Trigeminal Neuralgia Treated With Stereotactic Radiosurgery: The Effect of Dose Escalation on Pain Control and Treatment Outcomes

Int J Radiat Oncol Biol Phys. 2016 Sep 1;96(1):142-8. doi: 10.1016/j.ijrobp.2016.04.013. Epub 2016 Apr 20.


Purpose: To analyze the effect of dose escalation on treatment outcome in patients undergoing stereotactic radiosurgery (SRS) for trigeminal neuralgia (TN).

Methods and materials: A retrospective review was performed of 870 patients who underwent SRS for a diagnosis of TN from 2 institutions. Patients were typically treated using a single 4-mm isocenter placed at the trigeminal nerve dorsal root entry zone. Patients were divided into groups based on treatment doses: ≤82 Gy (352 patients), 83 to 86 Gy (85 patients), and ≥90 Gy (433 patients). Pain response was classified using a categorical scoring system, with fair or poor pain control representing treatment failure. Treatment-related facial numbness was classified using the Barrow Neurological Institute scale. Log-rank tests were performed to test differences in time to pain failure or development of facial numbness for patients treated with different doses.

Results: Median age at first pain onset was 63 years, median age at time of SRS was 71 years, and median follow-up was 36.5 months from the time of SRS. A majority of patients (827, 95%) were clinically diagnosed with typical TN. The 4-year rate of excellent to good pain relief was 87% (95% confidence interval 84%-90%). The 4-year rate of pain response was 79%, 82%, and 92% in patients treated to ≤82 Gy, 83 to 86 Gy, and ≥90 Gy, respectively. Patients treated to doses ≤82 Gy had an increased risk of pain failure after SRS, compared with patients treated to ≥90 Gy (hazard ratio 2.0, P=.0007). Rates of treatment-related facial numbness were similar among patients treated to doses ≥83 Gy. Nine patients (1%) were diagnosed with anesthesia dolorosa.

Conclusions: Dose escalation for TN to doses >82 Gy is associated with an improvement in response to treatment and duration of pain relief. Patients treated at these doses, however, should be counseled about the increased risk of treatment-related facial numbness.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Causality
  • Child
  • Comorbidity
  • Dose-Response Relationship, Drug
  • Facial Pain / diagnosis
  • Facial Pain / epidemiology*
  • Facial Pain / prevention & control*
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Michigan / epidemiology
  • Middle Aged
  • Ohio / epidemiology
  • Pain Measurement / radiation effects
  • Pain Measurement / statistics & numerical data*
  • Prevalence
  • Radiation Dose Hypofractionation
  • Radiosurgery / methods
  • Radiosurgery / statistics & numerical data*
  • Retrospective Studies
  • Risk Factors
  • Treatment Outcome
  • Trigeminal Neuralgia / diagnosis
  • Trigeminal Neuralgia / epidemiology*
  • Trigeminal Neuralgia / radiotherapy*
  • Young Adult