Image-Guided Robotic Radiosurgery for Trigeminal Neuralgia

Neurosurgery. 2018 Nov 1;83(5):1023-1030. doi: 10.1093/neuros/nyx571.


Background: Frameless, non-isocentric irradiation of an extended segment of the trigeminal nerve introduces new concepts in stereotactic radiosurgery for medically resistant trigeminal neuralgia (TN).

Objective: To report the results of the largest single-center experience about image-guided robotic radiosurgery for TN.

Methods: A cohort of 138 patients treated with CyberKnife® (Accuray Incorporated, Sunnyvale, California) radiosurgery with a minimum follow-up of 36 mo were recruited. Pain relief, medications, sensory disturbances, rate and time of pain recurrence were prospectively analyzed.

Results: Median follow-up was 52.4 mo; median dose 75 Gy; median target length 5.7-mm; median target volume 40 mm³; median prescription dose 60 Gy (80% isodose line). Actuarial pain control rate (Barrow Neurological Institute [BNI] class I-IIIa) at 6, 12, 24, and 36 mo were 93.5%, 85.8%, 79.7%, and 76%, respectively. Overall, 33 patients (24%) required a second treatment. Overall, 18.1% developed sensory disturbances after 16.4 ± 8.7 mo. One patient (0.7%) developed BNI grade IV dysfunction; 6 (4.3%) developed BNI grade III (somewhat bothersome) hypoesthesia after retreatment; BNI grade II (not bothersome) hypoesthesia was reported by 18 patients (11 after retreatment). Shorter nerve length (<6 mm vs 6 mm), smaller nerve volume (<30 mm3 vs >30 mm3), and lower prescription dose (<58 vs >58 Gy) were associated with treatment failure (P = .01, P = .02, P = .03, respectively). Re-irradiation independently predicted sensory disturbance (P < .001).

Conclusion: Targeting a 6-mm segment of the trigeminal nerve with a prescribed dose of 60 Gy appears safe and effective. Persistent pain control was achieved in most patients with acceptable risk of sensory complications, which were typically found after re-irradiation.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Middle Aged
  • Radiosurgery / methods*
  • Robotic Surgical Procedures / methods*
  • Treatment Outcome
  • Trigeminal Nerve / surgery
  • Trigeminal Neuralgia / surgery*