidates for adjuvant chemotherapy; however, only 4 of 9 underwent adjuvant chemotherapy. At last follow-up, 4 patients (15.4%) were alive and disease free. Disease recurrence was documented in 20 patients (76.9%). Sixteen patients (61.5%) showed distant metastasis, and 5 patients (19.2%) showed local recurrence. The incidence of local recurrence in R0 patients was 4 of 25 (16.0%). The overall 5-year survival rate was 15.4%. There was significant correlation with overall survival of tumor diameter (p=0.019).
Conclusions: The incidence of local recurrence in this long follow-up series (19.2%) was definitely less than that reported in other studies of adjuvant RT (approximately 50%), suggesting a positive impact on local control of integrated adjuvant RT (IORT+external RT).