A prospective study to compare the measured glomerular filtration rate compared to estimated glomerular filtration rate in patients undergoing definitive chemoradiation, with platinum agents for various malignancies.

Abstract

Renal function assessment is of paramount importance before using the platinum agents especially cisplatin. Glomerular filtration rate (GFR) estimation by diethyl-triamine-penta-acetic acid (DTPA) scan (measured GFR [mGFR]) is considered gold standard. The aim of this study is to know if we can replace the mGFR with the GFR estimation with Cockcroft-Gault formula (eGFR) in patients undergoing chemoradiation. This is a prospective, descriptive study. Patients who are planned for definitive chemoradiation will be eligible for the study. Renal function will be measured DTPA scan and Cockcroft-Gault (CG) formula. Subgroup analysis based on the weight, age, and sex will be done. Demographic and renal function parameters were analyzed using summary measures. To test the significance of the difference between mGFR and cGFR, a paired t-test will be used; to look for an association between various estimates of renal function, the Pearson's correlation coefficient will be calculated using a two-tailed test. Median mGFR of patients was 82.7 (range: 65-125 ml/min, standard deviation [SD] =14.0 ml/min) while the median eGFR as per the CG formula was 83.9 ml/min (range: 37-137 ml/min, SD = 24.4 ml/min). The median mGFR was only 1.2 ml/min lesser when measures by the CG formula with no significance difference between them (P = 0.66, 95% confidence interval: -4.5-6.3). We concluded that in resource-limited setting eGFR using CG formula can replace mGFR, especially in patients with age <60 years. Although weight did not showed a significant difference by two methods, a study with large sample is needed to confirm the result.