Clinical comparison of technetium-99m-EC, technetium-99m-MAG3 and iodine-131-OIH in renal disorders.
Technetium-99m-ethylenedicysteine has recently been developed for renal function studies. The pharmacokinetics of 99mTc-EC were studied by constant infusion technique and compared with 99mTc-MAG3 and 131I-OIH in 11 patients with various renal disorders.


METHODS
After giving a 7.4 MBq 131I-OIH and 90-110 MBq 99mTc-EC or 99mTc-MAG3 bolus, a constant infusion (1MBq/ml 99mTc-agent and 0.07 MBq/m 131I-OIH was started. Sixteen blood and five urine samples were obtained over three hr.


RESULTS
The renal clearance of 99mTc-EC was higher than that of 99mTc-MAG3. The 99mTc-EC/OIH and 99mTc-MAG3/OIH ratios were 0.75 +/- 0.05 and 0.55 +/- 0.10 (p = 0.00087), respectively. The distribution volume of 99mTc-EC was also higher than that of 99mTc-MAG3 (15722 +/- 4644 and 9509 +/- 2788 ml/1.73m2, respectively; p = 0.072). The 99mTc-EC/OIH and 99mTc-MAG3/OIH distribution volume ratios were 1.03 +/- 0.14 and 0.55 +/- 0.10, respectively (p = 0.0003). The 60-min excretion values of 99mTc-EC and 99mTc-MAG3 were compared to that of OIH. The 99mTc-EC/OIH and 99mTc-MAG3/OIH excretion ratios were 0.96 +/- 0.06 and 1.07 +/- 0.10, respectively (p = 0.162). The protein binding of 99mTc-EC and OIH were found to be 34% +/- 4 and 66% +/- 5, respectively (p < 0.0001). The red cell binding of 99mTc-EC was negligible (3% +/- 1.2) in comparison to OIH (27% +/- 3; p < 0.0001).


CONCLUSIONS
This limited study demonstrates the pharmacokinetic and renal clearance properties of 99mTc-EC. This agent has good potential for renal function evaluation.
Kabasakal
L
L
Department of Nuclear Medicine, Cerrahpaşa Medical Faculty of Istanbul University, Turkey.
Turoğlu
H T
HT
Onsel
C
C
Ozker
K
K
Uslu
I
I
Atay
S
S
Cansiz
T
T
Sönmezoğlu
K
K
Altiok
E
E
Isitman
A T
AT
D000293:Adolescent; D000328:Adult; D003545:Cysteine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D007465:Iodohippuric Acid / Q000493:pharmacokinetics*; D007674:Kidney Diseases / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D011877:Radionuclide Imaging; D017263:Technetium Tc 99m Mertiatide / Q000493:pharmacokinetics*
D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; C073806:technetium Tc 99m-ethylenedicysteine; D007465:Iodohippuric Acid; D017263:Technetium Tc 99m Mertiatide; D003545:Cysteine