Radionecrosis of the Anterior Skull Base as a Consequence of Sinonasal Malignant Tumor Management: Diagnosis, Prevention, and Management

Objectives: Treatment of sinonasal malignant tumors is based on surgery followed by radiotherapy, and eventually combined with chemotherapy. A late complication of this treatment is cerebral radionecrosis. The aims of this study are to: (1) highlight the main diagnosis criteria of radionecrosis, (2) identify any risk factors, and (3) determine methods of prevention.

Methods: Retrospective series of patients with AC, ON, and melanoma who were treated in a single institution from 2001 to 2009. All patients underwent anterior skull base resection by endoscopic, transfacial, or transbasal approaches. The dural plasty consisted of two layers of fascia lata (one intradural and one extradural) for the anterior or endoscopic approaches and of pericranium. Then, 48 to 70 grays were delivered to the tumoral site. Minimal follow-up was 2 years after radiotherapy.

Results: Sixty patients were treated, but only 49 files could be analyzed (more than 30 were operated on with an endoscopic approach). Nine patients presented an anterior skull base radionecrosis. For six, radionecrosis remained asymptomatic and diagnosed only on control MRI. However, in three patients, radionecrosis triggered seizures. Although there was no CSF leak, the dural plasty was done all over again by an external approach. Three risk factors were identified: diabetes, anticoagulant therapy, and dural resection.

Conclusion: Radionecrosis is a potentially serious complication, for which no specific treatment has been established. Risk factors are diabetes, age, and possibly radiotherapy dose. Dose of adjuvant radiotherapy should be discussed in light of the tumor stage and also of the patient's condition.