title: Does increased nerve length within the treatment volume improve trigeminal neuralgia radiosurgery? A prospective double-blind, randomized study.
abstract: OBJECTIVE
  To test the hypothesis that increasing the nerve length within the treatment volume for trigeminal neuralgia radiosurgery would improve pain relief.
  
  
  METHODS
  Eighty-seven patients with typical trigeminal neuralgia were randomized to undergo retrogasserian gamma knife radiosurgery (75 Gy maximal dose with 4-mm diameter collimators) using either one (n = 44) or two (n = 43) isocenters. The median follow-up was 26 months (range 1-36).
  
  
  RESULTS
  Pain relief was complete in 57 patients (45 without medication and 12 with low-dose medication), partial in 15, and minimal in another 15 patients. The actuarial rate of obtaining complete pain relief (with or without medication) was 67.7% +/- 5.1%. The pain relief was identical for one- and two-isocenter radiosurgery. Pain relapsed in 30 of 72 responding patients. Facial numbness and mild and severe paresthesias developed in 8, 5, and 1 two-isocenter patients vs. 3, 4, and 0 one-isocenter patients, respectively (p = 0.23). Improved pain relief correlated with younger age (p = 0.025) and fewer prior procedures (p = 0.039) and complications (numbness or paresthesias) correlated with the nerve length irradiated (p = 0.018).
  
  
  CONCLUSIONS
  Increasing the treatment volume to include a longer nerve length for trigeminal neuralgia radiosurgery does not significantly improve pain relief but may increase complications.
authors.affiliation: Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. jflickin@msx.upmc.edu
authors.forename: J C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: B E
authors.initials: BE
authors.lastname: Pollock
authors.forename: D
authors.initials: D
authors.lastname: Kondziolka
authors.forename: L K
authors.initials: LK
authors.lastname: Phuong
authors.forename: R L
authors.initials: RL
authors.lastname: Foote
authors.forename: S L
authors.initials: SL
authors.lastname: Stafford
authors.forename: L D
authors.initials: LD
authors.lastname: Lunsford
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016634:Radiosurgery / Q000379:methods*; D014276:Trigeminal Nerve / Q000473:pathology / Q000601:surgery*; D014277:Trigeminal Neuralgia / Q000473:pathology / Q000601:surgery*