The document discusses the glomerular filtration rate (GFR) as a standard measure of renal function, detailing its calculation through plasma clearance and indications for its use, including assessing kidney function before chemotherapy. It outlines patient preparation, procedures for measuring GFR, and provides case studies illustrating normal and abnormal results. The conclusion emphasizes GFR's importance in detecting renal failure and evaluating donor suitability for kidney transplantation.