Applications in Light-induced Spectroscopy with violet LED lamp: autofluorescence

ETCHEVERRY, MARIA EUGENIA; ÁNGEL, PASQUALE MIGUEL; GARAVAGLIA MARIO

Bariloche

Congreso; RAFA2022; 2022

Theearly detection of neoplastic disease, as well as the development ofmore efficient treatments, are crucial for improving the survivalrate. A variety of new and emerging diagnostic strategies based onspectroscopic techniques such as non-invasiveone-point fluorescence (PF) detection,are available to improve the screening procedure [1,2]. PFtechnique provides useful information for monitoring the evolution ofthe abundance and distribution of endogenous fluorophores associatedwith the neoplastic disease in low-pigmented superficial neoplasia[3,4].Themain objective of the present study was to develop a violet LED lightsource suitable for medical application devoted to the diagnostic andtreatment of non-melanoma skin cancers. For this propose, weconstructed a 12 W violet LED lamp (withmaximum emission peak at 405 nm)made up of four mobile 3 W LED, each one coupled to a heat sink and alens and mounted on a platform with adjustable screws. The powersupply allows the modification of the intensity of illumination. TheLED lamp was characterized employing a spectrometer coupled to anoptical fiber. The irradiance for different distances between thelamp and the detector was assessed. Furthermore, the radiant powerand the radiant intensity were evaluated. Data were compared with asimulated LED lamp by using the Zemax optic software for therealization of luminaries with the desired characteristics and modesof operation to deliver the energy density at the interest point, asrequired for medical applications.Thedeveloped lamp in combination with a portable spectrometer wasemployed under medical supervision to detect differences in theemission spectrum of skin suspicious regions and healthy ones locatedat the head of a patient with non-melanoma skin cancer. The light ofthe LED lamp was concentrated in the examined region by means of theproper focusing of the four individual LEDs, rendering a highintensity homogeneous spot. Thus, endogenous chromophores at the skinwere excited, and the emission intensity appeared to be enough todetect an enhanced peaked structure around 600 nm for some suspiciousregions before treatment, and that were absence in healthy regions.These differences can be related to the augmented protoporphyrin IXcontent in neoplastic regions. Resultspresented in this work indicates the usefulness of the developed andcharacterized LED lamp as an easy-to-use device for the non-invasivedetection of skin neoplastic pathologies, before and after treatment,with the aim of better define the malignant regions as well aspredict the outcome of a certain treatment. p { margin-bottom: 0.11cm; direction: ltr; color: #00000a; text-align: justify; orphans: 2; widows: 2 }p.western { font-family: "Times New Roman", serif; font-size: 10pt; so-language: es-ES }p.cjk { font-family: "Times New Roman"; font-size: 10pt; so-language: es-ES }p.ctl { font-family: "Times New Roman"; font-size: 10pt; so-language: ar-SA }a:link { color: #0000ff }