Is extensive abutment of the duodenum without invasion a contraindication to SBRT for pancreatic tumors?

First, let's be clear that we are talking about a palliative (or neoadjuvant) dose of radiation (53Gy BED). A similar dose, 54Gy in 30 fx, failed to improved overall survival in a randomized phase III trial (LAP07). Next, let's consider one of the most fundamental principles in radiotherapy, fractio...