Results of Multiple Gamma Knife Radiosurgery Treatments for Recurrent Trigeminal Neuralgia. (16th November 2020) - Gupta, Mihir
Abstract: INTRODUCTION: Gamma Knife radiosurgery (GKRS) is an established surgical option for treatment of trigeminal neuralgia (TN), particularly for high-risk surgical candidates and those with recurrent pain. However, outcomes after three or more GKRS treatments have rarely been reported. METHODS: We conducted a multi-center retrospective analysis of patients who underwent at least three GKRS treatments for TN between July 1997 and April 2019. Clinical characteristics, radiosurgical dosimetry and technique, pain outcomes, and complications were reviewed. Pain outcomes were scored on the Barrow Neurological Institute (BNI) scale, including time to pain relief (BNI score III or less) and recurrence (BNI > III). RESULTS: A total of 30 patients were identified, including 16 women (53%) and 14 men (47%). Median pain duration prior to the first GKRS treatment was 10 years (range 0.5-28 years). Median age at the first treatment was 69 years (range 42–86), and 77 years at the third treatment (range 47–94). Three patients (10%) had multiple sclerosis. Times to pain relief were similar between the three treatments ( P = .7406). Median times to recurrence were 25, 20, and 18 months for the first, second and third treatments, respectively; differences did not reach significance. Overall complication rates were also similar following each treatment. New or worsened facial sensory dysfunction following the third treatment occurred in 8 patients (29%), including numbness/paresthesias (n = 7) and pain (n = 1). One year after the third treatment, 87% of patients maintained pain relief without additional procedures. At the most recent follow-up (median 39 months from the third treatment; range 0–108 months), 23 patients (77%) reported sustained pain relief. Three patients underwent a fourth GKRS treatment, including one who also received five treatments; all reported sustained pain relief at extended follow-up. CONCLUSION: We describe the largest series to date of patients undergoing three or more GKRS treatments for refractory TN. A third treatment may produce similar outcomes as the first two treatments with respect to long-term pain relief, recurrence and adverse effects. Further investigation is warranted to establish outcome benchmarks and guide patient selection.