Gamma Knife^® icon CBCT offers improved localization workflow for frame-based treatment

Area of Science:

• Neurosurgery
• Medical Imaging
• Radiation Oncology

Background:

• Stereotactic localization is crucial for precise Gamma Knife radiosurgery.
• Traditional fiducial-based localization has limitations.
• Cone beam computed tomography (CBCT) is a newer localization option for Gamma Knife Icon.

Purpose of the Study:

• To compare the accuracy and workflow efficiency of CBCT versus fiducial localization in Gamma Knife treatment planning.
• To determine if a significant difference exists between the two localization methods.
• To identify the more reliable method for stereotactic localization.

Main Methods:

• Utilized Elekta Film Pinprick and anthropomorphic phantoms to assess CBCT accuracy.
• Compared stereotactic coordinates from CBCT and fiducial methods using phantom and patient data.
• Evaluated frameless and frame-based MRI-to-CBCT fusions using the TG-132 TRE method.

Main Results:

• CBCT accurately defines stereotactic space within mechanical system limits.
• CBCT-to-CBCT registration detects offsets within 0.1 mm and 0.5°.
• Disagreements between fiducial and CBCT localization were observed, reaching up to 1.54 mm in patients.

Conclusions:

• CBCT provides consistent and reliable stereotactic localization accuracy.
• CBCT can detect offsets undetectable by fiducial methods, indicating greater reliability.
• CBCT streamlines workflow, offers immediate pre-treatment patient positioning verification, and enhances treatment precision.