Emerging Indications for Fractionated Gamma Knife Radiosurgery

Neurosurgery. 2017 Feb 1;80(2):210-216. doi: 10.1227/NEU.0000000000001227.


Background: Gamma Knife radiosurgery (GKRS) allows for the treatment of intracranial tumors with a high degree of dose conformality and precision. There are, however, certain situations wherein the dose conformality of GKRS is desired, but single session treatment is contraindicated. In these situations, a traditional pin-based GKRS head frame cannot be used, as it precludes fractionated treatment.

Objective: To report our experience in treating patients with fractionated GKRS using a relocatable, noninvasive immobilization system.

Methods: Patients were considered candidates for fractionated GKRS if they had one or more of the following indications: a benign tumor >10 cc in volume or abutting the optic pathway, a vestibular schwannoma with the intent of hearing preservation, or a tumor previously irradiated with single fraction GKRS. The immobilization device used for all patients was the Extend system (Leksell Gamma Knife Perfexion, Elekta, Kungstensgatan, Stockholm).

Results: We identified 34 patients treated with fractionated GKRS between August 2013 and February 2015. There were a total of 37 tumors treated including 15 meningiomas, 11 pituitary adenomas, 6 brain metastases, 4 vestibular schwannomas, and 1 hemangioma. At last follow-up, all 21 patients treated for perioptic tumors had stable or improved vision and all 4 patients treated for vestibular schwannoma maintained serviceable hearing. No severe adverse events were reported.

Conclusion: Fractionated GKRS was well-tolerated in the treatment of large meningiomas, perioptic tumors, vestibular schwannomas with intent of hearing preservation, and in reirradiation of previously treated tumors.

Keywords: Gamma Knife radiosurgery; Meningioma; Pituitary adenoma; Radiosurgery; Vestibular schwannoma.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Databases, Factual
  • Female
  • Follow-Up Studies
  • Hearing Tests
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Nervous System Neoplasms / surgery*
  • Radiosurgery / adverse effects
  • Radiosurgery / methods*
  • Retrospective Studies
  • Treatment Outcome