[Proposal of Criteria for Release of Patients and Use of the Normal Ward in 64Cu-ATSM Internal Radiotherapy].

Abstract

Cu-ATSM [Cu-diacetyl-bis(N4-methylthiosemicarbazone)] is a small molecule chelate of radioactive Cu with ATSM ligand, and has been developed as a radiopharmaceutical for positron-emission tomography (PET) imaging to detect hypoxic regions in tumors. Among the radioactive Cu, 64Cu has a unique feature that it emits not only positron for PET imaging, but also β- particles and Auger electrons that can damage tumor cells. Therefore, 64Cu-ATSM can be developed as an internal radiotherapy agent against tumors. Particularly for malignant brain tumors, a clinical PET study has reported that Cu-ATSM shows high tumor accumulation; and a non-clinical study has demonstrated that 64Cu-ATSM treatment shows high anti-tumor effects. Based on these findings, clinical development for 64Cu-ATSM internal radiotherapy is expected. Therefore, this paper is prepared to propose the timing to release a patient administered 64Cu-ATSM from dedicated internal radiotherapy rooms to protect the general public and carers from the radiation. The special consideration for the radiation protection is also proposed to treat patients in the normal ward after the administration of 64Cu-ATSM.