Infrared navigation system for light dosimetry during pleural photodynamic therapy

Area of Science:

• Oncology
• Medical Physics
• Surgical Technology

Background:

• Pleural photodynamic therapy (PDT) treats microscopic disease in malignant pleural mesothelioma.
• Accurate light dose delivery is essential for PDT efficacy.
• Current methods use discrete detectors, potentially missing areas between locations.

Purpose of the Study:

• To develop and validate an improved method for calculating and monitoring light dose during intraoperative pleural PDT.
• To enhance light fluence uniformity and accuracy within the pleural cavity.
• To assess the real-time applicability of the developed system in surgical settings.

Main Methods:

• An optical infrared (IR) navigation system tracked a modified treatment wand with passive markers.
• Light dose was calculated using a dual correction method with a constant scattered light dose.
• Light fluence uniformity was quantified in 3D and compared to measurements from eight isotropic detectors across seven patient cases.

Main Results:

• The developed method achieved a difference within 15% between calculated and measured light fluence values.
• Light fluence uniformity showed a standard deviation of 10% across the pleural cavity.
• The system accurately determined light dose delivery between detector locations.

Conclusions:

• The optical navigation system and dual correction method improve the accuracy and uniformity of light dose delivery in pleural PDT.
• This approach enhances treatment precision for malignant pleural mesothelioma.
• Real-time implementation in surgery can optimize PDT outcomes.