One of the most important steps related with planning systems and the success in IMRT is the Optimization Process. The mean goal is arrive at an optimal intensity pattern through objective functions taking into account the absorbed dose constraints. Moreover, VMAT may ensure high dose conformity and sparing of normal tissue reducing the number of MU and the delivery times respect to other established IMRT techniques such as step and shoot, and dMLC. Head and neck carcinomas have moved from 3D-CRT to IMRT radiotherapy, having a great benefit of sparing OARs with reduction of the treatment time especially in treatment plans with high complexity. Inverse planning techniques have helped to ensure a high PTV conformation during the treatment in breast cancer. Inverse techniques have provided a better plan quality for prostate case and for Lung PTV coverage has been successfully completed by the dMLC plan. In this work, it was measured the interrelation between differences and advantages with each described technique mentioned.
