Technetium-99m diethyldithiocarbamate (DDC): comparison with thallium-201 DDC as an agent for brain imaging.
Technetium-99m diethyldithiocarbamate (99mTc-DDC) was prepared by reduction of [99mTc]pertechnetate with formamidine sulfinic acid in the presence of DDC at alkaline pH, both from extemporaneous solutions and in a kit formulation. The properties of 99mTc-DDC were compared in vitro and in vivo with those of 201Tl-DDC, an agent used for cerebral perfusion imaging (CPI). 99mTc-DDC is a lipophilic complex but its oil/water partition coefficient is lower than that of 201Tl-DDC. 99mTc-DDC also shows greater binding to plasma proteins. Studies in rabbits show that 99mTc-DDC enters the brain but is not retained to the same extent as 201Tl-DDC. This lack of retention may be because 99mTc-DDC does not decompose rapidly in lipid media as 201Tl-DDC does. These results suggest that 99mTc-DDC in its present formulation is not suitable for CPI with SPECT.
Ballinger
J R
JR
Division of Nuclear Medicine, Ottawa Civic Hospital, Canada.
Gerson
B
B
Gulenchyn
K Y
KY
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging*; D004050:Ditiocarb; D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; D011817:Rabbits; D011933:Reagent Kits, Diagnostic; D013667:Technetium; D013794:Thallium Radioisotopes; D014055:Tomography, Emission-Computed / Q000379:methods
D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; D011933:Reagent Kits, Diagnostic; D013794:Thallium Radioisotopes; C034630:technetium Tc 99m diethyldithiocarbamate; D013667:Technetium; D004050:Ditiocarb