title: Radioimaging of implants in rats using Tc-99m-MDP.
abstract: Radiopharmaceutical isotopes are widely used clinically to detect tumors of osteogenic origin. One example is Technetium-99m methylene diphosphonate (Tc-99m-MDP). When viewed with a gamma camera, the concentration of the isotope (increased gamma activity) indicates an area of increased bone activity. This technology provides an opportunity to measure bone growth around implants in vivo. The purpose of this study was to measure Tc-99m-MDP activity around titanium alloy implants placed in the tibiae of rats. Some implant sites were treated with a growth factor; other sites served as controls. The hypothesis tested was that implants placed with a growth factor would have greater associated Tc-99m-MDP activity. Twelve adult male Sprague-Dawley rats were anesthetized and surgical access to the medial proximal tibiae was obtained. Titanium alloy screw implants were placed in six animals along with 65 microgram of acidic fibroblast growth factor (FGF-1); the other six animals received implants only and served as controls. After five days, rats were injected with 1500 microCi of Tc-99m-MDP. After 3 hours, rats were imaged with a gamma camera. The Tc-99m-MDP intensity associated with each implant was quantified and the means for each group were compared using ANOVA. Implants treated with FGF-1 demonstrated significantly more Tc-99m-MDP activity than implants alone. This suggests that Tc-99m-MDP analysis may be a useful tool for determining bone growth around implants in laboratory animals in vivo.
authors.affiliation: Department of Biomaterials, University of Alabama School of Dentistry, 1530 3rd Avenue South, Birmingham, AL 35294-0007, USA. mikemc@uab.edu
authors.forename: M
authors.initials: M
authors.lastname: McCracken
authors.forename: K
authors.initials: K
authors.lastname: Zinn
authors.forename: J E
authors.initials: JE
authors.lastname: Lemons
authors.forename: J A
authors.initials: JA
authors.lastname: Thompson
authors.forename: D
authors.initials: D
authors.lastname: Feldman
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects* / Q000502:physiology; D016220:Fibroblast Growth Factor 1 / Q000494:pharmacology*; D020007:Implants, Experimental; D008297:Male; D011877:Radionuclide Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D013669:Technetium Tc 99m Medronate; D013977:Tibia / Q000000981:diagnostic imaging; D014025:Titanium
chemical_list: D016220:Fibroblast Growth Factor 1; D014025:Titanium; D013669:Technetium Tc 99m Medronate