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Da predição à precisão: aprendizado de máquina e mapeamento dosimétrico para mucosite oral em câncer de cabeça e pescoço

Fri, 09 May 2025 00:00:00 GMT

Título: Da predição à precisão: aprendizado de máquina e mapeamento dosimétrico para mucosite oral em câncer de cabeça e pescoço Autor(es): Fontes, Elisa Kauark Primeiro Orientador: Ramalho, Luciana Maria Pedreira Abstract: Oral mucositis (OM) is a common side effect of head and neck radiotherapy (RT), resulting from a complex interplay of multiple risk factors. Strong evidence identifies RT dose as a key contributor to OM development. A detailed dose-response analysis of individual organs at risk (OARs) may help establish dose constraints to improve patient outcomes. Additionally, machine learning (ML) offers a promising approach by integrating both dosimetric and non-dosimetric factors for a more comprehensive risk assessment. This study aimed to assess OM risk prediction using ML and investigate the impact of dose distribution on OM development, identifying potential OARs related to OM. In the first study, an ML performance was tested to predict MO risk using a cross-validation strategy based on two dataset versions: one with all features and another with feature selection. Comparative analysis showed no relevant results with the full dataset, while feature selection improved performance, with the K-Nearest Neighbors algorithm achieving 64% accuracy, 58% sensitivity, and 68% specificity. The second study involved a dosimetric analysis of 57 head and neck cancer patients. Potential OARs for OM were identified, and dose-volume histograms were generated for OM onset and the final RT session, comparing Dmean and Dmax with OM incidence and distribution. Significant dosimetric differences were observed across all OARs except the upper lip. A Dmean cutoff of 48.4 Gy for the oral tongue was identified (92% accuracy, 96% specificity, 78% sensitivity). Additionally, each incremental 1 Gy increase in dose to the OARs was associated with a 1% higher risk of OM. These findings highlight the need for standardized OAR delineation to optimize RT planning and reduce OM incidence. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese

Aspectos craniofaciais de pessoas com doença falciforme: uma avaliação radiomorfométrica tridimensional

Mon, 15 Jul 2019 00:00:00 GMT

Título: Aspectos craniofaciais de pessoas com doença falciforme: uma avaliação radiomorfométrica tridimensional Autor(es): Barbosa, Inêssa da Silva Primeiro Orientador: Sarmento, Viviane Almeida Abstract: The objective of this research was to perform a three-dimensional assessment of craniofacial features on subjects with sickle cell disease. On this behalf, 70 TC face scans of individuals with diagnosed SCD (test group), attending Dental Sevice at Edgard Santos University Hospital (UFBA, Brazil). Those scans were paired up with clinically normal patients (control group) regarding age and sex, on a 1:1 proportion. All images were assessed using Dolphin Imaging® software version 11.5 Premium (Dolphin Imaging & Management Solutions, Chatsworth, California, EUA) and we performed mandibular and condylar, linear and volumetric, measurements on the 3D module; condyle qualitative assessment on multiplanar reconstructions; evaluation of the skeletal pattern, through linear and angular values, on cephalometric reformations; besides upper airways volume, area and linear measurements. Results showed a very strong intra-examiner agreement (intraclass correlation coefficient of 0,998; p<0,0001) and statistically significant differences for condyle heights (p=0,02), Go-Gn and Cou-Go (p= 0,008 and p< 0,0001, respectively), with differences also for Cop-Gn (p= 0,008) for men while no statisticaly significant differences were found for women. On cephalometric analysis, both SN-GoGn (p= 0,02) and Co-A (p= 0,0011) values were increased whilst the latter kept statistically significant in women (p= 0,001) when evaluation was made according to the patient’s gender. Evaluation of the upper airways showed significant smaller measurements for volume and area (p= 0,007 and p= 0,02 respectively) on test group. One can conclude that these results indicate a tendency of a lower mandibular and condylar growth, especially in men affected with SCD, which, combined with cephalometric finds cope with a vertical growth resultant associated with maxillary protrusion, representing a hyperdivergent Class II skeletal pattern. Upper airways are diminished on SCD subjects, which is in accordance with the presented skeletal pattern. Editora / Evento / Instituição: UNIVERSIDADE FEDERAL DA BAHIA Tipo: Tese

