Emerging Indications for Fractionated Gamma Knife Radiosurgery

Area of Science:

• Neurosurgery
• Radiation Oncology
• Medical Physics

Background:

• Gamma Knife radiosurgery (GKRS) offers precise intracranial tumor treatment.
• Single-session GKRS is contraindicated for certain large or sensitive tumors.
• Traditional pin-based head frames prevent fractionated GKRS.

Purpose of the Study:

• To evaluate fractionated GKRS with a relocatable, noninvasive immobilization system.
• To assess outcomes for specific patient indications treated with fractionated GKRS.

Main Methods:

• Utilized the Extend system for noninvasive immobilization in fractionated GKRS.
• Included patients with large benign tumors (>10 cc), perioptic tumors, vestibular schwannomas (hearing preservation), or reirradiation cases.
• Treated 37 tumors across various types including meningiomas, pituitary adenomas, and brain metastases.

Main Results:

• Fractionated GKRS was applied to 34 patients (37 tumors).
• All patients with perioptic tumors maintained or improved vision.
• All vestibular schwannoma patients preserved serviceable hearing.
• No severe adverse events were reported.

Conclusions:

• Fractionated GKRS is well-tolerated for large meningiomas and perioptic tumors.
• It is effective for vestibular schwannomas with hearing preservation intent.
• Fractionated GKRS is a viable option for reirradiation of previously treated tumors.