What is radiotherapy? Radiotherapy is one of the three main treatments for tumors. Radiotherapy can be used alone or in combination with surgery and chemotherapy as part of a comprehensive treatment to improve the cure rate of cancer. What is precision radiotherapy? Precision radiotherapy is a form of cancer treatment that combines radiotherapy medicine with computer network technology and physics, and the entire radiotherapy process is computer-controlled. The difference with traditional radiotherapy technology can be summarized as “four most”, i.e. maximum dose in the target area (lesion area), minimum dose to the normal tissues around the target area, most uniform dose distribution in the target area, most accurate target positioning and irradiation, with the advantages of “high precision, high dose, high efficacy and low damage”. “It mainly includes 3D conformal radiotherapy, intensity modulated conformal radiotherapy, image guided radiotherapy, PET/CT localized radiotherapy, etc. Precision radiotherapy is a new tumor radiotherapy technology based on conventional radiotherapy through precise tumor localization, precise plan design, dose calculation and precise execution on the treatment machine, which integrates 3D image processing technology, high-precision dose calculation algorithm, cutting-edge linear gas pedal series technology, advanced tumor diagnosis technology and cutting-edge research results of radiobiology. In the whole process of precision radiotherapy, every step emphasizes precision, which is a qualitative leap compared to conventional radiotherapy.