Clinically, radiotherapy is usually used in fractionated radiotherapy, and the general conventional segmentation scheme is 1-5 consecutive radiotherapy sessions per week once a day, with Saturday and Sunday off. The total course of treatment takes different time according to the purpose of radiotherapy. If the tumor cannot be removed surgically, radiotherapy as the main treatment usually takes more than 6 weeks, if the tumor is removed surgically, radiotherapy is to reduce recurrence, as adjuvant radiotherapy usually takes about 5 weeks. There are also many modes of radiotherapy, such as hyper-segmentation radiotherapy, continuous gas pedal hyper-segmentation radiotherapy, etc. The total course of treatment will be shortened by increasing the number of radiotherapy sessions per day. Now there are also new radiotherapy modalities such as stereotactic radiotherapy. The dose of single radiotherapy is very high, and the total course of treatment will be shortened accordingly, but the effective biological dose remains the same or even higher. The time required for each radiotherapy session is related to the dose given, and the higher the dose the longer the time required for the same dose rate. Conventional split doses are currently usually a few minutes per session.