Effect on local control and survival of electron beam intraoperative irradiation for resectable pancreatic adenocarcinoma.

Abstract

To assess the impact on local control and survival of intraoperative radiotherapy (IORT) in resectable pancreatic adenocarcinoma. The outcome of 127 patients surgically treated with curative intent combined with IORT was compared with the therapeutic results of 76 patients treated with surgery as exclusive treatment. Operative mortality and morbidity were similar in IORT and no-IORT patients. In 49 patients with locally limited disease (Stage I-II; LLD), IORT (n = 30) reduced the local failure rate and significantly prolonged time to local failure (TTLF), time to failure (TTF), and overall survival (OS) with respect to surgery alone (n = 19). The multivariate analyses, stratifying patients by age, tumor grade, resection margins, chemotherapy, and external-beam radiotherapy use, confirmed the independent impact of IORT on outcome. In patients with locally advanced disease (Stage III-IVA; LAD), IORT had an impact on local failure rate and on TTLF when combined with beam energies of greater than 6 MeV, whereas no effect on TTF and OS was observed. IORT did not increase operative mortality and morbidity and achieved a significant improvement in local control and outcome in patients with LLD. In patients with LAD, beam energies greater than 6 MeV prolonged TTLF.