I am glad you are doing well after surgery. In general, every patient is different, and each tumor has its own biology that requires individualized treatment. I usually recommend to my patients with tumors in the pancreas, bile duct, or ampulla that surgery alone is not curative; treatment usually requires a combination of surgery (to remove the tumor where it is and sample lymph nodes) and chemotherapy to prevent the tumor from coming back. Patients with the best survival are mainly those treated with both chemotherapy and surgery. While I cannot speak to the exact reason that radiation was recommended after your operation, we tend to reserve these for patients with tumor that has been left behind (a positive margin). However, this also requires an individualized discussion with a radiation oncologist. If there is any uncertainty about the plan, I never hesitate to have a patient get a second opinion (whether it is about surgery, chemotherapy, or radiation).