PDT dose dosimetry for pleural photodynamic therapy

Area of Science:

• Biomedical Optics
• Photodynamic Therapy (PDT)

Background:

• Accurate photodynamic therapy (PDT) dosing requires measuring both light fluence and photosensitizer concentration in target tissues.
• Current PDT systems can measure light fluence but lack concurrent photosensitizer measurement capabilities.

Purpose of the Study:

• To develop and validate a novel method for simultaneous real-time measurement of light dosimetry and photosensitizer fluorescence during PDT.
• To enable accurate determination of delivered PDT dose for enhanced treatment efficacy.

Main Methods:

• A new system utilizes an isotropic detector and the treatment light as an excitation source.
• A dichroic beamsplitter directs light to separate dosimetry and fluorescence detection channels.
• Fluorescence signals are normalized by light fluence, and absolute concentrations are determined using optical property corrections and spectral fitting.

Main Results:

• The developed method allows for simultaneous acquisition of light dosimetry and photosensitizer fluorescence data.
• Absolute photosensitizer concentration can be accurately determined in real-time.
• Preliminary patient data demonstrates the feasibility of the technique.

Conclusions:

• This novel method provides accurate, real-time PDT dose determination using existing isotropic detectors.
• The technique has the potential to significantly improve PDT treatment quality compared to current systems.
• Further validation in patient studies is ongoing.