PT - JOURNAL ARTICLE AU - Brenner, Winfried AU - Kampen, Willm Uwe AU - Brümmer, Corinna AU - von Forstner, Corinna AU - Zuhayra, Maaz AU - Czech, Norbert AU - Muhle, Claus AU - Henze, Eberhard TI - Bone Uptake Studies in Rabbits Before and After High-Dose Treatment with <sup>153</sup>Sm-EDTMP or <sup>186</sup>Re-HEDP DP - 2003 Feb 01 TA - Journal of Nuclear Medicine PG - 247--251 VI - 44 IP - 2 4099 - http://jnm.snmjournals.org/content/44/2/247.short 4100 - http://jnm.snmjournals.org/content/44/2/247.full SO - J Nucl Med2003 Feb 01; 44 AB - The aim of this animal study was to measure the bone uptake of 99mTc-hydroxymethylene diphosphonate (HDP) before and after high-dose treatment with 153Sm-ethylenediaminetetramethylenephosphonate (EDTMP) or 186Re-(tin)1,1-hydroxyethylidene diphosphonate (HEDP) to prove or disprove post-therapeutic alterations of bone uptake of radiolabeled bisphosphonates. Methods: Quantitative bone scanning using 100 MBq 99mTc-HDP was performed on 12 rabbits before and 8 wk after radionuclide therapy with 1,000 MBq of either 153Sm-EDTMP or 186Re-HEDP. Whole-body images were acquired at 3 min, 3 h, and 24 h after injection, and the activities for the whole body, urinary bladder, and soft tissue were measured by region-of-interest technique. From these data, bone uptake was calculated as initial whole-body activity minus urinary excretion and remainder soft-tissue activity. Results: In animals treated with 153Sm-EDTMP (n = 6), no differences could be proven for the bone uptake of 99mTc-HDP at 24 h after injection before and after therapy (51.1% ± 5.5% vs. 48.0% ± 6.1%, P &gt; 0.05). There were also no significant differences for the remainder soft-tissue activities and the urinary excretion rates before and after therapy. Similar results were obtained in rabbits treated with 186Re-HEDP: Bone uptake (44.8% ± 6.7% vs. 40.4% ± 4.9%, P &gt; 0.05) and urinary excretion revealed no significant differences before and after treatment. Conclusion: No significant impairment of bone uptake of 99mTc-HDP could be observed 8 wk after high-dose radionuclide bone therapy. Because both the biokinetic data obtained for 186Re-HEDP and 153Sm-EDTMP and the myelotoxic effects were quite similar in rabbits to those in patients, it seems justifiable to expect the same result (i.e., no significant alteration of bone uptake of radiolabeled bisphosphonates) in patients undergoing a second radionuclide therapy within 2–3 mo after standard treatment with 186Re-HEDP or 153Sm-EDTMP.