Bone uptake studies in rabbits before and after high-dose treatment with 153Sm-EDTMP or 186Re-HEDP.
The aim of this animal study was to measure the bone uptake of (99m)Tc-hydroxymethylene diphosphonate (HDP) before and after high-dose treatment with (153)Sm-ethylenediaminetetramethylenephosphonate (EDTMP) or (186)Re-(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 (99m)Tc-HDP was performed on 12 rabbits before and 8 wk after radionuclide therapy with 1,000 MBq of either (153)Sm-EDTMP or (186)Re-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 (153)Sm-EDTMP (n = 6), no differences could be proven for the bone uptake of (99m)Tc-HDP at 24 h after injection before and after therapy (51.1% +/- 5.5% vs. 48.0% +/- 6.1%, P > 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 (186)Re-HEDP: Bone uptake (44.8% +/- 6.7% vs. 40.4% +/- 4.9%, P > 0.05) and urinary excretion revealed no significant differences before and after treatment.


CONCLUSIONS
No significant impairment of bone uptake of (99m)Tc-HDP could be observed 8 wk after high-dose radionuclide bone therapy. Because both the biokinetic data obtained for (186)Re-HEDP and (153)Sm-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 (186)Re-HEDP or (153)Sm-EDTMP.
Brenner
Winfried
W
Clinic of Nuclear Medicine, University Hospital Kiel, Kiel, Germany. winbren_2000@yahoo.com
Kampen
Willm Uwe
WU
Brümmer
Corinna
C
von Forstner
Corinna
C
Zuhayra
Maaz
M
Czech
Norbert
N
Muhle
Claus
C
Henze
Eberhard
E
D000818:Animals; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism*; D003238:Connective Tissue / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D012968:Etidronic Acid / Q000008:administration & dosage*; D005260:Female; D009942:Organometallic Compounds / Q000008:administration & dosage*; D009943:Organophosphorus Compounds / Q000008:administration & dosage*; D011817:Rabbits; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012211:Rhenium / Q000008:administration & dosage*; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives* / Q000493:pharmacokinetics* / Q000652:urine; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D014915:Whole-Body Counting
D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D019275:Radiopharmaceuticals; C101598:rhenium-186 HEDP; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D012211:Rhenium; C061972:samarium Sm-153 lexidronam; D012968:Etidronic Acid; D013669:Technetium Tc 99m Medronate