How do you decide timing of adjuvant radiation with respect to chemotherapy for a patient with resected pancreatic adenocarcinoma with microscopic positive margins?

Level 1 evidence supports chemotherapy, FOLFIRINOX is the standard. The benefit of radiation is modest in comparison and based on post-hoc analysis of phase III trials (ESPAC-1, and others that are themselves nearly uninterpretable). The answer to this question is chemotherapy followed by restaging and consideration of chemoradiation for a positive margin. If there is no DM after chemotherapy, proceed with chemoradiation. The dose should reliably control + margins (45Gy in 5 weeks to the regional nodes and tumor bed and 62.5Gy SIB to the + margin and with IMRT is what we use).