Rational evaluation of the therapeutic effect and dosimetry of auger electrons for radionuclide therapy in a cell culture model

Shinohara, Ayaka*; Hanaoka, Hirofumi*; Sakashita, Tetsuya*; Sato, Tatsuhiko   ; Yamaguchi, Aiko*; Ishioka, Noriko*; Tsushima, Yoshito*

Radionuclide therapy with low-energy auger electron emitters could potentially provide high anti-tumor efficacy while keeping normal organs toxicity low. In this study, we evaluated the usefulness of auger electron emitter I and compared it with beta-emitter I for tumor treatment in 2D and 3D cell culture models. The computer simulation model for 2D and 3D cell culture were constructed, and the absorbed radiation dose of I or I in each model were calculated by using a Monte Carlo simulation code (PHITS). The therapeutic effect of I was comparable to that of I in 2D model, but the efficacy was inferior to that of I-MIBG in 3D model, since crossfire effect is negligible and the homogeneous distribution of radionuclide was insufficient.