Preparation of [186Re]Re-DMSA and its bio-distribution studies.

99mTc(V)-DMSA is widely used for imaging medullary carcinoma and hence 186/188Re(V)-DMSA is suggested as a potential agent for treating medullary carcinoma. In the present paper, we report the work carried out for the preparation of [186Re]Re(V)-DMSA and it's bio-distribution studies in Wistar rats. The complex was prepared by reducing 186Re (100 micrograms, 0.54 microM, approximately 150 MBq) in the presence of DMSA (2 mg, 11 microM) with stannous chloride (0.4 mg, 2.2 microM) in acidic medium at pH 2. The reaction was taken to completion by heating the complex in a boiling water bath for 30 min. Bio-distribution studies carried out revealed that pharmacological behaviour of 186Re(V)-DMSA is similar to that of 99mTc(V)-DMSA except that the kidney uptake is marginally higher. The kidney uptake reduced significantly when the pH of the complex was adjusted to 8 prior to injection. The in vitro stability studies of this complex suggest that the product formed is stable and could be used for clinical trials.