[Three-Dimensional Dosimetry of Carbon Ion Beams by Gel Dosimeters].

A three-dimensional dosimetry method is strongly required in the dose distribution measurement of a patient QA of a heavy ion therapy. Nanocomposite Fricke gel dosimeters are the most possible candidate for this purpose. Experimental dose distribution measurements were carried out using a scanning irradiation port of Gunma University Heavy Ion Medical Center. The result showed no significant LET dependence and indicated a possibility for a precise dosimetry of a heavy ion therapy. It also indicated the importance of three-dimensional dosimetry in the commissioning process of the treatment accelerator.