Estimation of prevalence of pretreatment renal insufficiency and use of mathematical formulae to assess the renal dysfunction in patients of head and neck cancers undergoing concurrent chemoradiotherapy in Northern India

Background: Cisplatin (CDDP)-based concurrent chemoradiotherapy (CRT) is the standard of care in locally advanced head and neck cancers (HNCs). CDDP, a known nephrotoxic drug, has been administered in three different protocols. Baseline renal function needs to be known before CRT. Renal function can be measured directly by measuring the measured glomerular filtration rate (mGFR) using radioisotope and indirectly by either serum creatinine (SCR) levels or estimated GFR (eGFR) using mathematical formulae “abbreviated modification of diet in renal disease (aMDRD)” and “Cockcroft–Gault (CG).” The present study was performed to see the prevalence of pretreatment renal insufficiency (RI) in HNC patients and to find a realistic method using CG and aMDRD formulae for assessing RI instead of doing mGFR and to compare the nephrotoxicity in three CDDP protocols. Materials and Methods: The study was carried out between January 2005 and December 2006. Consecutive patients of HNC undergoing RT/CRT were included. Renal function using parameters SCR, mGFR, and eGFR using CG and aMDRD formulae was estimated for pre- and post-treatment and during follow-up. Results: Of 295 eligible patients, baseline prevalence of RI was in 17% by mGFR, 6% by SCR, 13% by aMDRD, and 41% patients by CG formula. aMDRD correlated better than CG with the mGFR. Of the 145 patients of CRT, pretreatment RI was seen in 9% by aMDRD and 30% by CG formula as compared to 12% by mGFR and post treatment RI was seen in 12% by aMDRD and 43% by CG formula. All the three CDDP protocols showed similar fall in GFR post treatment, and late renal injury at 6 months was seen in 2%, 4%, and 3%, respectively. Conclusions: RI exists in HNC patient. RI assessment by SCR is inadequate and should be done by eGFR estimation using aMDRD or CG formula if not able to do mGFR. Different CDDP protocols have similar nephrotoxicity.