Figure 1. Dose distribution of CIRT. A case of local recurrence of rectal cancer. (A) Tumor extension defined in T2 weighted MRI scan. (B, C). Planning CT scan with typical steep gradient of dose distribution of carbon ion radiotherapy; red area represents the prescription dose of 60 GyRBE, while the light blue area over the edge of the tumour represents the dose of 30 GyRBE.
