Fluorescence spectroscopy for detection of premalignant lesions and squamous cell carcinoma of the oral cavity: prospective study

Author(s)

Ana Lucia Noronha Francisco

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2011-02-25

Examining board members

Luiz Paulo Kowalski; Cristina Kurachi; Márcio Ajudarte Lopes

• Advisor: Luiz Paulo Kowalski

Abstract

Oral cancer is a public health problem with high incidence in the Brazilian population. The affected patient usually presents for clinical investigation, with advanced stage disease, the consequence of this delay is a reduction in survival rates. Given this, it's essential to detect oral cancer in early stages. Fluorescence spectroscopy is a non-invasive diagnostic tool that can aid in cancer detection in real time, with the potential to provide similar sensitivity and specificity for clinical diagnosis of experienced professionals. This technique is relatively simple, fast and accurate which evaluates the biochemical composition and structure of the tissue fluorescence spectrum emitted by it, after application of a light source. When there is a progression from normal state to an altered state, this is reflected in the spectral characteristics of fluorescence of tissues, which may be correlated with the histopathological examination of tissues. The aim of this study was to discriminate, in the oral mucosa, healthy tissue and tumor, through fluorescence spectroscopy. Assessments occurred in patients of the Department of Head and Neck Surgery and Otorhinolaryngology, Hospital A. C. Camargo and the Special Laboratory of Laser in Dentistry, USP, São Paulo, Brazil. The study was approved by the Ethics Research Committee of the participant institutions. The sample consisted of 150 individuals who were submitted to fluorescence spectroscopy, of whom 55 patients had oral carcinoma, 30 volunteers with normal oral mucosa, 35 patients without oral lesions, but with a previous history of malignancy, who underwent surgery or surgery and radiotherapy, and 30 patients with a clinically detectable potentially malignant lesions. 81 cases (54%) were male and the mean age was of 62.7 years. Regarding risk factors, 76 (50.6%) were smokers and 31 (20.7%) consumed alcohol. Biopsies were performed and the results of these two methods were compared using the histopathologic diagnosis as the gold standard for comparison to the spectral characteristics of each type of lesion. The spectra were classified and compared to histopathology for determining the efficiency in diagnostic discrimination employing fluorescence. The analysis consisted of various types of mathematical processing of spectra, and the accuracies Bayes 0,513 and 0,618 and J48 0,829 and 0,887 in lengths of 532 and 406nm, respectively. It can be observed variability among diseases, among the anatomical sites among individuals and among regions of the same injury. The specificity and sensitivity of the technique varies depending on the type of analysis employed as the excitation at 406 nm the algorithm J48 + CFS showed sensitivity of 88,5% and specificity of 93,8% and may in some cases, one can see its potential use as an aid to diagnosis of oral cancer (AU)

• FAPESP's process: 09/12938-8 - Fluorescence spectroscopy for the detection of malignant oral lesions
• Grantee: Ana Lucia Noronha Francisco
• Support Opportunities: Scholarships in Brazil - Master