Parathormone and³²P Therapy in Prostatic Cancer with Bone Metastases

Therapeutic Radiopharmaceuticals

“…154,155,215,216 In contrast, the β-particles emitted by 153 Sm-EDTMP located on bone surfaces following administration of extremely high doses of 153 Sm-EDTMP (i.e., .1.0 mCi/kg or 37 MBq/ kg) were found to be too low for complete ablation of the normal bone marrow in dogs. 177,218 The choice of DOTMP as the chelating agent (and not EDTMP) to deliver 166 Ho to the skeleton was made based on the mass of material to be administered. The use of sufficient quantities of 166 Ho (i.e., g2 Ci or 74 GBq) that are required for marrow ablation would require several milligrams of holmium target.…”

“…The long-range of these β particles (Table ) produces excessive marrow suppression when compared to 153 Sm−EDTMP. Since these highly penetrating β particles destroy bone marrow cells remote from the surface of the bone where 166 Ho−DOTMP deposits, it can be used for eradication of multiple myeloma cells and the normal stem cells located in the marrow space. ,,, In contrast, the β-particles emitted by 153 Sm−EDTMP located on bone surfaces following administration of extremely high doses of 153 Sm−EDTMP (i.e., ≫1.0 mCi/kg or 37 MBq/kg) were found to be too low for complete ablation of the normal bone marrow in dogs. , …”

Targeted radionuclide therapy for bone metastases

“…Radiophosphorus uptake was increased during the rebound phase of increased osteoblastic activity following PTH withdrawal (Tong 1971).…”

Cancer therapy using bone-seeking isotopes

“…An alternative pharmacological intervention involves the administration of parathyroid hormone (PTH) to accelerate bone resorption (Tong 1971). PTH withdrawal stimulates a rebound increase in osteoblastic activity, resulting in increased radiophosphorus uptake.…”