Introduction:
The aim of this study was to find out if 90Y could form a stabile complex with meso-2,3-dimercaptosuccinic acid (DMSA) and if 90Y-DMSA may have potential for tumor therapy in the palliative treatment of bone metastases.
Methods:
The preparing of 90Y-DMSA was carried out by varying experimental parameters, such as ligand concentration, pH, time, and temperature of the reaction, in order to maximize the labeling yield. Analysis of the complexes enclosed the radiochemical quality control (instant thin-layer chromatography, paper chromatography, and high-performance liquid chromatography), determination of pharmacokinetical parameters as well as biodistrbution study in health male Wistar rats. In vitro stability of the complexes was tested too.
Results:
90Y-DMSA could be prepared in high yields (>95%) under optimized conditions of reaction. Stability studies in saline and human serum in vitro showed no significant release of activity from the ligand over 24 hours and 10 days, respectively. The preliminary biodistribution results in rat at 2 hours indicated that 90Y-DMSA, at both pH levels, was significantly retained into bone. The uptake in the kidneys was lower for 90Y-DMSA at pH 8.0 then at pH 3.0. The retention in other organs was negligible.
Conclusions:
90Y complexes could be made with ease with DMSA. 90Y-DMSA was obtained in good yield and was found to be very stable. A promising biodistribution result of this complex pointed at potential in the palliative treatment of bone metastases.
