SU-E-J-193: Gamma Knife Perfexion End-To-End Testing with a Commercial Stereotactic Phantom.

Area of Science:

• Medical Physics
• Radiosurgery Technology
• Quality Assurance

Background:

• Stereotactic radiosurgery requires rigorous quality assurance for safe and effective treatment delivery.
• The Gamma Knife Perfexion system is a leading technology for precise radiation delivery.
• End-to-end testing protocols are crucial for validating complex treatment systems.

Purpose of the Study:

• To evaluate the Lucy Stereotactic Phantom for quality assurance of the Gamma Knife Perfexion system.
• To assess the phantom's utility in testing imaging, treatment planning, and dose delivery processes.
• To provide a comprehensive end-to-end test for the Gamma Knife Perfexion and Gamma Plan software.

Main Methods:

• The Lucy phantom was imaged using CT and MRI sequences.
• Image fusion accuracy was assessed using fiducial markers.
• Geometric accuracy was evaluated by contouring target volumes.
• Dose delivery was verified using Gafchromic film and analyzed with RIT software.

Main Results:

• T1-weighted MRI sequences provided the most accurate geometric measurements.
• Geometric accuracy for all modalities was within 1.6% in two dimensions.
• Dosimetry results demonstrated good agreement with the planned dose.
• The Gafchromic film calibration showed less than 3% error above 1 Gy.

Conclusions:

• The Lucy phantom is a valuable tool for comprehensive quality assurance of Gamma Knife Perfexion radiosurgery.
• It effectively validates the imaging, planning, and dose delivery stages.
• This study establishes a robust end-to-end testing methodology.