Treatment of Acoustic Neuroma: Stereotactic Radiosurgery vs Microsurgery

Diana Stripp, MD
University of Pennsylvania Cancer Center
Last Modified: November 5, 2001

Presenter: Butler, EB
Presenter's Affiliation: Baylor College of Medicine
Type of Session: Scientific


  • Two major treatment options are available for patients with acoustic neuroma, microsurgery and radiosurgery.
  • The objective of this study was to compare these two treatment modalities with respect to tumor growth control, hearing preservation, development of cranial neuropathies, complications, functional outcome and patient satisfaction.

    Materials and Methods

  • 96 patients with unilateral acoustic neuromas treated with Gamma Knife or microsurgery were included in this study.
  • Preoperative patient characteristics were similar except for tumor size and age. Patients undergoing microsurgery were younger with larger tumors compared to the radiosurgical group.
  • The tumors were divided into small < 2.0 cm, medium 2.0 - 3.9 cm or large > 4.0 cm.
  • Median follow-up of the radiosurgical group was longer than the microsurgical group, 48 months vs 24 months.


  • Microsurgery was associated with a greater rate of facial and trigeminal neuropathy(p<0.01).
  • Radiosurgery was more effective in preserving measurable hearing (p=0.01).
  • There was no difference in serviceable hearing preservation between the two groups.
  • Patients had microsurgery stayed longer in hospital and more perioperative complications than patients treated with radiosurgery (p<0.01).
  • There was no difference in the postoperative functioning level, employment and overall patient satisfaction.
  • No correlation between the microsurgical approach used and postoperative side effects.
  • There was no correlation between the radiation dose, tumor size, and number of isocenters used and side effects in the radiosurgical group.
  • There was not a statistically significant difference in tumor growth control between the two groups, 100% in the microsurgery group versus 91% in the radiosurgery group

    Author's Conclusions
    Radiosurgical treatment for acoustic neuroma is an alternative to microsurgery. It is associated with a lower rate of immediate and long-term development of facial and trigeminal neuropathy, postoperative complications and hospital stay. Radiosurgery yields better measurable hearing preservation than microsurgery and equivalent serviceable hearing preservation rate and tumor growth control.

    Clinical/Scientific Implications
    This study shows similar outcomes for hearing preservation with either radiosurgery or microsurgery. However, radiosurgery provides better side effect profile. For small tumors, <2 cm, microsurgery is feasible with low chance of causing permenant neurologic deficits.

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