title: Long-term follow-up reveals low toxicity of radiosurgery for vestibular schwannoma.
abstract: OBJECTIVE
  The long-term effects of radiosurgery of vestibular schwannomas were investigated in a group of consecutively treated patients.
  
  
  METHODS
  Between 1995 and 2001, 26 patients (median age: 67, range: 30-82) with a vestibular schwannoma were treated by Linac-based stereotactic radiosurgery (SRS). The median follow-up was 49 months (16-85 months). Only progressive tumours were treated. The median size of tumours was 18 mm (range 9-30 mm). Before SRS, 11 patients had a useful hearing (Gardner-Robertson classes 1 and 2). Single doses of 10-14 Gy were prescribed at the 80% isodose at the tumour margin. The follow-up consisted of regular imaging with MRI the first 3-6 months after the intervention, followed by additional yearly MRIs, a hearing test and a neurological examination.
  
  
  RESULTS
  The 5-year-probability of tumour control (defined as stabilization or decrease in size) was 95%. Five-year-probability of preservation of hearing and facial nerve function was 96% and 100%, respectively. Hearing was preserved in 10 out of 11 patients who had a normal or useful hearing at the time of treatment. Mild and transient trigeminal toxicity occurred in 2 (8%) patients. It appeared to be significantly correlated to the dose used (p=0.044). However, only a tendency to significance could be demonstrated in the relationship between the two factors when using the Cox analysis (hazard ratio=1.7; 95% CI: 0.7-3.9; p=0.23).
  
  
  CONCLUSIONS
  With the doses used, our study demonstrates that SRS provides an equivalent tumour control rate when compared to surgery, as well as on a long-term basis, an excellent preservation of the facial and the acoustic nerves. Although no permanent trigeminal toxicity was observed, our data confirm that doses below 14 Gy can avoid transient dysesthesias.
authors.affiliation: Department of Radiotherapy, C.H.U. of Liège, Liège, Belgium. irutten@chu.ulg.ac.be
authors.forename: Isabelle
authors.initials: I
authors.lastname: Rutten
authors.forename: Brigitta G
authors.initials: BG
authors.lastname: Baumert
authors.forename: Laurence
authors.initials: L
authors.lastname: Seidel
authors.forename: Snezana
authors.initials: S
authors.lastname: Kotolenko
authors.forename: Jacques
authors.initials: J
authors.lastname: Collignon
authors.forename: Bruno
authors.initials: B
authors.lastname: Kaschten
authors.forename: Adelin
authors.initials: A
authors.lastname: Albert
authors.forename: Didier
authors.initials: D
authors.lastname: Martin
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Deneufbourg
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Demanez
authors.forename: Achille
authors.initials: A
authors.lastname: Stevenaert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003391:Cranial Nerves / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D016896:Treatment Outcome