title: Linear accelerator stereotactic radiosurgery for vestibular schwannomas: a UK series.
abstract: OBJECTIVE
  To evaluate non-auditory toxicity and local control after linear accelerator stereotactic radiosurgery (SRS) for the treatment of vestibular schwannomas.
  
  
  METHODS
  The institutional policy was to use SRS for radiologically progressing vestibular schwannomas. Case notes and plans were retrospectively reviewed for all patients undergoing SRS for vestibular schwannomas between September 2002 and June 2012. All patients were surgically immobilised using a BrainLab stereotactic head frame. The treatment plan was generated using BrainLab software (BrainScan 5.03). The aim was to deliver 12 Gy to the surface of the target with no margin. Patients with a minimum of 12 months of follow-up were included for toxicity and local control assessment. Radiological progression was defined as growth on imaging beyond 2 years of follow-up. Overall local control was defined in line with other series as absence of surgical salvage.
  
  
  RESULTS
  Ninety-nine patients were identified. Two patients were lost to follow-up. After a median follow-up interval of 2.4 years, the actuarial radiological progression-free survival at 3 years was 100% and overall local control was also 100%. However, two patients progressed radiologically at 3.3 and 4.5 years, respectively. Twenty-one of 97 (22%) evaluable patients suffered trigeminal toxicity and this was persistent in 8/97 (8%). Two of 97 (2%) suffered long-term facial nerve toxicity (one with associated radiological progression causing hemi-facial spasm alone). One of 97 (1%) required intervention for obstructive hydrocephalus. No statistically significant dosimetric relationship could be shown to cause trigeminal or facial nerve toxicity. However, 7/8 patients with persistent trigeminal nerve toxicity had tumours in contact with the trigeminal nerve.
  
  
  CONCLUSIONS
  SRS delivering 12 Gy using a linear accelerator leads to high local control rates, but only prospective evaluation will fully establish short-term toxicity. In this study, persistent trigeminal toxicity occurred almost exclusively in patients whose tumour was in contact with the trigeminal nerve.
authors.affiliation: Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK. Electronic address: paul.sanghera@uhb.nhs.uk.
authors.forename: H
authors.initials: H
authors.lastname: Benghiat
authors.affiliation: Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: G
authors.initials: G
authors.lastname: Heyes
authors.affiliation: Wolfson Computer Laboratory, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: P
authors.initials: P
authors.lastname: Nightingale
authors.affiliation: Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: A
authors.initials: A
authors.lastname: Hartley
authors.affiliation: Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: M
authors.initials: M
authors.lastname: Tiffany
authors.affiliation: Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: D
authors.initials: D
authors.lastname: Spooner
authors.affiliation: Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: J I
authors.initials: JI
authors.lastname: Geh
authors.affiliation: Department of Neurosurgery, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: G
authors.initials: G
authors.lastname: Cruickshank
authors.affiliation: Department of Otolaryngology and Skull Base Surgery, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Irving
authors.affiliation: Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: P
authors.initials: P
authors.lastname: Sanghera
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005154:Facial Nerve / Q000528:radiation effects; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000401:mortality / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D014276:Trigeminal Nerve / Q000528:radiation effects; D006113:United Kingdom; D055815:Young Adult
keywords: Acoustic neuroma; radiosurgery; vestibular schwannoma