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.

Context: 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.

Aims: 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.

Settings And Design: This is a prospective, descriptive study.

Subjects And Methods: 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.

Statistical Analysis Used: 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.

Results: 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).

Conclusions: 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.