Gamma knife surgery for skull base meningiomas. The effectiveness of low-dose treatment

Surg Neurol. 1999 Jul;52(1):40-4; discussion 44-5. doi: 10.1016/s0090-3019(99)00037-3.


Background: The surgical removal of skull base meningiomas has a high morbidity rate, even by modern microsurgical standards. We evaluated the results of gamma knife surgery for skull base meningiomas using a relatively low radiation dose for the tumor margins.

Methods: We reviewed 24 cases of skull base meningiomas during a 30-month period. The locations of the tumors were the petroclival region in 11 cases, the cavernous sinus region in 9 cases, and the cerebellopontine angle region in 4 cases. Eight patients (33%) had been operated on previously and fourteen patients (67%) had been treated by neuroimaging. The marginal doses for the tumors were 8 Gy to 15 Gy (median, 10.6 Gy). A large petroclival tumor 58 mm in diameter was treated with a staged treatment protocol with a 6-month interval between treatments.

Results: Tumor regression was observed in 46% of the patients imaged during the follow-up period (median, 17.1 months). No patients revealed tumor growth in the follow-up period (100% tumor control rate). Eleven patients (46%) had improved clinically by the time of the follow-up examinations. Preexisting cranial nerve deficit in one patient worsened because of radiation injury.

Conclusion: Although a longer follow-up period is required, the relatively low minimum tumor radiation dose treatment for skull base meningiomas using a gamma knife seems to be an effective treatment with low morbidity.

MeSH terms

  • Adult
  • Aged
  • Cavernous Sinus
  • Cerebellopontine Angle
  • Dose-Response Relationship, Radiation
  • Female
  • Gamma Rays
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Meningeal Neoplasms / pathology
  • Meningeal Neoplasms / physiopathology
  • Meningeal Neoplasms / surgery*
  • Meningioma / pathology
  • Meningioma / physiopathology
  • Meningioma / surgery*
  • Middle Aged
  • Petrous Bone
  • Radiosurgery / instrumentation*
  • Skull Base Neoplasms / pathology
  • Skull Base Neoplasms / physiopathology
  • Skull Base Neoplasms / surgery*
  • Treatment Outcome