Intensity-modulated radiation therapy (IMRT) is an advanced type of radiation therapy that is used to treat cancer and benign tumours. Beams of radiation are controlled to follow to the shape of the tumour and to have different intensities to treat the tumour accurately. The radiation intensity of each beam is controlled, and the beam shape changes throughout each treatment according to the tumour.
The aim of IMRT is to reduce the amount of radiation to the healthy tissues and limit the side effects of the treatment.