RESUMO
The methylguanidine derivative 11C-GMOM (11C-labeled N-(2-chloro-3-thiomethylphenyl)-N'-(3-methoxyphenyl)-N'-methylguanidine) has been used successfully to quantify N-methyl-d-aspartate (NMDA) receptor binding in humans. The purpose of the present study was to estimate the 11C-GMOM radiation dose in healthy humans. Methods: After 11C-GMOM injection, 3 female and 2 male subjects underwent 10 consecutive whole-body PET scans in approximately 77 min. Seven source organs were defined manually, scaled to a sex-specific reference, and residence times were calculated for input into OLINDA/EXM software. Accepted tissue-weighting factors were used to calculate the effective dose. Results: The mean absorbed radiation doses in source organs ranged from 7.7 µGy·MBq-1 in the brain to 12.7 µGy·MBq-1 in the spleen. The effective dose (±SD) was 4.5 ± 0.5 µSv·MBq-1Conclusion: The effective dose of 11C-GMOM is at the lower end of the range seen for other 11C-labeled ligands, allowing for serial PET scanning in a single subject.