A metodologia ROC na avaliação de um modelo fuzzy de predição do estádio patológico do tumor de próstata

Resumo

In recent years, the increase in the incidence of prostate cancer has become a major public health problem and a challenge for medical science. The goal of this work is assessing the performance of a mathematical model, developed by Silveira (2007) to predict the pathological stage of the prostate cancer, through ROC methodology (Receiver Operating Characteristic). The model is a fuzzy rulebased system, that combines pre-surgical data – clinical stage, PSA level and Gleason score – availing of a set of linguistic rules made with base on information of the existents nomograms. The output of the system provides the possibilities of the individual, with certain clinical features, be in each stage of the tumor extension: localized, advanced locally and metastatic. To analyze the discriminatory power of the fuzzy model as a diagnosis test, was constructed from the measures of sensitivity and specificity, the ROC curve and calculated the total area under the curve, as measure of performance. Moreover, were obtained (in two different ways) the cutoff points most “appropriate”, that is a threshold for deciding between the disease is fully localized within the prostate gland or not. Real data of patients from the Clinics Hospital of UNICAMP were used in the calculations and the surgery – radical prostatectomy – was used as gold standard. The results showed that the fuzzy model in question can be used to discriminate localized prostate cancer.

Descrição

Palavras-chave

Câncer de próstata, Diagnóstico, Conjuntos fuzzy, Curva ROC, Prostate cancer, Diagnosis, Fuzzy sets, ROC curve

Citação

SILVEIRA, Graciele Paraguaia; BARROS, Laécio Carvalho de; VENDITE, Laércio Luis; FERREIRA, Ubirajara; BILLIS, Athanase. A metodologia ROC na avaliação de um modelo fuzzy de predição do estádio patológico do tumor de próstata. Revista Brasileira de Engenharia Biomédica, Rio de Janeiro, v. 26, n. 1, p. 3-9, abril 2010.