The radiation dose of 51.6GyE in 12 fractions is currently widely used in Japan, and clinical studies of 51.6GyE/12Fx have also been carried out for SBRT. There are some differences in equipment and carbon ion treatment planning system used between Japan and our center. Therefore, we designed this phase I clinical study to explore the optimal dose of 12 fractions of carbon ion radiotherapy for prostate cancer.
