title: CyberKnife radiosurgery as a first treatment for idiopathic trigeminal neuralgia.
abstract: OBJECTIVE
  To report the level of effectiveness and safety, in our experience, of CyberKnife (Accuray, Inc., Sunnyvale, CA) robotic radiosurgery as a first-line treatment against pharmacologically refractory trigeminal neuralgia.
  
  
  METHODS
  We treated 33 patients with the frameless CyberKnife system as a monotherapy. The retrogasserian portion of the trigeminal nerve (a length of 4 mm, 2-3 mm anterior to the root entry zone) was targeted. Doses of 55 to 75 Gy were prescribed to the 100% isodose line, according to a dose escalation protocol. The patients were evaluated for the level of pain control, time to pain relief, hypesthesia, and time to pain recurrence.
  
  
  RESULTS
  The median age was 74 years. All but 2 patients (94%) achieved a successful treatment outcome. The follow-up period was 9 to 37 months (mean, 23 months). The Barrow Neurological Institute Pain Intensity Scale (BPS) score before radiosurgery was III in 2 patients (6%), IV in 8 patients (24%), and V in 23 patients (70%). The time to pain relief was 1 to 180 days (median, 30 days). No facial numbness was observed. Only 1 patient developed a transitory dysesthesia of the tongue. After treatment, the BPS score was I, II, or III in 31 patients (97%). Pain recurred in 33% (11 patients) at a mean of 9 months (range, 1-43 months). Three patients with recurrences had low pain control by medication (BPS score, IV), and 1 patient (BPS score, V) needed a radiofrequency lesioning (BPS score, I at 12 months).
  
  
  CONCLUSIONS
  CyberKnife radiosurgery for trigeminal neuralgia allows pain relief at safe doses and is suggested for pharmacologically refractory trigeminal neuralgia. Higher prescribed doses were not associated with improvement in pain relief or recurrence rate.
authors.affiliation: Division of Radiotherapy, Fondazione Istituto Neurologico C. Besta, and Centro Diagnostico Italiano, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fariselli
authors.forename: Carlo
authors.initials: C
authors.lastname: Marras
authors.forename: Michela
authors.initials: M
authors.lastname: De Santis
authors.forename: Marcello
authors.initials: M
authors.lastname: Marchetti
authors.forename: Ida
authors.initials: I
authors.lastname: Milanesi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Broggi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005157:Facial Pain / Q000209:etiology / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010292:Paresthesia / Q000209:etiology; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D014059:Tongue / Q000528:radiation effects; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000601:surgery*