RESUMO
OBJECTIVE: Focal thyroid incidentaloma (TI) occurs in a 2% of 18F-FDG PET/CT and about one-third of TIs is cancer. Due to the lack of evidence on the optimal management of TI, current guidelines suggest performing fine-needle aspiration cytology (FNA). The study aim was to evaluate the reliability of ACR-TIRADS, EU-TIRADS, and K-TIRADS in indicating FNA in TIs. DESIGN: We retrospectively reviewed 18F-FDG PET/CT TIs recorded during the period 2016-2019. Enrolled were TIs with histologic outcome and autonomous nodules. Cases with uncertain matching between 18F-FDG PET/CT, US/scintiscan and histology were excluded. RESULTS: Eighty TIs at 18F-FDG PET/CT (median size 17 mm, median SUVmax 7.85) were included; a 26.2% was cancer. The percentage of nodules classified as high risk according to ACR-TIRADS, EU-TIRADS, and K-TIRADS was 20%, 30%, and 29.8%, respectively. The cancer prevalence in high-risk class was 56.2%, 66.7%, and 65.2% in ACR-TIRADS, EU-TIRADS, and K-TIRADS, respectively. ACR-TIRADS had the lowest number of cases with FNA indication (48%) and the K-TIRADS, the highest one (75%). Evaluating the reliability of the three systems in indicating FNA, we found a 100% sensitivity and NPV for EU-TIRADS and K-TIRADS; while all the three systems showed poor specificity and PPV. CONCLUSION: All TIRADSs were reliable to stratify the risk of cancer in focal TI. Comparing their reliability in indicating FNA, we found a good performance of EU-TIRADS and K-TIRADS. Considering the high cancer percentage expected in this setting of patients, those TIRADS with higher propensity to indicate FNA should be preferred.
Assuntos
Adenoma/diagnóstico , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Adenoma/patologia , Adulto , Idoso , Biópsia por Agulha Fina/normas , Europa (Continente) , Feminino , Fluordesoxiglucose F18 , Humanos , Achados Incidentais , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Guias de Prática Clínica como Assunto/normas , Padrões de Prática Médica/normas , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Sociedades Médicas/normas , Neoplasias da Glândula Tireoide/patologiaRESUMO
This study assessed the role of 18F-FDG PET-CT (PET/CT) to detect the cartilage and paraglottic infiltration in advanced glottic cancer comparing the results with those of conventional imaging (CI) (contrast-enhanced computed tomography and/or magnetic resonance). In addition, we assessed the prognostic value of quantitative parameters, measured on baseline PET/CT, in terms of event-free survival (EFS) and overall survival (OS). We retrospectively analyzed 27 patients with glottic squamous cell carcinoma stage III and IVA, treated in our institute between 2010 and 2016, comparing PET/CT, performed for staging and radiotherapy planning, and CI findings. Cohen's K was used to compare concordance between PET/CT and CI. Imaging findings were correlated with endoscopic evaluation and histological reports (gold standard (GS)). All lesions shown by CI were also detected by PET/CT imaging, and in 5 cases, a better definition of local infiltration was achieved with PET/CT than CI (5 CT). Sensitivity, specificity, and accuracy of PET/CT and CT were 95%, 86%, and 93% and 70%, 86%, and 74% for, respectively. MRI showed sensitivity and specificity of 100%. One false-negative (FN) cases and 1 false-positive (FP) case were observed with PET/CT with no difference compared to MRI (10 cases). Six FN cases and 1 FP case were observed with CT. Cohen's K was 0.60 (PET vs. CI) and 0.80 (PET vs. GS). Patients were followed-up for at least 24 months to calculate EFS and OS. 13 local recurrence and 7 deaths were recorded. Among quantitative PET parameters, baseline MTV was the most powerful predictor of outcome. Our data suggest a reliable sensitivity and accuracy of PET/CT in the evaluation of local extension, proving a useful method for initial local staging in addition to the well-established role in lymph-node and distant sites assessment. Furthermore, pretreatment MTV provides better prognostic information than other PET/CT parameters.