Skip Navigation LinksHome > September 2013 - Volume 73 - Issue 3 > Reduced-Dose Fractionated Stereotactic Radiotherapy for Acou...
Neurosurgery:
doi: 10.1227/NEU.0000000000000019
Research-Human-Clinical Studies

Reduced-Dose Fractionated Stereotactic Radiotherapy for Acoustic Neuromas: Maintenance of Tumor Control With Improved Hearing Preservation

Champ, Colin E. MD*; Shen, Xinglei MD; Shi, Wenyin MD, PhD*; Mayekar, Sonal U.*; Chapman, Katherine*; Werner-Wasik, Maria MD*; Farrell, Christopher J. MD§; Gunn, Vicki*; Downes, M. Beverly MS§; Liu, Haisong PhD*; Evans, James J. MD§; Andrews, David W. MD§

Collapse Box

Abstract

BACKGROUND: Fractionated stereotactic radiotherapy (FSRT) is a noninvasive treatment for acoustic neuromas (ANs). Initial reports from our institution demonstrated that the reduction of treatment dose to 46.8 Gy resulted in improved preservation of functional hearing status.

OBJECTIVE: We now report the tumor control (TC), symptomatic outcome, and hearing preservation (HP) rate in patients treated with reduced-dose FSRT.

METHODS: We analyzed all patients with AN treated from 2002 to 2011. All patients received 46.8 Gy in 1.8-Gy fractions. Follow-up audiogram and magnetic resonance imaging were performed in ≤1-year intervals. TC and HP were calculated by the Kaplan-Meier method. Analysis of HP, defined as Gardner-Robertson value ≤2, was determined by audiometric data. Non-hearing-related symptoms were defined by Common Terminology Criteria for Adverse Events version 4.

RESULTS: In total, 154 patients were analyzed. At a median follow-up of 35 months (range, 4-108), TC was achieved in 96% of patients (n = 148/154) and at 3 and 5 years was 99% and 93%. Eighty-seven patients had serviceable hearing at the time of FSRT and evaluable audiometric follow-up. Overall HP was 67% and at 3 and 5 years was 66% and 54%. Pure tone average decreased by a median of 13 dB in all patients. Nineteen percent (n = 31) of patients experienced symptom improvement, and 8% (n = 13) had worsening of symptoms. Cranial nerve dysfunction occurred in 3.8% of patients (n = 6).

CONCLUSION: Reduced-dose FSRT to 46.8 Gy for AN achieves excellent functional HP rates and limited toxicity without compromising long-term TC. Based on these promising outcomes, further attempts at dose deescalation may be warranted.

ABBREVIATIONS: AN, acoustic neuromas

FSRT, fractionated stereotactic radiotherapy

GR, Gardner-Robertson

HP, hearing preservation

HR, hazard ratio

KM, Kaplan-Meier

PTA, pure tone average

RT, radiation therapy

SD, speech discrimination

SRS, stereotactic radiosurgery

Copyright © by the Congress of Neurological Surgeons

Login

Article Tools

Share

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.