IMRT is an advanced form of three-dimensional conformal radiotherapy. It is generally used to provide individualized irradiation of target areas that are not in a uniform structure and maximum protection of the surrounding normal tissues. With IMRT planning that uses advanced treatment planning algorithms, angle of doses appropriate to the shape of the target can be achieved with steep dose reduction outside the target. In this way, while the maximum dose can be given to the target compared to conformal treatments, it is ensured that the healthy tissues in the environment receive the least dose. Because of these properties, it is frequently used in head and neck tumors and tumors located in the pelvic region.