Tumor-targeted Gamma Knife radiosurgery in patients with trigeminal neuralgia secondary to benign tumors.

Background: Secondary trigeminal neuralgia (TN) is often associated with benign meningiomas and schwannomas. For patients who are unable to undergo surgical resection, Gamma Knife radiosurgery (GKRS) is a well-established alternative for tumor control. There is limited data on the pain outcomes in these patients undergoing tumor-targeted GKRS.

Methods: Patients receiving tumor-targeted GKRS for a benign tumor causing secondary TN between 2005 and 2021 were identified. The Barrow Neurological Institute (BNI) pain score was documented at baseline and over the course of clinical follow-up. The study endpoint was defined as either last documented follow-up or date of additional pain procedure.

Results: Seventeen patients were identified with 12 meningiomas (71%), 4 vestibular schwannomas (24%), and 1 trigeminal schwannoma (6%). Patients received either a single fraction of 12-13 Gy in 14 patients (82%) or 25 Gy in 5 fractions for 3 patients (18%). At a mean time to study endpoint of 29.5 months, 6 patients (35%) were pain free. Median time to BNI pain improvement was 4.6 months post-GKRS. One patient (6%) experienced new onset facial numbness. After the study endpoint, five patients (29%) underwent at least one subsequent balloon compression procedure for pain control. Mean total follow-up time was 61.9 months.

Conclusion: For patients with secondary TN due to benign lesions who are poor candidates for surgical resection, tumor-targeted GKRS has a modest effect on pain outcomes. Complication rates are also comparatively very low.