Expression of Urine Kidney Injury Molecule-1 of Tumor Patients Predicts Acute Kidney Injury During Gama-Ray Stereotactic Radiosurgery

Objective:To assess whether urine kidney injury molecule-1 (KIM-1) could predict acute kidney injury in the tumor patients treated with gama-ray stereotactic radiosurgery (Gama knife).Methods:100 tumor patients admitted to our hospital from May 2007 to Nov 2007 were treated with Gama knife radiotherapy.AKI was defined as the absolute increment over 0.3 mg/dl from baseline or 50% increase in serum creatinine according to the RIFLE criteria.All these patients used the low-osmolar nonionic contrast medium before treated with Gama knife.The clinical features of all patients were observed.Urine KIM-1 was measured by ELISA.Receiver operating characteristic curve (ROC)and area under the curve (AUC) were described.Results:Of all patients,acute kidney injury group included 25 patients and no acute kidney injury group included 75 patients.The urinary KIM-1 levels in AKI group were significantly higher at 12 h、24 h、48 h after intravenous injection of contrast medium and 7d after treated with Gama knife compared with no AKI group.The urine KIM-1 values were also significantly different between AKI group and no AKI group at 12 h、24 h、48 h after intravenous injection of contrast medium when normalized to urinary creatinine concentration.On diagnostic performance testing,urine KIM-1/urinary creatinine value demonstrates an area under the receiver operating characteristic curve of 0.709(95% CI 0.585～0.832,P0.05) to predict AKI at the time point of 12h after contrast injection.Conclusion:Urine KIM-1 measurement may predict onset of acute kidney injury in the tumor patients treated with Gama knife.It is a relatively more sensitive early biomarkers than serum creatinine in tumor patients.