Pharmacokinetics of 188Re-HEDP in cancer patients with osseous metastases / 中华核医学杂志

ABSTRACT

Objective To investigate the biodistribution,excretion and other pharmacokinetics,of 188Re-1-hydroxy-1,1-ethylidene disodium phosphonate (HEDP) in cancer patients with osseous metastases who were suffering form bone pain. Methods A single dose (20,30,40,and 50 MBq/kg,10 patients in every group) of 188Re-HEDP was administered as a bolus injection,meanwhile dynamic images on patient's chest were collected for 30 min. Anterior and posterior whole-body images were obtained at 1,2,4,5,12,24,36,48,60 and 72 h after injection of 188Re-HEDP. By region of interest (ROI) technology,the curve of time-background corrected counts of left cardiac ventricle could be generated,and the background-corrected counts of various organs and total whole body could be calculated as a geometric mean using the anterior and posterior scans,and transformed to the percentage injected dose ( % ID). Urine was collected after injection of 188Re-HEDP. Counts of urine were measured by γ counter. Analysis of variance and t-test were used. Results Linear relationship of metabolism of 188Re-HEDP was observed in the doses from 20 to 50 MBq/kg,with correlation coefficient r2 = 0. 9376. A two-compartment model was the best fit for metabolism of 188Re-HEDP with the parameters median area under curve (AUC) 3.32 × 105,3.97 × 105,7.83 × 105,8.58 ×105,respectively; median α 0.06,0.05,0.04,0.06 respectively; median β 1.16 ×10-3,1.16 × 10-3,1.03 × 10-3,1.15 × 10 -3 respectively; median A 3591.21,4858.23,5642. 48,4167.05 respectively; median B 293.97,352.95,614.41,1063.82 respectively; median T1/2(α) 12.51,12.83,15.41,12.02 min respectively; median T1/2(β) 595.47,596.50,673.09,600.93 min respectively in the doses of 20,30,40and 50 MBq/kg. 188Re-HEDP was taken up mainly by bone up to 40% ID at 4 h. Urine profile showed that 66.79 % ID was eliminated within 24 h,being its 74% collected along the first 5 h after-administration.Conclusions In the doses of 20,30,40 and 50 MBq/kg,metabolism of 188Re-HEDP presented linear model. Pharmacokinetics of 188 Re-HEDP followed a two-compartment model administrated by blood vessel.Following injection,188 Re-HEDP was taken up mainly by bone and excreted by uropoietic system.