[Measurement of Airborne Radioactivity in the Inpatient Room after Administering [⁶⁴Cu]Cu-ATSM to Patients]

[⁶⁴Cu]Cu-ATSM is a radiotherapeutics under clinical trials. It is necessary to take appropriate measures to limit its exposure and ensures its airborne concentrations do not exceed legally permitted levels. Therefore, the purpose of this study was to measure the airborne radioactivity concentration in the inpatient room after administering [⁶⁴Cu]Cu-ATSM to patients.

Three patients with malignant glioma were intravenously administered [⁶⁴Cu]Cu-ATSM (100 MBq/kg ± 10%) in an inpatient room, and the airborne radioactivity concentrations were measured at two locations in the room (in the center of the room and near the entrance of the room) using a filter collection method.

After administration of [⁶⁴Cu]Cu-ATSM, the airborne radioactivity concentrations measured were around or below the limit of detection (8.24×10^-7 Bq/cm³ or lower) in all three patients, and all concentrations were consistently below 1/10,000 of the legal airborne concentration limit of ⁶⁴Cu (1×10^-1 Bq/cm³).

The results of this study confirmed that the airborne concentration of [⁶⁴Cu]Cu-ATSM after administration to patients was below the legally permitted level.