PET/CT com 18-fluor-fluorodeoxiglucose no seguimento do melanoma maligno cutâneo

Background – Cutaneous malignant melanoma (CMM) is one of the most lethal malignancies and the follow-up involves, in addition to clinical examination and analysis of tumor markers, several imaging methods such as the Positron Emission Tomography/Computed Tomography (PET/CT) exam with 18fluor-fluorodeoxyglucose (18F-FDG). The aim of the study is to evaluate the utility of PET/CT in the assessment of the extension of the disease and of suspected recurrence in the CMM, comparing the imaging findings with those described in CT studies. Methods – It was performed a retrospective analysis of 62 PET/CT studies in 50 patients diagnosed with CMM. It was excluded a study which had a doubtful outcome (pulmonary nodule) and it was not possible to perform its diagnosis. The information related to the results of pathologic studies and imaging studies was obtained through medical history and medical reports of CT and PET/CT. A database was created with the collected data through Excel software and a descriptive statistical analysis was carried out. Results – Of the PET/CT studies analyzed, 31 were considered true positives (TP), 28 true negatives (TN), 1 false negative (FN) and 1 false positive (FP). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of PET/CT for staging and evaluation of suspicious relapse in CMM are, respectively, 96.9%, 96.6%, 96.9%, 96.6% and 96.7%. From the CT results considered in statistical analysis, 14 corresponded to TP, 12 to TN, 3 to FP and 5 to FN. The sensitivity, specificity, PPV and NPV, and accuracy of CT for staging and evaluation of suspicious relapse in CMM are, respectively, 73.7%, 80.0%, 82.4%, 70.6% and 76.5%. Comparatively to the CT results, PET/CT allowed a change in therapeutic approach in 23% of studies. Conclusion – PET/CT is a useful tool in evaluating CMM, characterized by high diagnostic accuracy in staging and in the evaluation of suspected recurrence of MMC compared to CT only.