4. Renal function: Serum creatinine ≤ 1.5 x upper limit of normal for age and 24-hour urine creatinine clearance > 70 mL/min/1.73 m2 by radionuclide glomerular filtration rate (GFR); or GFR > 70 mL/min/1.73 m2 by radionuclide GFR.