Approaches to needle navigation in interstitial brachytherapy using infrared tracking and radiography

Area of Science:

• Medical Physics
• Radiotherapy
• Surgical Navigation

Background:

• Intraoperative cone-beam computed tomography (CBCT) aids gynecologic brachytherapy applicator positioning but increases radiation exposure and procedure time due to repeated imaging.
• Accurate 3D applicator positioning is crucial for effective brachytherapy treatment delivery.

Purpose of the Study:

• To develop and evaluate methods for intraoperative needle path navigation and correction, reducing the need for multiple CBCT scans.
• To enable accurate, real-time needle guidance by combining infrared tracking with planar X-ray imaging.

Main Methods:

• Real-time tracking of a brachytherapy needle using an infrared-reflective tool.
• 3D needle tip localization via backprojection from two planar X-ray images, reconstructing the needle path with splines.
• A secondary method utilizing one planar X-ray image and prior CBCT bending information for needle prediction.

Main Results:

• The two-X-ray-image method achieved needle path reconstruction with <1 mm deviation from CBCT reference scans.
• The single-scan approach with prior bending data showed promising results with <1.3 mm tip deviation.
• Both methods were validated against CBCT ground-truth in preclinical studies.

Conclusions:

• The developed needle navigation methods are feasible for preclinical applications.
• These techniques show potential to enhance and expedite clinical brachytherapy implantation workflows.
• Improved needle guidance can lead to more efficient and safer radiotherapy procedures.