Related Experiment Video
Updated: Jun 23, 2026
A Unified Methodological Framework for Vestibular Schwannoma Research
Published on: June 20, 2017
Failure rate of contemporary low-dose radiosurgical technique for vestibular schwannoma
Bruce E Pollock1, Michael J Link, Robert L Foote
1Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA. pollock.bruce@mayo.edu
Object:
The decline in cranial nerve morbidity after radiosurgery for vestibular schwannoma (VS) correlates with dose reduction and other technical changes to this procedure. The effect these changes have had on tumor control has not been well documented.
Methods:
The authors performed a retrospective review of 293 patients with VSs who underwent radiosurgery between 1990 and 2004 and had a minimum of 24 months of imaging follow-up (90% of the entire series). The median radiation dose to the tumor margin was 13 Gy. Treatment failure was defined as progressive tumor enlargement noted on 2 or more imaging studies. The mean postradiosurgical follow-up was 60.9 +/- 32.5 months.
Results:
Tumor growth was noted in 15 patients (5%) at a median of 32 months after radiosurgery. Radiographically demonstrated tumor control was 96% at 3 years and 94% at 7 years after radiosurgery. Univariate analysis revealed 2 factors that correlated with failed radiosurgery for VS: an increasing number of isocenters (p = 0.03) and tumor margin radiation doses
Conclusions:
Distortion of stereotactic MR imaging coupled with increased radiosurgical conformality and progressive dose reduction likely caused some VSs to receive less than the prescribed radiation dose to the entire tumor volume.