Stereotactic body radiation therapy for reirradiation of localized adenocarcinoma of the pancreas

Background: Local control rates are poor in the treatment of pancreatic cancer. We investigated the role of hypofractionated stereotactic body radiation therapy (SBRT) for salvage or boost treatment after conventional doses of external beam radiation therapy. Methods: All patients treated with SBRT for pancreatic adenocarcinoma at Georgetown University from June 2002 through July 2007 were examined. Eligible patients had prior external beam radiation therapy to the pancreas. Treatment parameters and clinical and radiographic follow-up were evaluated. Results: Twenty-eight patients were identified who received SBRT after a median prior external beam radiotherapy dose of 50.4 Gy. The median patient age was 63 years old and the median follow-up was 5.9 months. Twelve of fourteen (85.7%) evaluable patients were free from local progression, with three partial responses and nine patients with stable disease. Toxicity consisted of one case of acute Grade II nausea/vomiting, and two cases of Grade III late GI toxicity. The median overall survival was 5.9 months, with 18% survival and 70% freedom from local progression at one year. Conclusions: Hypofractionated SBRT reirradiation of localized pancreatic cancer is a well-tolerated treatment. Most patients are free from local progression, albeit with limited follow-up, but overall survival remains poor.