Targeting accuracy at couch kick for a frameless image guided radiosurgery system

Area of Science:

• Medical Physics
• Radiotherapy
• Image-Guided Therapy

Background:

• Frameless image-guided stereotactic radiosurgery (IGSRS) requires precise targeting.
• Evaluating accuracy across all couch angles is crucial for functional disorder treatments like trigeminal neuralgia.

Purpose of the Study:

• To assess the targeting accuracy of stereoscopic x-ray imaging in IGSRS at various couch angles.
• To validate the feasibility of IGSRS for treating functional disorders using anthropomorphic phantoms.

Main Methods:

• Used anthropomorphic head phantoms with embedded BBs as targets.
• Planned treatment arcs across a range of couch angles (0-270°).
• Measured targeting accuracy using stereoscopic x-ray imaging and phantom positioning.

Main Results:

• Achieved an overall targeting accuracy of 0.5±0.1 mm (range 0.2-0.8 mm).
• Demonstrated consistent accuracy across all tested couch angles.
• No significant correlation between targeting accuracy and couch rotation was observed.

Conclusions:

• Stereoscopic x-ray imaging enables accurate sub-millimeter positioning for IGSRS at any couch angle.
• Frameless IGSRS offers comparable targeting accuracy to frame-based systems for trigeminal neuralgia treatment.