To reach the tumour, the radiation needs to pass through healthy tissues. So as not to damage these healthy tissues, the dose of radiation is administered using a large number of beams. The dose administered by each is extremely small, while the dose received by the tumour, where all the beams are concentrated, is high. IMRT divides each beam into multiple segments, so the dose administered by each is not uniform, but is adapted, or modulated to the thickness of the tissue through which it must pass to reach the tumour. The main objective is to spare normal healthy tissue while administering the maximum dose to the tumour, to prevent sequelae from the treatment. The aim is to cure more and damage less.