Highly differentiated mucoepidermoid carcinoma of the parotid gland can be treated with radiotherapy after surgery. However, the necessity of receiving radiotherapy treatment needs to be judged according to the surgery and postoperative recovery. If the primary lesion is completely removed during the initial surgical resection of highly differentiated mucoepidermoid carcinoma of the parotid gland and the surrounding lymphatic tissues or connective tissues are well cleared to ensure that there are no cancerous cells or tumor tissues left, postoperative radiotherapy is not necessary. Generally speaking, if the initial surgery achieves a radical effect and reduces the chance of recurrence or metastasis after surgery, no radiotherapy can be considered. However, if localized cancer cells are still found after initial surgery or if there is a possibility of recurrence or metastasis in the surrounding tissues, postoperative radiotherapy is recommended, which can effectively inhibit the proliferation of cancer cells, consolidate the effect of surgical treatment, and at the same time help to reduce the chances of metastasis or recurrence after surgery. Whether highly differentiated mucoepidermoid carcinoma of parotid gland or other malignant tumors need radiotherapy after surgery should be carefully chosen on the advice of doctor, and should not be carried out without authorization.