title: Radiation dose estimates of 186Re-hydroxyethylidene diphosphonate for palliation of metastatic osseous lesions: an animal model study.
abstract: A common complication in patients with breast or prostate cancer is bone metastases causing pain. New radionuclide therapy methods have recently been proposed for palliation, including 186Re-hydroxyethylidene diphosphonate (186Re-HEDP). This paper reports on the local development of 186Re-HEDP and the biodistribution studied in animals for eventual use in patients. Adult dose was computed assuming a 70 kg standard man. The 186Re was labelled to HEDP using standard techniques. The biodistribution in five Chacma baboons (Papio ursinus) was studied. Doses ranging from 39.4 to 44.9 MBq kg(-1) (mean 43.6 +/- 2.8 MBq kg[-1]) were administered, corresponding to an adult human dose of 2960 MBq (80 mCi). Whole-body images of the animals were obtained with a dual-headed scintillation camera on an hourly basis for 6 h post-injection and then daily for 3 days. The bone, soft tissue, kidneys and urinary bladder were considered source organs and data from these organs were used in a compartmental model to obtain the mean residence times of the radionuclide in the different source organs. Radiation dose estimates for 186Re-HEDP were subsequently obtained with the MIRDOSE 3 program. The estimated absorbed radiation doses to some of the organs (expressed in mGy MBq[-l]) were as follows: bone surface 1.69; kidneys 0.09; liver 0.04; ovaries 0.04; red marrow 0.75; total body 0.12; urinary bladder wall 0.43. 186Re-HEDP yielded an effective dose of 0.17 mSv MBq(-1). The radiation dose delivered to the bone marrow in this study did not cause any detrimental effect to the baboons, indicating that locally produced 186Re-HEDP is suitable for clinical use.
authors.affiliation: Department of Biophysics, University of the Orange Free State, Bloemfontein, South Africa.
authors.forename: A
authors.initials: A
authors.lastname: van Aswegen
authors.forename: A
authors.initials: A
authors.lastname: Roodt
authors.forename: J
authors.initials: J
authors.lastname: Marais
authors.forename: J M
authors.initials: JM
authors.lastname: Botha
authors.forename: H
authors.initials: H
authors.lastname: Naudé
authors.forename: M G
authors.initials: MG
authors.lastname: Lötter
authors.forename: L
authors.initials: L
authors.lastname: Goedhals
authors.forename: M J
authors.initials: MJ
authors.lastname: Doman
authors.forename: A C
authors.initials: AC
authors.lastname: Otto
mesh_terms: D000328:Adult; D000818:Animals; D001859:Bone Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D001842:Bone and Bones / Q000378:metabolism; D001943:Breast Neoplasms / Q000532:radiotherapy; D012968:Etidronic Acid; D005260:Female; D006801:Humans; D007668:Kidney / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D010166:Palliative Care; D010215:Papio; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics / Q000627:therapeutic use; D012211:Rhenium / Q000493:pharmacokinetics / Q000627:therapeutic use; D014018:Tissue Distribution; D001743:Urinary Bladder / Q000378:metabolism
chemical_list: D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; C101598:rhenium-186 HEDP; D012211:Rhenium; D012968:Etidronic Acid