Evaluation of technetium Tc 99m-labeled biotin for scintigraphic detection of soft tissue inflammation in horses.
OBJECTIVE
To evaluate the use of technetium Tc 99m-labeled EDTA-biotin monomer ((99m)Tc-EB1) as a scintigraphic imaging agent for soft tissue inflammatory lesions in horses.


METHODS
6 healthy adult horses.


METHODS
First (phase 1), the agent's safety and blood-tissue clearance and an appropriate imaging protocol were determined in 6 horses. Each horse was injected with (99m)Tc-EB1 (1.1 GBq, IV, once); images were acquired at intervals during the following 24-hour period. Subsequently (phase 2), inflammation was induced via injection of 200 mg (10 mL) of mepivacaine (0.4 mg/kg) into the right neck musculature and perineurally in the proximal palmar metacarpal region of the right forelimb of 2 horses. Six hours after mepivacaine injection, (99m)Tc-EB1 (2.2 GBq, IV, once) was administered; 8 hours after injection, comparative soft tissue images were acquired after administration of technetium (99m)Tc-hydroxymethylene diphosphonate ((99m)Tc-HDP; 7.4 GBq, IV, once).


RESULTS
After injections of (99m)Tc-EB1, physical examinations, CBCs, and serum biochemical analyses revealed no abnormalities in any horse. Blood clearance of (99m)Tc-EB1 was rapid (A phase, 2.2 minutes; beta phase, 58 minutes). Soft tissue uptake of (99m)Tc-EB1 was immediate and persisted for as long as 4 hours after injection. At 6 hours after IM and perineural mepivacaine injections, mepivacaine-induced inflammation was detectable by use of (99m)Tc-EB1.


CONCLUSIONS
Results indicated that (99m)Tc-EB1 is safe for use in horses and can identify soft tissue inflammation without concurrent uptake in bone. Compared with (99m)Tc-HDP administration, use of (99m)Tc-EB1 extended the duration of soft tissue scintigraphic image acquisition.
Kleine
Lauren G
LG
Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA.
Solano
Mauricio
M
Rusckowski
Mary
M
Hunt
Kathleen E
KE
Johnson
Karen L
KL
Kirker-Head
Carl A
CA
D000818:Animals; D001710:Biotin / Q000031:analogs & derivatives*; D004492:Edetic Acid; D005260:Female; D005552:Forelimb / Q000000981:diagnostic imaging* / Q000473:pathology; D006734:Horse Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D006736:Horses; D007249:Inflammation / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging / Q000662:veterinary; D019275:Radiopharmaceuticals
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C039918:technetium Tc 99m EDTA; D001710:Biotin; D004492:Edetic Acid