Inter-tissue radiotherapy with nuclear 125 iodine particles has high local control rate and low adverse effects, especially for adenoid tumors, and it should be the first method for adenoid cystic carcinoma. For highly differentiated squamous cell carcinoma, the efficacy is better than that of ordinary external irradiation, while for poorly differentiated squamous cell carcinoma, the efficacy is relatively poor. The close proximity to the oral mucosa and skin can cause mouth ulcers and skin darkening, sometimes with a burning sensation or even pain. It is similar to a kind of post-mounted therapy machine treatment, i.e. ultra-short distance radiotherapy, which is a local radiotherapy with high radiation dose because of its accurate positioning and low damage to normal tissues. No matter what kind of radiotherapy, it can not cure most of oral squamous cell carcinoma. If these carcinomas are not sensitive to radiotherapy and can still be operated, it is necessary to discontinue radiotherapy in time to leave a chance for surgery; otherwise, continuous high-dose radiotherapy can not control the development of lesions, and radioactive jaw necrosis will occur, causing postoperative trauma not to heal and bringing difficulties to local repair.