Evaluation of Dosing Procedures of Chemotherapy Treatment (Carboplatin) With the Contrast Agent Iohexol

PRIMARY OBJECTIVES: I. Evaluate the success of targeting a carboplatin area under the curve (AUC) with our current approach to dosing carboplatin. II. Assess the performance of Cockcroft-Gault (CG), four-variable Modification of Diet in Renal Disease (MDRD-4), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) based on isotope dilution mass spectrometry (IDMS) calibrated serum creatinine in predicting measured glomerular filtration rate (mGFR) in patients with cancer. III. Define the relationship of mGFR and carboplatin clearance in patients with cancer. SECONDARY OBJECTIVES: I. Evaluate the divergence of estimated (e)GFR from mGFR based on patient demographic and other characteristics, thus identifying those most likely to benefit from determination of mGFR over use of eGFR. II. Determine the success rate of achieving the target carboplatin AUC in patients in whom the carboplatin dose is capped. III. Evaluate the relationship between carboplatin exposure and toxicity. IV. Assess the ability of markers other than creatinine in pre-treatment serum to better estimate kidney function in patients with cancer. OUTLINE: Patients receive iohexol intravenously (IV) over 30-60 seconds. Patients then receive standard of care carboplatin IV. Patients also undergo collection of 7-8 blood samples for analysis. After completion of study, patients are followed up for 3-4 weeks.