Synthesis of DTPA-attached estradiol derivative and determination of its radiopharmaceutical potential

Biber F., ÜNAK P., Enginar H., Ertay T., Medine E., Tasci C., ...More

JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY, vol.266, no.3, pp.445-454, 2005 (SCI-Expanded) identifier identifier


An estrogen derivative, beta-estradiol or 1,3,5,(10)-estratriene-3,17 beta-diol) attached to diethylenetriamine pentaacetic acid (DTPA) was synthesized in six experimental steps. At the end of these steps, a DTPA-attached estradiol derivative called deoxy-demethyl homoestradiolyl-diethylenetriamine-pentaacetic acid (ESTDTPA) was obtained. The synthesized compounds were labeled with Tc-99m. Thin layer radio chromatography (TLRC) was used to determine radiochemical yields and stabilities.Structural investigations confirmed the structures. The labeling yield was satisfactory (about 95%), and Tc-99m-ESTDPTA was stable in neutral medium at room temperature for 5 hours. Biodistribution studies were performed on normal and DMBA-induced, tumor bearing female Albino Wistar rats. The activity per gram tissue was calculated, and time-activity curves were plotted. ESTDTPA uptake by uterus reached a level of 20.73% dose/g, showing a maximum within 5 minutes after injection. Ovary and breast showed similar biodistribution profiles. The kidneys, which are the primary organs of metabolism and excretion of estrogen, showed a high Tc-99m-ESTDTPA uptake. The imaging studies were performed on normal and tumor bearing female Albino Wistar rats using a Camstar XR/T gamma-camera. Gamma-scintigraphy studies showed that tumors could be well visualized in a few minutes and clearly differentiated from other organs, such as bladder and liver by 24 hours.