Conclusion
(64)Cu-ATSM appears to be a safe radiopharmaceutical that can be used to obtain high-quality images of tumor hypoxia in human cancers.
Methods
The preclinical toxicology and pharmacology of a copper-ATSM formulation was examined using standard in vitro and in vivo assays, as well as 14-d toxicity studies in both rats and rabbits. For the clinical test-retest imaging study, 10 patients with cervical carcinoma underwent PET on separate days with (60)Cu-ATSM and (64)Cu-ATSM. Image quality was assessed qualitatively, and the tumor-to-muscle activity ratio was measured for each tracer.
Results
The toxicology and pharmacology data demonstrated that the formulation has an appropriate margin of safety for clinical use. In the patient study, we found that the image quality with (64)Cu-ATSM was better than that with (60)Cu-ATSM because of lower noise. In addition, we found that the pattern and magnitude of tumor uptake of (60)Cu-ATSM and (64)Cu-ATSM on studies separated by 1-9 d were similar.