The patients are older, and most of them are diagnosed with advanced gastric cancer. The general route of metastasis is lymph node metastasis. In order to exclude other organ metastasis, it is feasible for PETCT to know the condition. I think the patient should have used postoperative analgesic drugs such as analgesic pump, which I think caused some involuntary behavior of the patient. If the patient is not in great pain, consider suspending the application of analgesic pump until the drug metabolism is completed. This process takes about 3 days and occasionally lasts for a long time.