Avaliação multiparamétrica de tumores da próstata por ressonância magnética: espectroscopia e difusão
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2014
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Actualmente, a biópsia por Ecografia é o meio mais utilizado na detecção do Adenocarcinoma da Próstata (AdP).
Contudo, a sensibilidade da técnica na localização é baixa (39 % - 52 %). Pretende-se avaliar a capacidade das técnicas de Espectroscopia por Ressonância Magnética (MRS) e Imagem ponderada em Difusão (DWI) na detecção e localização de lesões prostáticas .
Estudou-se uma amostra de 18 doentes do sexo masculino com idade média de 68.2 anos, submetidos a biópsia prostática. 11 doentes apresentaram diagnóstico de AdP com Gleason Score (GS) de 7, 4 apresentaram prostatite crónica e 3 apresentaram resultado histológico negativo. Utilizaram-se as técnicas de MRS e DWI para estudar lesões prostáticas, e os parênquimas das zonas central e periférica saudável da glândula. Mediram-se os valores de rácio colina/citrato (Cho/
Ci) e do coeficiente de difusão aparente (ADC). Foi aplicada estatística descritiva e comparativa.
Nos doentes com AdP, observaram-se diferenças entre os valores médios de Cho/Ci (p=0,000) e ADC (p=0,000) das
lesões e das zonas periféricas de parênquima saudável. Nos doentes com histologia negativa, observou-se diferenças
entre os valores médios de Cho/Ci na lesão e o parênquima saudável (p=0,006). O valor Cho/Ci da lesão correlacionou-se positivamente com o GS (rS=0,677; p=0,045). Os resultados mostram que as técnicas MRS e DWI permitem identificar e localizar lesões tumorais e suspeitas, tendo assim potencial para orientar a biópsia no estudo do AdP.
Currently, ultrasonography-guided biopsy is the most widely used method in the detection of prostate cancer (PCa). However, the sensitivity of the technique is low (39 % - 52 %). In this work, Magnetic Resonance Spectroscopy (MRS) and Diffusion-Weighted Imaging (DWI) will be studied regarding their ability to detect and localize prostatic lesions. Eighteen male patients, who underwent prostate biopsy were studied. A total of 11 patients were diagnosed with PCa, with a modal Gleason Score (GS) of 7; 4 had chronic prostatitis and 3 had negative histological results. Spectroscopy and diffusion by MRI were used to study prostate lesions, and the parenchyma of the central and healthy peripheral zones of the gland. Values of choline/citrate (Cho/Ci) and Apparent Diffusion Coefficient (ADC) were measured. Descriptive and comparative statistics were applied. In patients with PCa, differences were observed between the mean values of Cho/Ci (p=0,000) and ADC (p=0,000) in lesions and healthy peripheral parenchyma. In patients with negative histology, there were differences observed between the mean values of Cho/Ci in suspected lesions and healthy peripheral parenchyma (p=0,006). The Cho/Ci of lesions was positively correlated with GS (rS=0,677; p=0,045). Results show that MRS and DWI are able to identify and locate tumor lesions and suspected areas, thus having the potential to guide biopsy in the study of PCa.
Currently, ultrasonography-guided biopsy is the most widely used method in the detection of prostate cancer (PCa). However, the sensitivity of the technique is low (39 % - 52 %). In this work, Magnetic Resonance Spectroscopy (MRS) and Diffusion-Weighted Imaging (DWI) will be studied regarding their ability to detect and localize prostatic lesions. Eighteen male patients, who underwent prostate biopsy were studied. A total of 11 patients were diagnosed with PCa, with a modal Gleason Score (GS) of 7; 4 had chronic prostatitis and 3 had negative histological results. Spectroscopy and diffusion by MRI were used to study prostate lesions, and the parenchyma of the central and healthy peripheral zones of the gland. Values of choline/citrate (Cho/Ci) and Apparent Diffusion Coefficient (ADC) were measured. Descriptive and comparative statistics were applied. In patients with PCa, differences were observed between the mean values of Cho/Ci (p=0,000) and ADC (p=0,000) in lesions and healthy peripheral parenchyma. In patients with negative histology, there were differences observed between the mean values of Cho/Ci in suspected lesions and healthy peripheral parenchyma (p=0,006). The Cho/Ci of lesions was positively correlated with GS (rS=0,677; p=0,045). Results show that MRS and DWI are able to identify and locate tumor lesions and suspected areas, thus having the potential to guide biopsy in the study of PCa.
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MEDICINA, MEIOS DE DIAGNÓSTICO E TERAPÊUTICA, RESSONÂNCIA MAGNÉTICA, ESPECTROSCOPIA, CANCRO DA PRÓSTATA, MEDICINE, MAGNETIC RESONANCE IMAGING, DIAGNOSTIC AND THERAPEUTIC PROCEDURES, SPECTROSCOPY, PROSTATE CANCER, ESTUDOS DE CASO, CASE STUDIES