Non melanoma skin cancer (NMSC) can be seen as a multifaceted problem, considered primarily as a public health problem whose impact on society considers the morbidity and cost aspects of the treatment. It is a social problem, affecting all those who depend exclusively on the Brazilian public health system and need to wait months to receive any type of treatment. From the economic point of view, to treat all patients diagnosed with NMSC, it is necessary a big investment. Finally, the problem is logistical, since the territorial extension of Brazil and its population distribution do not enable the adequate care in all the places, which requires reallocation of patients from small cities to reference centers. Based on these facts, PDT for small skin lesions may be one of the best solutions from an economic point of view. Being a treatment that is easy for the training of professionals and enables to be performed in an ambulatory environment, minimizing post-treatment effects, this study shows that the cost of implementing the procedure on a large scale is extremely adequate for the national public health service. Using a strategy involving companies, national bank and medical partners, equipment, medication and protocols were tested in a multicenter study. With results collected over 5 years from a national program to implement PDT for non melanoma skin cancer over the Brazilian territory, we could reach a great economic evaluation of advances concerning the use of PDT for skin cancer.
It is estimated that up to 75% of the sexually active population is infected with this human papillomavirus virus (HPV). Condylomas acuminate are benign lesions caused by this virus. This study aims to compare photodynamic therapy (PDT) and administration of 70% trichloroacetic acid (TAA) in the condylomas. Each patient is treated weekly until total removal of the lesions, with one of treatment options. In the patients treated with PDT, a Brazilian 20% methyl aminulevulinate cream were applied in the region and incubated by 3 hours and the lesions were illuminated with the CERCa®. This Brazilian system is composed of LEDs emitting at 630 nm which was initially designed for the treatment of cervical intraepithelial neoplasia (CIN) and this study showed the need to develop new devices for illumination of the anus-genital region. During the illumination, a total dose of 150 J/cm2 is delivered over 21 minutes. 22 patients have participated of this clinical study, totaling 15 patients treated with TAA and 8 with PDT, with a complete treatment for 33% using TAA and 75% for PDT. Besides the results of complete response, it is important to highlight that 2 patients showed recurrence for TAA and 4 patients discontinued the treatment with TAA, while, for PDT, there were no cases both recurrence and withdrawal. Therefore, besides the preliminary results obtained with this project show that PDT has been more effective than TAA, it was possible to plan and develop new equipment to ensure greater range of light.
One of the limiting factors of photodynamic therapy is cutaneous permeation of a photosensitizer or precursor. Studies report that there is a strong relationship between temperature and porphyrin synthesis in biological tissue. The use of thermogenic and/or vasodilator substances may favor both ALA/methyl-ALA permeation and protoporphyrin IX (PpIX) production in the tissue. In this study, menthol, methyl nicotinate, and ginger extract were incorporated into either the ALA or methyl-ALA cream to investigate the PpIX production in rat skin. Fluorescence spectra were collected to quantify the PpIX present in tissues. The methyl nicotinate was the one with the highest optimization effect of PpIX production after three hours of incubation of the cream. Its association with methyl-ALA caused the production to be about 50% higher than that observed for methyl-ALA alone. These results are promising as a possible strategy for decreasing the incubation time of the precursor cream in various clinical protocols and increasing the photosensitizer production in lesions.
The photodynamic therapy (PDT) is a therapeutic modality that depends mostly on photosensitizer (PS), light and molecular oxygen species. However, there are still technical limitations in clinical PDT that are under constant development, particularly concerning PS and light delivery. Intense Pulsed Light (IPL) sources are systems able to generate pulses of high energy with polychromatic light. IPL is a technique mainly used in the cosmetic area to perform various skin treatments for therapeutic and aesthetic applications. The goals of this study were to determine temperature variance during the application of IPL in porcine skin model, and the PDT effects using this light source with PS delivery by a commercial high pressure, needle-free injection system. The PSs tested were Indocyanine Green (ICG) and Photodithazine (PDZ), and the results showed an increase bellow 10 °C in the skin surface using a thermographic camera to measure. In conclusion, our preliminary study demonstrated that IPL associated with needle-free injection PS delivery could be a promising alternative to PDT.
In this study was evaluated the photoaging of patients' skins by the processing of RGB images acquired with an optical system based on a smartphone. Two groups were approached: a younger and an older.
