Author: Kanematsu, N.
Paper Title Page
THPS073 Dosimetric Impact of Multiple Energy Operation in Carbon-ion Radiotherapy 3598
 
  • T. Inaniwa, T. Furukawa, N. Kanematsu, S. Mori, K. Noda, S. Sato, T. Shirai
    NIRS, Chiba-shi, Japan
 
  In radiotherapy with a scanned carbon beam, its Bragg peak is placed within the target volume either by inserting the range shifter plates or by changing the beam energy extracted from the synchrotron. The former method (range shifter scanning: RS) is adopted in NIRS while the latter method (active energy scanning: ES) has been used in GSI and HIT. In NIRS, an intermediate method, a combination scanning (CS), is now under consideration where eleven beam energies having the ranges with 30 mm intervals are prepared and used in conjunction with the range shifter plates for slighter range shift. The disadvantages of the RS are the beam spread due to the multiple scattering within the range shifter plates and the production of fragment particles through the nuclear reactions within them. On the other hand, for the ES, severely time-consuming beam commissioning and the expensive devices are required. In this study, we compare these three methods from the viewpoint of dose distributions and the impacts for clinical cases will be discussed.