Performance characterization of an integrated cone-beam CT system for dedicated gamma radiosurgery

Area of Science:

• Medical Physics
• Radiosurgery Technology
• Imaging Systems

Background:

• The Gamma Knife Icon is an advanced radiosurgery platform utilizing cone-beam computed tomography (CBCT) for image guidance.
• Accurate performance characterization is crucial for ensuring patient safety and treatment efficacy in radiosurgery.

Purpose of the Study:

• To comprehensively evaluate the performance of the cone-beam CT-guided Gamma Knife Icon radiosurgery device.
• To assess various aspects including image quality, mechanical stability, and treatment delivery accuracy.

Main Methods:

• Performance testing encompassed image quality, mechanical integrity, image coregistration, adaptive treatment delivery, and CBCT software communication.
• Specific evaluations included detector tilt angle, stereotactic space accuracy, motion management precision, and daily setup coregistration.
• End-to-end testing quantified overall system uncertainty in positioning and dosimetry.

Main Results:

• Image quality and mechanical stability met or exceeded manufacturer specifications over a 3-month period.
• CBCT stereotactic space definition showed minimal discrepancy (0.15-0.16 mm).
• High-definition motion management achieved sub-millimeter accuracy, and adaptive treatment delivery was accurate to within 0.2°, with total uncertainty <0.2 mm positioning and 0.4% dosimetry.

Conclusions:

• The presented performance characterization tests cover all critical aspects of the Gamma Knife Icon system.
• Overall system performance aligns with manufacturer specifications, validating its suitability for advanced radiosurgery.