Analytical and radioanalytical quality control of purity and stability of radiopharmaceutical compound Re-186 HEDP for bone metastases pain palliation.

The nuclear properties of 186gRe make it a useful agent for radionuclide therapy and imaging. The coordination compound [186Re]Re-HEDP has proved to be a successful bone seeking agent for palliation of metastatic bone pain. Chemical, radiochemical and radionuclidic purity of commercial radiopharmaceutical [186gRe]Re-HEDP have been checked by means by gamma - and beta -spectrometries, INAA and paper radiochromatography. The results indicate a good radionuclidic purity, with levels of contamination from the short-lived 188Re well below the required specifications. After injection of the radiopharmaceutical, the radiochemical measurements conducted in vivo, on biological matrices, blood, plasma and urine, have shown that, entering the systemic circulation, 186gRe dissociates from the bis-phosphonate complex as hydrosoluble [186gRe]ReO4-, and the two chemical species follow different biokinetics.