TUMOR DE WHARTIN: UM ESTUDO DE CASOS E DE EXPRESSÃO IMUNO-HISTOQUÍMICA DE MASTÓCITOS

Fri, 09 Apr 2021 00:00:00 GMT

Título: TUMOR DE WHARTIN: UM ESTUDO DE CASOS E DE EXPRESSÃO IMUNO-HISTOQUÍMICA DE MASTÓCITOS Autor(es): Tenório Júnior, Edval Reginaldo Primeiro Orientador: Santos, Jean Nunes dos Abstract: The present study aimed to study, through immunohistochemistry, the participation of mast cells in a Warthin tumor series, as well as to describe their demographic characteristics. The sample consisted of 11 cases of Warthin's tumors. For the evaluation of mast cells, the immunoreactive cells were quantified to the mast cell tryptase markers, in 10 fields (400x). The T test and Pearson's correlation were used for statistical analysis. It was observed in the population, predominance by the male sex (72.7%), 100% location in the parotid gland, the treatment was parotidectomy (100%). The analysis of mast cell expression by statistics (p <0.05), did not reveal a significant difference between mast cells x age (p 0.69) and mast cells x gender (p 0.46). The demographic results of the present study corroborate data found in the literature and point to a possible participation of mast cells in tumor development. Editora / Evento / Instituição: UNIVERSIDADE FEDERAL DA BAHIA Tipo: Dissertação

CONDIÇÃO PERIODONTAL E FATORES RELACIONADOS À DISLIPIDEMIA

Tue, 26 Jul 2022 00:00:00 GMT

Título: CONDIÇÃO PERIODONTAL E FATORES RELACIONADOS À DISLIPIDEMIA Autor(es): SAMPAIO, DAIANE SILVA Primeiro Orientador: SOARES, JOHELLE DE SANTANA PASSOS Abstract: Dyslipidemia is a disorder characterized by increased serum levels of total cholester ol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) and re duced levels of high-density lipoprotein cholesterol (HDL-C). This condition repre sents an important risk factor for cardiovascular diseases and, therefore, should be increasingly investigated. Periodontitis, like other factors, has been associated with lipid alterations. The present study aimed to evaluate the periodontal condition and identify factors related to dyslipidemia. This work was developed in two stages. In the first stage, an umbrella review study was carried out, which synthesized existing me ta-analyses on factors associated with dyslipidemia. Searches were performed on EMBASE, PubMed, Scopus, LILACS, Web of Science and Cochrane Database of Systematic Reviews. In the end, 47 studies were eligible, bringing together 808 pri mary studies, totaling 160 meta-analyses that evaluated 43 factors associated with hyperlipidemia. Only 03 of the 43 factors evaluated showed no association with any of the lipid components. In the second stage, a cross-sectional epidemiological study was carried out in 259 adult individuals treated at Health Units in Salvador, Bahia, to estimate the association between periodontitis and lipid components. For the descrip tive analysis, medians and interquartile ranges were used for continuous variables and frequencies for categorical ones. The Mann-Whitney T test was used in the biva riate analysis and variables with p<0.10 were included in the multinomial regression model. Multivariate analysis showed that TG was the only lipid associated with perio dontitis, when TG > 162mg/dl, and this association was statistically significant (OR=2.97; 95% CI=1.14-1.71). It is concluded that dyslipidemia is a multifactorial disease and is associated with periodontitis, demonstrating the importance of a mul tidisciplinary approach for the control of this lipid disorder. Editora / Evento / Instituição: UNIVERSIDADE FEDERAL DA BAHIA Tipo: Dissertação