Gamma knife radiosurgery for benign tumor-related trigeminal neuralgia: a single-institution retrospective study.

Background: Gamma knife stereotactic radiosurgery (GKRS) is recognized as an effective and safe alternative treatment for skull base tumors and trigeminal neuralgia. This study aims to evaluate the efficacy of targeting both tumor and trigeminal nerve in a single procedure for patients with benign tumor-related trigeminal neuralgia.

Methods: A retrospective study was conducted on 44 patients with benign tumor-related trigeminal neuralgia who underwent GKRS targeting both tumor and trigeminal nerve in a single procedure between December 2016 and December 2022. The cohort included 30 meningiomas, 9 vestibular schwannomas, and 5 trigeminal schwannomas. The median tumor volume was 3.62 mL (range: 0.14-20.74 mL). The median radiation dose was 12-13.4 Gy for the tumors and 88.9 Gy (range: 85-90 Gy) at the 100% isodose line for the trigeminal nerve. The facial pain before and after GKRS was assessed using the Barrow Neurological Institute (BNI) pain intensity scale.

Results: Following GKRS, 38 patients (86.4%) experienced significant pain improvement, with a median latency period of 2 months (range: 0.3-12 months). Sixteen patients (36.4%) experienced a relapse at a median time of 6 months (range: 1-30 months) post-GKRS. After a median follow-up time of 31.9 months (12.1-77.3 months), 22 patients (50.0%) continued to experience durable pain relief. Fourteen patients (31.8%) developed GKRS-related complications, most of which fully resolved, except in 3 patients (6.8%) who experienced permanent facial hypoesthesia. Tumor control rate was 86.2%.

Conclusions: GKRS targeting both the tumor and trigeminal nerve in a single session demonstrated favorable outcomes in terms of pain relief and tumor control in patients with benign tumor-related trigeminal neuralgia.