title: Long-term outcome after highly advanced single-dose or fractionated radiotherapy in patients with vestibular schwannomas - pooled results from 3 large German centers.
abstract: OBJECTIVE
  To evaluate long-term clinical outcome and determine prognostic factors for local-control, hearing preservation and cranial nerve toxicity in 449 patients treated for 451 vestibular schwannomas (VS) with radiosurgery (n=169; 38%) or fractionated stereotactic radiotherapy (FSRT; n=291; 62%).
  
  
  METHODS
  245 patients were male (55%), and 204 were female (45%). Median age was 60 years (range 17-88 years). Median tumor diameter was 15mm. For FSRT, a median dose of 57.6Gy in median single doses of 1.8Gy was applied. For SRS, median dose was 13Gy. The median follow-up time was 67 months.
  
  
  RESULTS
  Local control was 97% at 36 months, 95% at 60 months, and 94% at 120 months with no difference between FSRT and SRS (p=0.39). "Useful hearing" was present 46%. After RT, "useful hearing" was preserved in 85% of the patients. Loss of useful hearing was observed in the FSRT group in 14%, and in the SRS group in 16% of the patients. For patients treated with SRS ⩽13Gy, useful hearing deterioration was 13%. For trigeminal and facial nerve toxicity, there was no difference between FSRT and SRS.
  
  
  CONCLUSIONS
  Supported by this large multicentric series, both SRS and FSRT can be recommended for the treatment of VS. SRS application is limited by tumor size, and is associated with a steep dose-response-curve. When chosen diligently based on tumor volume, pre-treatment characteristics and volume-dependent dose-prescription in SRS (⩽13Gy), both treatments may be considered equally effective.
authors.affiliation: Department of Radiation Oncology, Technical University of Munich (TUM), Germany. Electronic address: Stephanie.combs@tum.de.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Engelhard
authors.affiliation: Department of Radiation Oncology, Technical University of Munich (TUM), Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Kopp
authors.affiliation: Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85765 Oberschleißheim, Germany; Department of Radiation Oncology, University Hospital of Freiburg, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Wiedenmann
authors.affiliation: Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85765 Oberschleißheim, Germany; Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Schramm
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany; Department of Radiation Oncology, University Hospital of Freiburg, Germany.
authors.forename: Vesna
authors.initials: V
authors.lastname: Prokic
authors.affiliation: Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85765 Oberschleißheim, Germany; Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.affiliation: Department of Radiation Oncology, Technical University of Munich (TUM), Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Molls
authors.affiliation: Department of Radiation Oncology, University Hospital of Heidelberg, Heidelberg, Germany; Department of Radiation Oncology, University Hospital of Freiburg, Germany.
authors.forename: Anca-Ligia
authors.initials: AL
authors.lastname: Grosu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D005154:Facial Nerve; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000503:physiopathology / Q000532:radiotherapy*; D011880:Radiotherapy Planning, Computer-Assisted / Q000009:adverse effects; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
keywords: Acoustic neuroma; Hearing preservation; Local control; Radiation; Radiosurgery