Ann: First patient treated in theranostic prostate cancer trial, page-15

People have nuclear scans every day and will excrete some radioisotope, usually in urine, which is not a hazard at diagnostic doses.
The potential benefit of the longer half life of Cu-64 for diagnostic imaging becomes apparent when you combine it with Cu-67 as a therapeutic pair. By acquiring multiple time points of imaging, one can calculate organ and tumour dosimetry so that the therapy dose of Cu-67 administered can be determined for the individual patient. This is personalised medicine, with accurate dosing, which none of the currently available Theranostics agents are able to do. The current paradigm of Ga-68 or F-18 PET PSMA imaging paired with a Lu-177 labelled peptide is not a true Theranostics pair (unlike Cu-64/Cu-67) and radiation dose prescription is largely empirical.