Intensity Modulated Radiation Therapy IMRT - Intensity-modulated radiation therapy is an advanced mode of high-precision radiotherapy which uses computer-controlled linear accelerators in order to deliver the precise radiation doses to an infectious tumor or just particular areas within the tumor. This therapy also allows for the radiation dose to observe more precisely to the 3D shape of the tumor by controlling or modulating the intensity of the beam in several small volumes. Intensity Modulated Radiation Therapy also allows higher radiation doses to be focused to the regions within a patient’s tumor while minimizing the dose to the normal critical structures around. IMRT is carefully planned by using 3D CT or MRI images of the patient in the conjunction with the calculations that are computerized dose to find the dose intensity pattern which will best conform the tumor shape. The combinations of multiple intensity-modulated fields from various beam directions will produce a custom tailored radiation dose which maximizes the tumor dose while minimizing the dose to adjacent normal tissues. IMRT has the potential to reduce the treatment toxicity, even when doses aren’t increased. Because of its complexity, IMRT requires a slightly longer daily treatment times as well as an additional planning and safety checks prior the patient can start treatment. At present this therapy is being used most extensively in order to treat head and neck, prostate, and central nervous system cancers. It has also been used in limited situations for treating thyroid, lung, breast, as well as in gynecologic malignancies, gastrointestinal, and certain types of sarcomas. Intensity Modulated Radiation Therapy may also be beneficial to treat pediatric malignancies.