Synthesis and evaluation of zoledronate acid derivative labeled by 68Ga for PET diagnosis of bone diseases

Bone metastases are one of the main consequences of some cancers, such as breast, lung and prostate cancers, which are accompanied by severe pain in the bone area. Gallium-68 radioisotope with a half-life of 68 minutes is one of the most suitable options in Positron emission tomography (PET) is used in nuclear medicine. In this study, one of the zoledronic acid derivatives was synthesized as a bone-seeking agent and then attached to the DOTA chelator. The DOTA-ZOL compound was finally used for 68Ga labeling. All synthesized products were identified by FT-IR, NMR and MASS spectroscopies. The radionuclide purity of gallium-68 was calibrated by HPGe detector and determined with a multi-channel analyzer (99.9%). The radiochemical purity of the generator wash solution was investigated by thin layer chromatography using two different solutions (100%). Labeling of the prepared complex with 68Ga was performed by DOTA chelator and the radiochemical purity of the final complex at the optimized conditions (pH=4, temperature 98ºC, reaction time: 30 min) was examined by thin layer chromatography technique and determined about 97%. The results of this study showed that 68Ga-DOTA-ZOL is a suitable diagnostic radiopharmaceutical for imaging bone metastases by PET method.