10 C.F.R. § 35.604
Surveys of patients and human research subjects treated with a remote afterloader unit
(a) Before releasing a patient or a human research subject from licensee control, a licensee shall survey the patient or the human research subject and the remote afterloader unit with a portable radiation detection survey instrument to confirm that the source(s) has been removed from the patient or human research subject and returned to the safe shielded position.
(b) A licensee shall retain a record of these surveys in accordance with § 35.2404.