Background: Surgical therapy remains the only curative modality for pancreatic cancer, though survival remains quite poor even for patients with resected early stage disease. Better (neo) adjuvant therapies are needed to improve resectability rates for patients with borderline resectable pancreatic cancer and to prevent recurrence following resection. We undertook this pilot study to determine the safety of accelerated fraction radiotherapy (AFRT) with capecitabine in such patients. Methods: Eligible patients have histologically confirmed borderline resectable adenocarcinoma of the pancreas as defined by the MD Anderson categories of vascular involvement, indeterminate metastatic disease, borderline performance status; normal organ function; and no prior therapy for pancreatic cancer. Radiation is given as external beam radiation therapy to a dose of 50 Gy delivered in 20, 2.5 Gy fractions Mon-Fri using IMRT. If insurance denied IMRT, 3D conformal techniques with daily image guidance is permitted. Capecitabine is delivered as 825mg/m² BID on radiation days. The primary outcome is to determine the frequency of treatment-related adverse events (AE). Planned enrollment is 40 pts. Results: 10 pts have enrolled to date. 8/10 received IMRT. This regimen has been exceedingly tolerable. Lymphopenia is the most common AE (n=10), grade 3-4 n=6. Other common toxicities were hyponatremia (n=6), fatigue (n=5). Grade 3 AE occurred in 8 pts, grade 4 in 3 patients. One pt had hemorrhage from a radiation induced gastric ulcer complicated by an MI. 5/10 pts had stable disease and were resected and 4/5 had an R0 resection. In the remaining 5/10 patients, disease progressed outside the pancreas and they are receiving palliative therapy. Conclusions: The combination of AFRT and capecitabine was well tolerated. Xenograft models derived from these patients’ tumors are being used to study molecular mechanisms of treatment resistance that could be targeted in a follow up phase II study building on this platform.