Perspective of MRI-Guided Radiotherapy in Japan

Abstract

Since 2012, Tohoku University Hospital has been preparing for MR image-guided radiotherapy. Although it was much later than expected, from February 28th, 2022, the MR Linac (Elekta Unity) started using clinically as the second institution in Japan. By integrating MRI and Linac, it is possible to (1) visualize soft tissue clearly, enable accurate positioning, and design a treatment plan that matches the condition of the day on the spot, and (2) visualize in real-time during radiation irradiation, it enables to perform highly accurate irradiation against the movement of the tumor due to respiration. However, there are major problems such as re-setting of ROI, creation of dose distribution, approval, verification, etc., which require a lot of time and manpower. Therefore, the number of irradiation patients per day is limited. Unfortunately, there is no addition of medical fees, which can be said to be a major issue in the future.