Development of TREATMENT PLANNING SOFTWARE FOR CARBON-ION SCANNING AT HIMAC

In order to use an intensity-controlled raster scan method at the new treatment facility in HIMAC, we have developed a code system dedicated to the planning of radiotherapy with the scanned 12C beam. Inverse planning techniques are implemented in the software in order to obtain the uniform biological dose distribution within the planned target volume (PTV) as well as reduce the dose delivered to the organ at risks (OARs) delineated on clinical CT images. The scan trajectory is determined so that the path length will be minimized by applying a fast simulated annealing algorithm for scan trajectory optimisation. Furthermore, the extra dose inevitably delivered to the irradiated site during the beam transition time from one spot to the next spot is integrated into the inverse planning process to shorten the treatment time. The code also copes with the planning for intensity modulated ion therapy (IMIT). The reliability of the developed code has been confirmed through the irradiation experiments at the secondary beam line in HIMAC.11th International Conference on Heavy Ion Accelerator Technolog