Projector-based augmented reality for intuitive intraoperative guidance in image-guided 3D interstitial brachytherapy

Area of Science:

• Medical Imaging and Image-Guided Therapy
• Augmented Reality in Medicine
• Radiation Oncology

Background:

• Interstitial brachytherapy requires precise needle placement for effective radiation delivery.
• Intraoperative orientation can be challenging, impacting surgical accuracy and efficiency.
• Real-time image guidance systems aim to improve surgical outcomes in brachytherapy.

Purpose of the Study:

• To implement an augmented reality (AR) system for real-time image guidance in interstitial brachytherapy.
• To provide intuitive intraoperative orientation for surgeons during brachytherapy procedures.
• To evaluate the accuracy and feasibility of the developed AR system in a clinical setting.

Main Methods:

• A low-cost AR system comprising a video projector, two cameras, and a notebook was developed.
• Coded-light patterns projected by the system registered the patient and superimposed planning data onto the surgical field.
• Stereoscopic tracking of passive markers on the patient detected movements, allowing dynamic adjustment of projected data without rigid fixation.

Main Results:

• The system enabled surgeons to visualize planning data directly on the patient's surface with a clear line of sight.
• The tracking system compensated for patient movement (average deviation 1.1 mm) and projector repositioning (average deviation 0.9 mm).
• Mean deviation for implanted needles was 1.4 mm, demonstrating high accuracy in a clinical study of 10 patients.

Conclusions:

• The developed low-cost augmented reality system is accurate and feasible for interstitial brachytherapy.
• The system provides intuitive real-time intraoperative orientation and monitoring of needle implantation.
• The AR system meets clinical demands for improved image-guided brachytherapy.