Bevacizumab as a treatment option for radiation-induced cerebral necrosis.

Radiation necrosis of normal CNS tissue represents one of the main risk factors of brain irradiation, occurring more frequently and earlier at higher total doses and higher doses per fraction. At present, it is believed that the necrosis results due to increasing capillary permeability caused by cytokine release leading to extracellular edema. This process is sustained by endothelial dysfunction, tissue hypoxia, and subsequent necrosis. Consequently, blocking the vascular endothelial growth factor (VEGF) at an early stage could be an option to reduce the development of radiation necrosis by decreasing the vascular permeability. This might help to reverse the pathological mechanisms, improve the symptoms and prevent further progression. A patient with radiationinduced necrosis was treated with an anti-VEGF antibody (bevacizumab), in whom neurologic signs and symptoms improved in accordance with a decrease in T1-weighted fluid-attenuated inversion recovery signals. Our case report together with the current literature suggests bevacizumab as a treatment option for patients with symptoms and radiological signs of cerebral necrosis induced by radiotherapy.

Cystatin C - a fast and reliable biomarker for glomerular filtration rate in head and neck cancer patients.

PURPOSE: Determination of renal function is a prerequisite for planning therapy in cancer patients. Limitations of creatinine as marker for the glomerular filtration rate (GFR) led to the proposal of cystatin C as a more accurate biomarker especially in mild renal insufficiency or in patients with low muscle mass. We compared the accuracy of cystatin C- and creatinine-based equations to estimate GFR in head and neck cancer (HNC) patients receiving platinum-based radiochemotherapy. PATIENTS AND METHODS: The study population consisted of 52 HNC patients (GFR range, 37-105 mL/min/1.73 m(2) complemented by 17 patients with known renal insufficiency (GFR range, 10-60 mL/min/1.73 m(2)). Intraclass correlation coefficients were calculated between the reference method (51)Cr-EDTA clearance and estimated GFR by creatinine clearance and equations based on creatinine (Cockroft-Gault, modification of diet in renal disease (MDRD), Wright) or cystatin C (Larsson, Dade-Behring, Hoek). In addition, sensitivity and specificity to discriminate GFR > 60 mL/min/1.73 m(2) were evaluated by receiver operating characteristic curve (ROC). RESULTS: The highest correlation coefficients were found for the cystatin C-based estimates in comparison with creatinine-based estimates or creatinine clearance, even though Bland-Altman plots revealed GFR overestimation for all equations tested. The cystatin C-based Hoek formula exhibited the highest overall precision and accuracy. GFR of < 60 mL/min/1.73 m(2) was assumed as a cut-off for chemotherapy. ROC analyses revealed the highest AUC to predict a GFR > 60 mL/min/1.73 m(2) for the creatinine-based Wright formula, closely followed by the MDRD formula and cystatin C-based equations of Larsson, Dade-Behring, and Hoek. CONCLUSION: Cystatin C-based GFR estimates showed the overall strongest correlation to the reference method. Thus, we recommend cystatin C for GFR estimation in HNC patients as an alternative method to the estimated creatinine clearance in clinical practice.