In vivo SPECT imaging of CNS D-2 dopamine receptors: initial studies with iodine-123-IBZM in humans.
Iodobenzamide (IBZM) is a D-2 dopamine receptor antagonist. In this paper the results of Phase I clinical studies of iodine-123-(123I)IBZM in humans are reported. Preliminary imaging studies, both planar and single-photon emission tomography (SPECT), of no-carrier added [123I]IBZM in humans show specific localization in the basal ganglia of the brain. At 2 hr after an i.v. injection, the brain uptake was 3.72% of the dose, and at 20 hr later the uptake diminished to 0.7%. Radiation dosimetry calculation indicated that the radiation dose to the brain was minimum, 0.039 rad/mCi, while the large intestine wall received the highest dose, 0.28 mrad/mCi. The radiation dosimetry and pharmacology data suggest that this agent is safe for human use.
Kung
H F
HF
Department of Radiology, University of Pennsylvania, Philadelphia.
Alavi
A
A
Chang
W
W
Kung
M P
MP
Keyes
J W
JW
Velchik
M G
MG
Billings
J
J
Pan
S
S
Noto
R
R
Rausch
D000328:Adult; D001479:Basal Ganglia / Q000000981:diagnostic imaging / Q000378:metabolism; D001549:Benzamides / Q000008:administration & dosage / Q000493:pharmacokinetics; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D004341:Drug Evaluation; D006801:Humans; D007275:Injections, Intravenous; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011759:Pyrrolidines / Q000008:administration & dosage / Q000493:pharmacokinetics; D011954:Receptors, Dopamine / Q000032:analysis*; D017448:Receptors, Dopamine D2; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon
D001549:Benzamides; D007457:Iodine Radioisotopes; D011759:Pyrrolidines; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide