Study on the system for evaluating the irradiation field by using positron emitters produced through fragmentation reactions

The purpose of this study was to evaluate the field irradiated with incident ions and the deposited dose distribution in a patient body, we have proposed to use the positron emitters produced through projectile fragmentation reactions of stable heavy ions. Through the previous works, we have established the method to estimate the range of incident ions and the one dimensional (1D) dose distributions in homogeneous and bi-material targets by using the Maximum Likelihood Estimation (MLE) method. In this year, we performed 3D cube shape irradiation experiment to a uniform PMMA target. By extending the method to 3D, we estimated the proximal and the distal edge of the 3D dose distribution in the target with an accuracy of 4.0 and 0.5 mm for each edge. The range estimation in multi-layer targets was also investigated. (author)