Stereotactic body radiotherapy and gemcitabine for locally advanced pancreatic cancer.

Abstract

Patients with nonmetastatic locally advanced unresectable pancreatic cancer have a dismal prognosis. Conventional concurrent chemoradiotherapy requires 6 weeks of daily treatment and can be arduous. We explored the safety and effectiveness of a 3-day course of hypofractionated stereotactic body radiotherapy (SBRT) followed by gemcitabine in this population. A total of 36 patients with nonmetastatic, locally advanced, unresectable pancreatic cancer with ≥12 months of follow-up were included. They received three fractions of 8, 10, or 12 Gy (total dose, 24-36 Gy) of SBRT according to the tumor location in relation to the stomach and duodenum, using fiducial-based respiratory motion tracking on a robotic radiosurgery system. The patients were then offered gemcitabine for 6 months or until tolerance or disease progression. With an overall median follow-up of 24 months (range, 12-33), the local control rate was 78%, the median overall survival time was 14.3 months, the median carbohydrate antigen 19-9-determined progression-free survival time was 7.9 months, and the median computed tomography-determined progression-free survival time was 9.6 months. Of the 36 patients, 28 (78%) eventually developed distant metastases. Six patients (17%) were free of progression at the last follow-up visit (range, 13-30 months) as determined by normalized tumor markers with stable computed tomography findings. Nine Grade 2 (25%) and five Grade 3 (14%) toxicities attributable to SBRT occurred. Hypofractionated SBRT can be delivered quickly and effectively in patients with nonmetastatic, locally advanced, unresectable pancreatic cancer with acceptable side effects and minimal interference with gemcitabine chemotherapy.