RESUMO
OBJECTIVES: Conventional methods of imaging neuroendocrine tumors with computed tomography, magnetic resonance imaging, indium-111-octreotide, or radiolabeled metaiodobenzilguanidine scintigraphy have limitations. This pilot study tried to improve the localization of these tumors with fluorine-18-fluorodihydroxyphenylalanine (F-DOPA) positron-emission tomography (PET) scanning. MATERIALS AND METHODS: We studied 22 patients, the majority of whom were referred with clinical diagnosis or suspicion of carcinoid (n = 11), neuroendocrine tumors (n = 7) or pheochromocytoma/paraganglioma (PGL) (n = 4). The comparison was made with the prior conventional imaging. RESULTS: The F-DOPA findings were compared with the results of subsequent surgery (2), endoscopy (1), or a long-term follow-up (mean duration, 49 months) for 17 patients. Two patients were lost to follow-up. Foci of F-DOPA deposition were detected in eight patients (final diagnosis of carcinoid in six, of neuroendocrine tumors in one, and of PGL in another). Comparison with the final diagnoses revealed concordance in 16 of the 22 patients. F-DOPA results appeared superior to those obtained with conventional imaging. Despite the small number and diagnostic heterogeneity, in a substantial fraction of patients F-DOPA PET added information relevant to clinical management. CONCLUSION: F-DOPA scanning added prognostic value, particularly when multiple abnormal foci versus a negative examination were considered.
Assuntos
Colecistite Aguda/diagnóstico por imagem , Colecistolitíase/diagnóstico por imagem , Colecistite Aguda/complicações , Colecistite Aguda/diagnóstico , Colecistite Aguda/cirurgia , Colecistolitíase/complicações , Colecistolitíase/diagnóstico , Colecistolitíase/cirurgia , Doenças da Vesícula Biliar/complicações , Doenças da Vesícula Biliar/diagnóstico , Doenças da Vesícula Biliar/diagnóstico por imagem , Doenças da Vesícula Biliar/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Ruptura Espontânea/diagnóstico , Ruptura Espontânea/diagnóstico por imagem , Ruptura Espontânea/etiologia , Ruptura Espontânea/cirurgiaAssuntos
Tumor Carcinoide/diagnóstico por imagem , Compostos de Lítio/uso terapêutico , Tomografia por Emissão de Pósitrons/métodos , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/secundário , Tumor Carcinoide/patologia , Di-Hidroxifenilalanina , Fluordesoxiglucose F18 , Humanos , Compostos de Lítio/efeitos adversos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Masculino , Transtornos do Humor/tratamento farmacológico , Tomografia por Emissão de Pósitrons/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto JovemRESUMO
A 77-year-old man with Gleason score 7 prostate cancer, after radical prostatectomy, in whom the prostate-specific antigen level increased to 5.0 ng/mL 8 years later, underwent a ProstaScint scan. Radiotracer deposition was noted in the prostatic "fossa," highly suspicious of recurrence. An additional focus in the mid abdomen was suspicious of adenopathy. Computed tomography disclosed an abdominal mass that, at biopsy, proved to be a malignant B-cell lymphoma. That lesion resolved after chemotherapy, and the prostate-specific antigen level substantially decreased with hormonal treatment. The possible association of prostate cancer and lymphoma is discussed.