Intensity modulated radiation therapy, or IMRT, is a specialized form of 3D-CRT that allows radiation to be more exactly shaped to fit the tumor. With IMRT, the radiation beam can be broken up into many "beamlets," and the intensity of each beamlet can be adjusted individually. Using IMRT, it may be possible to further limit the amount of radiation received by healthy tissue near the tumor.
In some situations, this may also safely allow a higher dose of radiation to be delivered to the tumor, potentially increasing the chance of a cure.
This highly complex and promising technique was started at Dharamshila Narayana Superspeciality Hospital in 2005. Now, IMRT is being delivered through VMAT techniques in a continuous arc around patient effectively, from infinite delivery angles; reducing the integral dose to one tenth and treatment time to few minutes.
IMRT is used for tumours arising from Head and Neck, Brain, Lungs, Lymphomas and Gyneccological Cancers.