An Affordable, Portable Fluorescence Imaging Device for Skin Lesion Detection Using a Dual Wavelength Approach for Image Contrast Enhancement and Aminolaevulinic Acid-induced Protoporphyrin IX. Part II. In Vivo Testing

Abstract

A fluorescence imaging prototype for skin lesion detection and diagnosis using aminolaevulinic acid (ALA) induced protoporphyrin IX (PpIX) was tested in vivo and in the clinic. The prototype was designed as an affordable, portable device to allow contrast enhanced imaging of skin lesions using either the dual excitation wavelength method or the dual emission wavelength method or both. In this study the prototype was tested first on an animal model. Topical application of ALA on defined spots on mouse skin gave PpIX fluorescence after about 3 hours of application. After successful in vivo testing the instrument was tested on basal cell carcinoma patients before ALA-PpIX photodynamic therapy. The patients were topically applied with ALA. After three hours the device was tested (immediately before treatment). The prototype showed good results in terms of contrast enhancement (elimination of unwanted background signals, e.g. autofluorescence) using either contrast enhancement method, both methods achieving similar results. The results achieved in this study, combined with the affordable design of the device, seem to allow cost-effective, contrast-enhanced imaging of skin lesions before or during photodynamic therapy using ALA induced PpIX.

5-Aminolevulinic acid strongly enhances delayed intracellular production of reactive oxygen species (ROS) generated by ionizing irradiation: Quantitative analyses and visualization of intracellular ROS production in glioma cells in vitro

“…5-Aminolevulinic acid (ALA) induces a high accumulation of protoporphyrin IX (PpIX) in tumors, and is widely used in the treatment of various types of cancers (5,6). In the treatment of malignant gliomas, fluorescence-guided surgery using 5-ALA has been useful for determining tumor borders, thereby making the extent of resection easier compared to that in conventional microsurgery (7).…”

Development of Low-Cost Photodynamic Therapy Device

“…Optical Materials, ISCOM07, Belgrade, Serbia, September [3][4][5][6][7]2007 Development of Low-Cost Photodynamic Therapy Device Photodiagnosis and photodynamic therapy of non-melanoma skin cancers using delta-aminolevulinic acid/protoporphyrin IX (5-ALA/PpIX) give a combined application with broadest dissemination in the current clinical practice. The problems with using of lasers as light sources are the expenses associated with the operation of these types of installations.…”

“…Technical characteristics of the "MEDIRAY PDT" apparatus built in the frames of the research project are presented in Table. System parameters completely corresponded to the other commercialized analogues developed for the needs of photodiagnosis and photodynamic therapy in clinical practice [6][7][8].…”

“…Nevertheless that according to existing literature 5-ALA-assisted photodynamic therapy is applied for broad range of benign and malignant dermatological lesions [2][3][4][5][6][7], the main application in the clinical practice is related to the basal cell carcinoma therapy. This skin lesion is the broadest progress of this kind of cutaneous tumor, as well as high-rate of recurrences using standard therapeutic methods.…”

“…Similar systems for diagnostic purposes or therapeutic purposes only are developed based on filtered broad-spectra lamps [3,6,7] or on diode matrices [8]. Main advantage of the system built up is the possibility for simultaneously photodetection and photodynamic treatment of the cutaneous lesion using exogenous 5-ALA/PpIX.…”