Can the {sup 72}Se/{sup 72}As PET generator go to the clinic?

Arsenic-72 (half-life 1.1 days) is a radioisotope with significant potential to support imaging by positron emission tomography (PET). Its physical decay characteristics and the versatile chemistry of arsenic make this nuclide very attractive for the synthesis of a variety of PET radiopharmaceuticals, particularly in the area of oncology. Since {sup 72}As is the daughter of the longer lived {sup 72}Se (half-life 8.5 days), a radiochemical generator could be used on-site at a clinical imaging center or regional radiopharmacy to provide the {sup 72}As radiopharmaceuticals in high specific activity. A generator system based on precipitation of elemental selenium followed by filtration to yield the arsenic-containing labeling solution has been developed. The applicability of {sup 72}As for PET imaging in comparison to {sup 18}F has been demonstrated. Due to these developments, there is growing interest in a clinical generator system to provide {sup 72}As for PET.