Divesh Kumar

Publications (2)2.25 Total impact

• Article: Is (99m)Tc-labelled pamidronate a better agent than (99m)Tc-medronate for bone imaging?

  Vijay Kumar, Divesh Kumar, Robert B Howman-Giles, David G Little
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  ABSTRACT: To evaluate the potential of (99m)Tc-pamidronate ((99m)Tc-APD) against (99m)Tc-medronate ((99m)Tc-MDP) as a new bone-seeking agent using intact bone and fractured femur in a rat model. (99m)Tc-APD was prepared by the stannous reduction method. Scintigraphic images were obtained at 2 h and 24 h after intravenous injection of (99m)Tc-APD or (99m)Tc-MDP in rats, then they were culled to estimate activities in various organs. Bone uptake (as percent injected dose/gram weight) was estimated in an intact femur and in 1 week post-fracture model. The urinary excretion dose (as percent injected dose) was also estimated. The bone uptake of (99m)Tc-APD was significantly higher (P<0.05) than (99m)Tc-MDP at 2 h and 24 h post-injection studies. (99m)Tc-APD uptake was further increased (P<0.05) in the fracture model than the intact femur. (99m)Tc-APD uptake in the soft tissues including liver and the kidneys was lower than (99m)Tc-MDP. Renal excretion was faster and the ratios of bone to blood and bone to soft tissues were higher with APD than MDP. APD dose was selected at 1% of MDP, to obviate therapeutic effect, as the former compound is 100 times more potent than MDP. Our results suggest that (99m)Tc-APD uptake by intact bone and fractured bone was significantly higher than (99m)Tc-MDP. The renal clearance of (99m)Tc-APD was faster and soft tissue uptake was lower than (99m)Tc-MDP. These results suggest that APD has the potential to become an excellent bone-imaging agent.
  Nuclear Medicine Communications 03/2007; 28(2):101-7. · 1.40 Impact Factor
• Article: Evaluation of biodistribution by local versus systemic administration of 99mTc-labeled pamidronate.

  Divesh Kumar, Vijay Kumar, David G Little, Robert B Howman-Giles, Effie Wong, Sinan O Ali
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  ABSTRACT: There is an emerging interest in utilizing local and systemic administration of bisphosphonates in orthopedics. The primary objective of this study was to use (99m)Tc-pamidronate ((99m)Tc-PAM) as a tool and compare bone and tissue uptake by local versus systemic administration. (99m)Tc-PAM was administered intravenously (i.v.), subcutaneously (s.c.) and by direct application (d.a.) on a surgically exposed and fractured femur (d.a.#f). The animals were imaged at 2 h and 24 h after administration and then killed. Organs were harvested, and their radioactivity was estimated. Specific uptake in the right femur was compared between groups, as was systemic exposure to (99m)Tc PAM. Bone uptake of (99m)Tc-PAM in the i.v. and s.c. groups was 2.2 +/- 0.15 and 0.65 +/- 0.07% ID/g, respectively, at the 2 h time point. Uptake by surgically exposed right femur (d.a) was 5.15 +/- 0.26% ID/g, 134% higher than the femoral uptake by the i.v. method (P < 0.05). In the presence of exposed bone when the femur was fractured (d.a.#f), the uptake was 7.89 +/- 0.46% ID/g, a further 50% increase (P < 0.05). The uptake of (99m)Tc-PAM increased after 24 h of application to 2.4 +/- 0.15, 1.53 +/- 0.09, 7.94 +/- 0.99, and 13.2 +/- 0.80% ID/g) for i.v., s.c., d.a., and d.a.#f methods, respectively. The increases in uptake for the d.a. methods were significantly higher than for the local methods at the 24-h time point (P < 0.05). Although renal uptake was comparable with the i.v. and s.c. methods (0.22 +/- 0.03 and 0.22 +/- 0.04% ID/g), it was significantly lower with the d.a. methods (0.05 +/- 0.07 and 0.16 +/- 0.07% ID/g) (P < 0.05). The corresponding urinary excretion was 55%, 45%, 36%, and 35% of the injected dose at 24 h. The results indicate that the bone uptake of (99m)Tc-PAM was significantly higher (P = 0.001) and the kidney uptake significantly lower (P = 0.004) with the d.a. methods than with the i.v. or s.c. method. The findings indicate the need for further study into the potential of local administration of bisphosphonates in the presence of orthopedic indications.
  Journal of Orthopaedic Science 10/2006; 11(5):512-20. · 0.84 Impact Factor