RESUMO
AIM: The aim of the present study is to raise awareness of ENT Surgeons on the limitations of 18F-FDG PET/CT in head and neck cancer by presenting illustrative cases from our department archives. MATERIALS AND METHODS: A retrospective chart review was conducted for all patients with head and neck cancer treated in our ENT department from 2015 to 2020. Cases with various interpretation pitfalls due to false-positive and false-negative PET/CT results that lead to diagnostic dilemmas and treatment delays either in their pre-therapeutic work-up or in their post-therapeutic monitoring were included. RESULTS: Five cases of various image interpretation pitfalls (3 false negative and 2 false positive cases) were identified and are presented in detail. CONCLUSIONS: Although 18F-FDG PET/CT has gained in popularity and improved head and neck cancer management, clinicians should be aware of its limitations. The combination of 18F-FDG PET/CT with other imaging modalities can reduce the number of interpretation pitfalls but by no means will substitute sound clinical judgement.
Assuntos
Radioisótopos de Flúor , Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Adulto , Idoso , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
Conventional diagnostic imaging is often ineffective in revealing the underlying cause in a considerable proportion of patients with fever of unknown origin (FUO). The aim of this study was to assess the diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in patients with FUO. We retrospectively reviewed 18F-FDG-PET/CT scans performed on 50 consecutive adult patients referred to our department for further investigation of classic FUO. Final diagnosis was based on histopathological and microbiological findings, clinical criteria, or clinical follow-up. Final diagnosis was established in 39/50 (78%) of the patients. The cause of FUO was infection in 20/50 (40%), noninfectious inflammatory diseases in 11/50 (22%), and malignancy in 8/50 (16%) patients. Fever remained unexplained in 11/50 (22%) patients. 18F-FDG-PET/CT scan substantially contributed to the diagnosis in 70% of the patients, either by identifying the underlying cause of FUO or by directing to the most appropriate site for biopsy. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of 18F-FDG-PET/CT for active disease detection in patients with FUO were 94.7%, 50.0%, 84.0%, 85.7%, and 75.0%, respectively. In conclusion, whole-body 18F-FDG-PET/CT is a highly sensitive method for detection of the underlining cause of FUO or for correctly targeting suspicious lesions for further evaluation.
RESUMO
Peritoneal lymphomatosis, defined as the disseminated intraperitoneal lymphomatous infiltration, is a rare presentation usually of non-Hodgkin lymphoma and is associated with aggressive histological subtypes of the malignancy. Recently, the term "peritoneal super scan" has been introduced in positron emission tomography/computed tomography (PET/CT) in a patient with Burkitt lymphoma to describe hypermetabolic lymphomatous involvement of the entire peritoneum, leading to suppression of tracer uptake in organs with otherwise normally increased fluorine-18-fluorodeoxyglucose (18F-FDG) uptake. Herein, we report on a patient with Burkitt lymphoma, initially presenting with a peritoneal super scan in PET/CT demonstrating complete metabolic response to R-CHOP (rituximab, cyclophosphamide, adriamycin, vincristine, and prednisolone) therapy.