Photodynamic therapy (PDT) is a technique used for several tumor types treatment. Light penetration on biological tissue
is one limiting factor for PDT applied to large tumors. An alternative is using interstitial PDT, in which optical fibers are
inserted into tumors. Cylindrical diffusers have been used in interstitial PDT. Light emission of different diffusers depends
on the manufacturing process, size and optical properties of fibers, which make difficult to establish an adequate light
dosimetry, since usually light profile is not designed for direct tissue-fiber contact. This study discusses the relevance of
light distribution by a cylindrical diffuser into a turbid lipid emulsion solution, and how parts of a single diffuser contribute
to illumination. A 2 cm-long cylindrical diffuser optical fiber was connected to a diode laser (630 nm), and the light spatial
distribution was measured by scanning the solution with a collection probe. From the light field profile generated by a 1
mm-long intermediary element of a 20 mm-long cylindrical diffuser, recovery of light distribution for the entire diffuser
was obtained. PDT was performed in rat healthy liver for a real treatment outcome analysis. By using computational tools,
a typical necrosis profile generated by the irradiation with such a diffuser fiber was reconstructed. The results showed that
it was possible predicting theoretically the shape of a necrosis profile in a healthy, homogeneous tissue with reasonable
accuracy. The ability to predict the necrosis profile obtained from an interstitial illumination by optical diffusers has the
potential improve light dosimetry for interstitial PDT.
Photodynamic therapy (PDT) is a treatment modality that can be indicated for several cancer types and pre-cancer lesions. One of the main applications of PDT is the treatment of superficial skin lesions such as basal cell carcinoma, Bowen’s disease and actinic keratosis. Three elements are necessary in PDT, a photosensitizer (PS); light at specific wavelength to be absorbed by the PS, and molecular oxygen. A typical PS used for skin lesion is protoporphyrin IX (PpIX), which is an intrinsic PS; its production is stimulated by a pro-drug, such as 5-aminolevulinic acid (ALA). Before starting a treatment, it is very important to follow up the PpIX production (to ensure that enough PS was produced prior to a PDT application) and, during a PDT session, to monitor its photodegradation (as it is evidence of the photodynamic effect taking place). The aim of this paper is to present a unique device, LINCE (MMOptics - São Carlos, Brazil), that brings together two probes that can, respectively, allow for fluorescence imaging and work as a light source for PDT treatment. The fluorescence probe of the system is optically based on 400 nm LED (light emitting diodes) arrays that allow observing the fluorescence emission over 450 nm. The PDT illumination probe options are constituted of 630 nm LED arrays for small areas and, for large areas, of both 630 nm and 450 nm LED arrays. Joining both functions at the same device makes PDT treatment simpler, properly monitorable and, hence, more clinically feasible. LINCE has been used in almost 1000 PDT treatments of superficial skin lesions in Brazil, with 88.4% of clearance of superficial BCC.
Onychomycosis is a common disease of the nail plate, constituting approximately half of all cases of nail infection. Onychomycosis diagnosis is challenging because it is hard to distinguish from other diseases of the nail lamina such as psoriasis, lichen ruber or eczematous nails. The existing methods of diagnostics so far consist of clinical and laboratory analysis, such as: Direct Mycological examination and culture, PCR and histopathology with PAS staining. However, they all share certain disadvantages in terms of sensitivity and specificity, time delay, or cost.
This study aimed to evaluate the use of infrared and fluorescence imaging as new non-invasive diagnostic tools in patients with suspected onychomycosis, and compare them with established techniques.
For fluorescence analysis, a Clinical Evince (MM Optics®) was used, which consists of an optical assembly with UV LED light source wavelength 400 nm ± 10 nm and the maximum light intensity: 40 mW/cm2 ± 20%. For infrared analysis, a Fluke® Camera FKL model Ti400 was used. Patients with onychomycosis and control group were analyzed for comparison. The fluorescence images were processed using MATLAB® routines, and infrared images were analyzed using the SmartView® 3.6 software analysis provided by the company Fluke®.
The results demonstrated that both infrared and fluorescence could be complementary to diagnose different types of onychomycosis lesions. The simplicity of operation, quick response and non-invasive assessment of the nail patients in real time, are important factors to be consider for an implementation.
Cancer is responsible for about 13% of all causes of death in the world. Over 7 million people die annually of this disease. In most cases, the survival rates are greater when diagnosed in early stages. It is known that tumor lesions present a different temperature compared with the normal tissues. Some studies have been performed in an attempt to establish new diagnosis methods, targeting this temperature difference. In this study, we aim to investigate the use of a handheld thermographic camera to discriminate skin lesions. The patients presenting Basal Cell Carcinoma, Squamous Cell Carcinoma, Actinic Keratosis, Pigmented Seborrheic Keratosis, Melanoma or Intradermal Nevus lesions have been investigated at the Skin Departament of Amaral Carvalho Hospital. Patients are selected by a dermatologist, and the lesion images are recorded using an infrared camera. The images are evaluated taken into account the temperature level, and differences into lesion areas, borders, and between altered and normal skin. The present results show that thermography may be an important tool for aiding in the clinical diagnostics of superficial skin lesions.
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