Preparation of a rhenium-188 labeled bisphosphonate for bone pain palliation therapy

Abstract

In order to reduce the pain due bone metastases a last generation bisphosphonate, 2-(3-pyridinyl)-1-hydroxyethane diphosphonic acid, was labeled with 188Re and investigated further. Labeling was performed at 95 °C for 15 min. The stability of radioconjugate was checked in human serum at 37 °C and biodistribution was studied in balb/c mice. Labeling yield of ≥98 % was obtained corresponding to a specific activity of 46 MBq/µmol. The radioconjugate showed good stability in human serum. Our main achievement was high bone uptake (4.24 ± 0.12 % ID/g at 24 h post injection) which may therapeutically be beneficial for the palliation of painful bone metastasis.