Purpose: To determine a valid and practical routine for glomerular filtration rate measurement in gynaecologic cancer patients.
Material and methods: The established method, endogenous creatinine clearance, was compared to 51Cr-EDTA clearance and contrast medium clearance in 68 women with various gynaecologic carcinomas. Contrast medium clearance was determined in association with conventional urography (iohexal 300 mg I/ml, 40 ml) for evaluation of urinary tract involvement by the tumour. Automated X-ray fluorescence analysis equipment was used for the plasma analysis of iohexol and clearance calculations. Endogenous creatinine clearance and 51Cr-EDTA clearance were determined according to standard routine procedures. Simultaneous determinations of contrast medium clearance and 51Cr-EDTA clearance (n = 33), contrast medium clearance and endogenous creatinine clearance (n = 50), as well as 51Cr-EDTA clearance and endogenous creatinine clearance (n = 30) were compared.
Results and conclusion: The mean differences were -2.8 (SD 6.6), -1.8 (SD 22.3), and 2.7 (SD 18.3) ml/min/1.73 m2, respectively. It is concluded that contrast medium clearance is as adequate as 51Cr-EDTA clearance for glomerular filtration rate measurement. We suggest that contrast medium clearance should replace endogenous creatinine clearance, especially in patients referred for urography.