title: Impact of target location on the response of trigeminal neuralgia to stereotactic radiosurgery.
abstract: OBJECTIVE
  The authors evaluate the impact of target location on the rate of pain relief (PR) in patients with intractable trigeminal neuralgia (TN) undergoing stereotactic radiosurgery (SRS).
  
  
  METHODS
  The authors conducted a retrospective review of 99 patients with idiopathic TN who were identified from a prospectively maintained database and were treated with SRS targeting the dorsal root entry zone with a maximum dose of 80 Gy. Targeting of the more proximal portion of a trigeminal nerve with the 50% isodose line overlapping the brainstem was performed in 36 patients (proximal group). In a matched group, 63 patients received SRS targeting the 20% isodose line tangential to the emergence of the brainstem (distal group). The median follow-up time was 33 months (range 6-124 months).
  
  
  RESULTS
  The actuarial rate of maintenance of Barrow Neurological Institute (BNI) Pain Score I-IIIa was attained in 89% of patients at 1 year, 81% at 2 years, and 69% at 4 years, respectively, after SRS. Kaplan-Meier analysis revealed that durability of PR was only associated with the proximal location of the radiosurgical target (log-rank test, p = 0.018). Radiosurgery-induced facial numbness (BNI Score II or III) developed in 35 patients, which was significantly more frequent in the proximal group (19 patients [53%] compared with 16 [25%] in the distal group [p = 0.015]).
  
  
  CONCLUSIONS
  The radiosurgical target appears to affect the duration of pain relief in patients with idiopathic trigeminal neuralgia with the target closer to the brainstem affording extended pain relief. However, the proximal SRS target was also associated with an increased risk of mild to moderate facial numbness.
authors: Departments of Neurosurgery and.
authors: Zhiyuan
authors: Z
authors: Xu
authors: David
authors: D
authors: Schlesinger
authors: Krisztina
authors: K
authors: Moldovan
authors: Colin
authors: C
authors: Przybylowski
authors: Xingwen
authors: X
authors: Sun
authors: Cheng-Chia
authors: CC
authors: Lee
authors: Chun-Po
authors: CP
authors: Yen
authors: Jason
authors: J
authors: Sheehan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006987:Hypesthesia / Q000453:epidemiology / Q000209:etiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000453:epidemiology / Q000601:surgery*