Metastasis is one of the major cancer complications, since the malignant cells detach from the primary tumor and reaches other organs or tissues. The sentinel lymph node (SLN) is the first lymphatic structure to be affected by the malignant cells, but its location is still a great challenge for the medical team. This occurs due to the fact that the lymph nodes are located between the muscle fibers, making it visualization difficult. Seeking to aid the surgeon in the detection of the SLN, the present study aims to develop a widefield fluorescence imaging device using the indocyanine green as fluorescence marker. The system is basically composed of a 780nm illumination unit, optical components for 810nm fluorescence detection, two CCD cameras, a laptop, and dedicated software. The illumination unit has 16 diode lasers. A dichroic mirror and bandpass filters select and deliver the excitation light to the interrogated tissue, and select and deliver the fluorescence light to the camera. One camera is responsible for the acquisition of visible light and the other one for the acquisition of the ICG fluorescence. The software developed at the LabVIEW<sup>®</sup> platform generates a real time merged image where it is possible to observe the fluorescence spots, related to the lymph nodes, superimposed at the image under white light. The system was tested in a mice model, and a first patient with tongue cancer was imaged. Both results showed the potential use of the presented fluorescence imaging system assembled for sentinel lymph node detection.
One of the limitations of topical photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) is the poor ability to penetrate biological barriers of skin and the recurrence rates in treatments. This study aimed to identify possible signs of increased diffusion of ALA-induced PpIX by fluorescence images and fluorescence spectroscopy. The research was done using <i>in vivo</i> porcine skin model. Before the cream application, microholes was performed with microneedles rollers in only one direction, afterward the ALA cream was applied at a 2.5cm<sup>2</sup> area in triplicate and an occlusive dressing was placed. PpIX production was monitored using fluorescence spectroscopy collected at skin surface after 70, 100, 140, and 180 minutes of ALA incubation. About 100 fluorescence spectra of each treatment were collected, distributed by about five points for each site. Wide-field fluorescence imaging was made after 70, 90, and 170 minutes after treatment. The results obtained by imaging analysis indicated increase of the PpIX diffusion in the skin surface using the microneedles rollers (MNs) before ALA application. Circular regions of red fluorescence around the microholes were observed. In addition, the fluorescence spectra showed a greater intensity (2 times as many) in groups microneedles rollers associated. In conclusion, our data shown greater homogeneity and PpIX production in the groups pre-treated with microneedles indicating that the technique can be used to greater uniformity of PpIX production throughout the area to be treated reducing the chances of recurrent tumor as well as has potential for decreasing the time of therapy. (FUNDING SUPPORT:CAPES, CNPq and FAPESP)
The chemical carcinogens from tobacco are related to over 90% of lung cancers around the world. The
risk of death of this kind of cancer is high because the diagnosis usually is made only in advanced stages.
Therefore, it is necessary to develop new diagnostic methods for detecting the lung cancer in earlier
stages. The Fourier Transform Infrared Spectroscopy (FTIR) can offer high sensibility and accuracy to
detect the minimal chemical changes into the biological sample. The aim of this study is to evaluate the
differences on infrared spectra between normal lung cells and precancerous lung cells transformed by
NNK. Non-cancerous lung cell line e10 (ATCC) and NNK-transformed e10 cell lines were maintained in
complete culture medium (1:1 mixture of Dulbecco's modified Eagle's medium and Ham's F12
[DMEM/Ham's F12], supplemented with 100 ng/ml cholera enterotoxin, 10 lg/ml insulin, 0.5 lg/ml.
hydrocortisol, 20 ng/ml epidermal growth factor, and 5% horse serum. The cultures were maintained in
alcohol 70%. The infrared spectra were acquired on ATR-FTIR Nicolet 6700 spectrophotometer at 4 cm<sup>-1</sup>
resolution, 30 scans, in the 1800-900 cm<sup>-1</sup> spectral range. Each sample had 3 spectra recorded, 30
infrared spectra were obtained from each cell line. The second derivate of spectra indicates that there are
displacement in 1646 cm<sup>-1</sup> (amine I) and 1255 cm<sup>-1</sup>(DNA), allowing the possibility to differentiate the
two king of cells, with accuracy of 89,9%. These preliminary results indicate that ATR-FTIR is useful to
differentiate normal e10 lung cells from precancerous e10 transformed by NNK.