Evaluation of glomerular filtration rate estimation methods - renal scintigraphy 99MTC - diethylenetriamine pentaacetic acid (99MTC-DTPA) and cockcroft-gault equation

Abstract

Introduction. An accurate staging of chronic kidney disease (CKD) is very important in the evaluation and treatment of kidney function impairment. The most common method of assessing patients’ estimated (eGFR) is by indirect calculations like Cockcroft-Gault formula. On the other hand, direct methods of measured (mGFR) calculation exist, one of which is renal scintigraphy 99mTc-DTPA, although it is expensive; therefore, not widely used in all clinical settings. Aim The aim is to analyse and compare the estimations of two glomerular filtration rate measurement methods, Cockcroft-Gault (CG) formula and Dynamic renal scintigraphy (99mTc-DTPA). Methods. Clinical data was collected of patients who underwent Dynamic Renal Scintigraphy with 99mTc-DTPA in Lithuanian University of Health Sciences Kaunas Clinics (LSMU KC), Radiology clinic, Nuclear medicine department during the period of April 2016 to October 2017 using a scintillation camera (Philips Brightview, USA). The total of 207 case-reports were collected. GFR was estimated simultaneously in 207 patients using the following methods: Gates’ method (mGFR), Cockcroft-Gault equation (eGFR). Clinical data variables such as: gender, age, weight, height, body mass index, serum creatinine were used. Serum creatinine was measured using calibrated Jaffe method. Patient’s GFRs were categorized according to the Kidney Disease Improving Global Outcomes (KDIGO) CKD staging G1-G5. Using Gates’ method as a reference method, the estimations of GFR with Cockcroft-Gault were compared with that of Gates’. Paired Student t-test was used for comparing group means. Pearson’s correlation coefficient and Pearson’s Chi-square test were used for analyzing GFR results. The received data is provided as an arithmetic mean, ± standard deviation. The confidence level of 0.95 was considered to be satisfactory, so the value of p <0.05 is presented as showing a statistically signif[...].