Alteration of 99mTc-DMSA biodistribution in glomerulonephritis.

BACKGROUND The aim of this study was to assess the relation between (99m)Tc-DMSA biodistribution and its reliability as a marker of renal function in patients with glomerular kidney diseases. MATERIAL AND METHODS Sixty-seven patients involved in this study were classified into two groups according to (99m)Tc-DTPA clearance and serum creatinine values: the 1st group consisted of 42 patients without renal failure while the 2nd group included 25 patients with renal failure. (99m)Tc-DMSA biodistribution was determined by measuring kidney, blood and urine activity at 2 h and 4 h. RESULTS The results, compared with those of 23 healthy volunteers, indicated the quantitative alteration of (99m)Tc-DMSA distribution in both glomerulonephritis patient groups. In reference to the control mean values of 2 h and 4 h, in patients without renal failure, kidney activity was found decreased to 52% and 57%, while the blood activity increase of 37% and 44% was recorded together with the urine activity increase of 38% and 23%. In patients with renal failure the alterations of renal and blood activity were more remarkable, but the urine loss was found to be unchanged. CONCLUSIONS It is suggested that these biodistribution changes originate mainly from tubular impairment. However, in glomerulonephritis patients, altered glomerular filtration might considerably affect biodistribution of this radiopharmaceutical and limits its suitability for precise quantitative estimation of renal function.