Radiation therapy is still one of the main methods of pancreatic cancer treatment. In the past, external irradiation was mainly used. External irradiation is the application of external radiation source to reach the tumor through the normal tissues of human body, because the pancreas is located in the deep posterior peritoneum of the upper abdomen and there are tissues such as stomach, colon, bile duct and liver in front of it, and these tissues are more sensitive to radiation and less tolerable, and the irradiation treatment of pancreatic cancer requires avoiding these organs as much as possible, which can reduce nausea, vomiting or abnormal liver function caused during radiotherapy. This can reduce the adverse effects such as nausea, vomiting or abnormal liver function during radiotherapy. Even so, it is very likely to cause bleeding, perforation or stricture of the stomach and intestines. To achieve the radiation dose of tumor treatment, radioactive particles are placed directly into the tumor, and the tumor receives high dose of radiotherapy through the low-energy γ-rays emitted from the local radiation source, which can not only achieve more ideal treatment effect, but also reduce the radiation damage to the surrounding normal tissues. The main methods of radioactive particle implantation include: ① Percutaneous puncture implantation. ② Intraoperative implantation.