Share Email Print
cover

Proceedings Paper

Multi-spectral wide-field imaging for PplX PDT dosimetry of skin (Conference Presentation)
Author(s): Ethan LaRochelle; Hayden H. Chun; Tayyaba Hasan; Brian W. Pogue; Edward V. Maytin M.D.; Michael S. Chapman M.D.; Scott C. Davis

Paper Abstract

Actinic Kertoses (AK) are common pre-cancerous lesions associated with sun-damaged skin. While generally benign, the condition can progress to squamous cell carcinoma (SCC) and is a particular concern for immunosuppressed patients who are susceptible to uncontrolled AK and SCC. Among the FDA-approved treatment options for AK, ALA-based photodynamic therapy is unique in that it is non-scarring and can be repeated on the same area. However, response rates vary widely due to variations in drug and light delivery, PpIX production, and tissue oxygenation. Thus, developing modalities to predict response is critical to enable patient-specific treatment-enhancing interventions. To that end, we have developed a wide-field spectrally-resolved fluorescence imaging system capable of red and blue light excitation. While blue light excites PpIX efficiently, poor photon penetration limits the image content to superficial layers of skin. Red light excitation, on the other hand, can reveal fluorescence information originating from deeper in tissue, which may provide relevant information about PpIX distribution. Our instrument illuminates the skin via a fiber-based ring illuminator, into which is coupled sequentially a white light source, and blue and red laser diodes. Light emitted from the tissue passes through a high-speed filter wheel with filters selected to resolve the PpIX emission spectrum. This configuration enables the use of spectral fitting to decouple PpIX fluorescence from background signal, improving sensitivity to low concentrations of PpIX. Images of tissue-simulating phantoms and animal models confirm a linear response to PpIX, and the ability to image sub-surface PpIX inaccessible with blue light using red excitation.

Paper Details

Date Published: 26 April 2016
PDF: 1 pages
Proc. SPIE 9694, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXV, 96940N (26 April 2016); doi: 10.1117/12.2213463
Show Author Affiliations
Ethan LaRochelle, Thayer School of Engineering at Dartmouth (United States)
Hayden H. Chun, Thayer School of Engineering at Dartmouth (United States)
Tayyaba Hasan, Wellman Ctr. for Photomedicine (United States)
Brian W. Pogue, Thayer School of Engineering at Dartmouth (United States)
Edward V. Maytin M.D., Cleveland Clinic Lerner Research Institute (United States)
Michael S. Chapman M.D., Dartmouth Hitchcock Medical Ctr. (United States)
Scott C. Davis, Thayer School of Engineering at Dartmouth (United States)


Published in SPIE Proceedings Vol. 9694:
Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XXV
David H. Kessel; Tayyaba Hasan, Editor(s)

© SPIE. Terms of Use
Back to Top