Pharmacokinetic studies and human absorbed dose estimation of 68Ga-(4 {[(bis (phosphonomethyl)) carbamoyl] methyl}-7,10-bis(carboxymethy l) -1,4,7,10-tetraazacyclododec-1-yl) acetic acid

Background: in this study, human absorbed dose of a newly introduced boneimaging agent, ^68ga-(4-{[(bis(phosphonomethyl))carbamoyl]methyl}-7,10-bis(carboxymethyl)-1,4,7,10-tetraazacyclododec-1-yl) acetic acid (68ga-bpamd), wasestimated based on the rats data. materials and methods: ^68ga was obtainedfrom the ^68ge/^68ga generator and it's radionuclidic and radiochemical puritieswere investigated. ^68ga-bpamd complex was prepared at optimal conditionsand the radiochemical purity was studied using instant thin layerchromatography (itlc) method. the final preparation was injected to thenormal rats and the biodistribution of the complex was followed up to 120min post injection. the accumulated activity for animal organs was calculated.finally, the human absorbed dose of the complexes was estimated by radarmethod. results: 68ga-bpamd complex was prepared in high radiochemicalpurity (>99%, itlc) at optimal conditions. the biodistribution of the complexdemonstrated that the main remained radioactivity would considerablyaccumulate into the bones. the results showed the highest amounts ofabsorbed dose on the bone surface (0.253 mgy/mbq) and in the bonemarrow (0.250 mgy/mbq), while the other organs would receive aninsignificant absorbed dose after injection of the ^68ga-bpamd complex.conclusion: the comparison of dosimetric results for 68ga-bpamd with othercomplexes shows this complex is a safer agent for bone scanning. thisproperty as well as other characteristics such as the high resolution images ofthe positron emission tomography (pet) scanning and the availability of ^68gain the form of ^68ge/68ga generator, make this complex as a suitable agent forpet bone imaging.