Dedicated Linear Accelerator Radiosurgery for Classic Trigeminal Neuralgia: A Single-Center Experience with Long-Term Follow-Up.

Background: During the past decades, stereotactic radiosurgery, and Gamma Knife in particular, has proved its safety and efficacy for drug-resistant classic trigeminal neuralgia. However, few large series exist using linear accelerator (LINAC) reporting long-term follow-up.

Methods: Between 2006 and 2015, 301 patients were treated by LINAC at our institution. The prescribed radiation dose was 90 Gy at the far anterior target. Clinical response was defined using the Barrow Neurological Institute scale. We considered grades I and IIIa as a successful response. Mean duration of follow-up was 54.6 months (range, 12-132 months).

Results: Two hundred and seventy-three patients (90.7%) were initially pain free, and 28 patients (9.3%) were unchanged. The actuarial probabilities of maintaining pain relief with or without medication (Barrow Neurological Institute grade I and IIIa) at 0.5, 1, 2, 4, 5, and 10 years were 88.7%, 85.0%, 76.1%, 68.8%, 65.8%, and 48.1%, respectively. Hypesthesia was present in only 26.2% of patients (very bothersome, 0.3%). No anesthesia dolorosa was reported. The actuarial probabilities of maintaining pain relief without further surgery at 0.5, 1, 2, 4, and 5 years were 99.3%, 98.3%, 95.8%, 91.0%, and 89.7%, respectively. Among all treated patients, 86.5% were satisfied by the procedure and would undergo stereotactic radiosurgery again.

Conclusions: Stereotactic radiosurgery with dedicated LINAC is associated with high rates of long-term pain relief, with minimal invasiveness and rare complications. LINAC is a possible therapeutic alternative for drug-resistant trigeminal neuralgia and could be proposed to selected patients as the first intention therapy, among other surgical solutions.