An optimization study for targeted alpha therapy: Ion behaviours and dose calculations within ICRU-compact bone tissue

Abstract

Targeted Alpha Therapy is a therapy method that can be applied to late-stage cancers, including bone metastases, and it is a hope for millions of people. This study is an optimization that includes the interactions of bone tissue with characteristic alpha particles of 223Ra, 225Ac (together with their decay product), which are frequently preferred in Targeted Alpha Therapy that aim to destroy metastatic tumour tissue in bone tissue. This optimization is designed to analyse some events such as ion spacing of alpha particles that can only infiltrate into bone tissue, stopping power of the target, dose calculations and atomic displacement. To ensure accuracy, calculations such as mass stopping power and ionizing dose obtained from CASP, SRIM and ASTAR programs were also compared among themselves. And then, tissue doses were calculated in IDAC-Dose 2.1, taking into account the half-lives of the radioisotopes, the administered activity and the integration time. Alpha particles of 213Po had the highest ion spacing, while alpha particles of 223Ra had the lowest ion range.