title: Predictors of Trigeminal Neuropathy After Radiosurgery for Vestibular Schwannomas.
abstract: To analyze the relationship between dosimetric characteristics and symptoms related to trigeminal neuropathy (TN) observed after radiosurgery (RS) for vestibular schwannomas (VS); to propose guidelines to optimize planification in VS RS regarding TN preservation; and to detail the mechanism of TN impairment after VS RS.
  
  
  
  One hundred seventy-nine patients treated between 2011 and 2013 for VS RS and without trigeminal impairment before RS were included in a retrospective study. Univariate and multivariate analyses were performed to determine predictors of TN among characteristics of the patients, the dosimetry, and the VS.
  
  
  
  There were 20 Koos grade 1, 99 grade 2, 57 grade 3, and 3 grade 4. Fourteen patients (7.8%) presented a transitory or permanent TN. Between the patients with and without TN after VS RS, there was no significant difference regarding dosimetry or VS volume itself. Significant differences (univariate analysis P<.05, Mann-Whitney test) were found for parameters related to the cisternal portion of the trigeminal nerve: total integrated dose, maximum dose, mean dose, volume of the Vth nerve (Volv), and volume of the Vth nerve receiving at least 11 Gy (VolVcist>11Gy), but also for maximal dose to the Vth nerve nucleus and intra-axial portion (Dose maxVax). After multivariate analysis, the best model predicting TN included VolVcist>11Gy (P=.0045), Dose maxVax (P=.0006), and Volv (P=.0058). The negative predictive value of this model was 97%.
  
  
  
  The parameters VolVcist>11Gy, Dose maxVax, and Volv should be checked when designing dosimetry for VS RS.
authors.affiliation: Unité de Radiochirurgie Gamma Knife, Region Ile De France, Paris, France; Service de Neurochirurgie, Centre Hospitalier Universitaire (CHU) La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France; Inserm, U955, Equipe 14, Université Paris Est, Faculté de médecine, Créteil, France.
authors.forename: Suhan
authors.initials: S
authors.lastname: Senova
authors.affiliation: Unité de Radiochirurgie Gamma Knife, Region Ile De France, Paris, France; Service de Neurochirurgie, Centre Hospitalier Universitaire (CHU) La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France.
authors.forename: Mourad
authors.initials: M
authors.lastname: Aggad
authors.affiliation: Service de Biostatistiques, CHU La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Golmard
authors.affiliation: Service de Neuroanatomie, CHU La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Hasboun
authors.affiliation: Unité de Radiochirurgie Gamma Knife, Region Ile De France, Paris, France.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Lamproglou
authors.affiliation: Unité de Radiochirurgie Gamma Knife, Region Ile De France, Paris, France; Service de Radiothérapie, Unité de physique médicale, CHU La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Jenny
authors.affiliation: Service de Neurochirurgie, Centre Hospitalier Universitaire (CHU) La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Cornu
authors.affiliation: Service de Radiothérapie, Unité de physique médicale, CHU La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Mazeron
authors.affiliation: Unité de Radiochirurgie Gamma Knife, Region Ile De France, Paris, France; Service de Neurochirurgie, Centre Hospitalier Universitaire (CHU) La Pitié-Salpêtrière, Assistance Publique des Hôpitaux de Paris, Université Pierre et Marie Curie, Paris, France. Electronic address: charlesambroisevalery@gmail.com.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Valéry
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000532:radiotherapy*; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D020433:Trigeminal Nerve Diseases / Q000209:etiology*