The role of radiotherapy in the treatment of pancreatic cancer is becoming more and more important. The effects of radiotherapy are: 1. The tumor is relatively huge, but it is also relatively limited and there is no distant metastasis, such patients can first shrink the local tumor through radiotherapy, and then create opportunities for the surgeon to make the surgery easier and more convenient. The surgical resection will be more complete; 2. There are also some patients who have already undergone surgical treatment beforehand, but the pancreatic cancer is locally advanced, the tumor is relatively large, there are lymph node metastases, or there are local malignant factors such as cholangiocarcinoma emboli. After surgery, radiotherapy can be added to the tumor bed area to kill the microscopic tumor foci that may remain; 3.