Linear Accelerator Mask-Based Radiosurgery for Trigeminal Neuralgia: Prospective Evaluation of 50 Patients.

Abstract

Trigeminal neuralgia (TN) resistant to pharmacologic treatment can be treated with microvascular decompression, percutaneous procedures, or radiosurgery. Regarding radiosurgery, there is variability in target definition, dose selection, radiation delivery and positioning, and immobilization. This observational prospective study included patients with TN treated with 90 Gy prescribed to an anterior cisternal isocenter, delivered with a TrueBeam LINAC, under mask immobilization, Novalis couch positioning, and ExacTrac X-ray and infrared positioning and motion monitoring. Treatment response, intensity and frequency of pain, presence of recurrence, and adverse effects were analyzed. A total of 91% of patients responded to treatment, with a median latency of 15 days (interquartile range [IQR], 41). Nine patients (22%) experienced minor recurrence at a median time of 7 months (IQR, 3), and 14 patients (34%) experienced a major recurrence at a median time of 12 months (IQR, 19). After recurrence, both frequency and intensity of episodes remained significantly lower than pretreatment. At last follow-up, response was maintained in 25 patients (60%). No radiosurgery-related severe morbidity or mortality was found. Mask-based immobilization combined with image-guided radiation delivered by rotating gantry-based LINAC system provides a safe and effective radiosurgical treatment for TN, which is indicated for drug-resistant idiopathic or secondary TN patients and for drug-resistant classical TN patients who are not candidates for microvascular decompression.