Application of Optimization with Scaled Conjugate Gradient Algorithm in IMRT

Objective To implement the optimization of beam weight in IMRT planning optimization. Methods The treatment planning system of IMRT has been developed with SCG algorithm for determining the intensity-modulated beams and pencil beam model for dose distribution. Results A example of a lung case has been optimized by the IMRT system. The DVH shows that 97%PTV is irradiated by 95%~105% of the described dose. OAR and normal tissue are irradiated by no more than 15% and 40% respectively. Conclusion SCG algorithm implemented as an inverse planning algorithm for determining the intensity-modulated beams that will most closely generate a desired dose distribution is presented as well as a method for dose calculation in IMRT using pencil beam model.