Evaluation of biodistribution by local versus systemic administration of 99mTc-labeled pamidronate |
| |
Authors: | Divesh Kumar Vijay Kumar David G Little Robert B Howman-Giles Effie Wong Sinan O Ali |
| |
Institution: | (1) Department of Nuclear Medicine, University of Macquarie, Department of Biological Science, The Children's Hospital at Westmead and the Westmead Hospital, Westmead, Australia;(2) Department of Nuclear Medicine, University of Sydney, Disciple of Paediatrics and Child Health, The Children's Hospital at Westmead and the Westmead Hospital, Westmead, NSW, 2145, Australia;(3) Orthopaedic Research and Biotechnology, University of Sydney, Disciple of Paediatrics and Child Health, The Children's Hospital at Westmead, Westmead, Australia;(4) Department of Biological Science, University of Macquarie Sydney, Sydney, Australia |
| |
Abstract: | Background There is an emerging interest in utilizing local and systemic administration of bisphosphonates in orthopedics. The primary
objective of this study was to use 99mTc-pamidronate (99mTc-PAM) as a tool and compare bone and tissue uptake by local versus systemic administration.
Methods
99mTc-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 99mTc PAM.
Results Bone uptake of 99mTc-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 99mTc-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.
Conclusions The results indicate that the bone uptake of 99mTc-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. |
| |
Keywords: | |
本文献已被 ScienceDirect SpringerLink 等数据库收录! |
|