Robotic Image-Guided LINAC Radiosurgery for Trigeminal Neuralgia: Results After 10 Years

INTRODUCTION: Frameless image-guided robotic radiosurgery delivering 60 Gy to a 6mm mid-cisternal/retrogasserian segment of the affected trigeminal nerve was used to treat 702 patients affected by severe Trigeminal Neuralgia(TN) refractory to medications . Clinical outcomes in 92 patients with minimum follow-up of 10 years are here reported. METHODS: 702 patients with severe, long-standing TN refractory to medications have been treated at the Cyberknife Center of CDI,Milan,Italy over the last 13 years. A dedicated protocol for imaging ( head CT with and without contrast, slice thickness 0,5 mm; brain MR including MPRAGE and CISS/FIESTA sequences) and treatment( selecting a 6 mm segment of the nerve going from the midcisternal toward the retrogasserian region with a dose prescription of 60Gy @80% isodose) was employed. Regular clinical follow-up was performed one or more times per year according to clinical needs and distance from the treatment. Recurrent pain was treated with the same protocol( a lower dose of 45 Gy was later selected for retreatments). RESULTS: Pain control rates of 92%,87%,76%,74% after respectively 1,2, 3 and 5 years have been found. 92 patients with follow-up longer than 10 years show pain control rate of 72% while the rate of persistent bothering parethesias is 5, 4% (5 patients). No other neurological complications have been found. CONCLUSIONS: Long-term follow-up shows that frameless Linac radiosurgery provides long-term pain control in over 2/3 of the treated patients, with low rate of sensory complications and no other neurological complications.