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Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Adenocarcinoma , Colecistite , Radioisótopos de Flúor/farmacocinética , Vesícula Biliar/metabolismo , Neoplasias da Vesícula Biliar , Melanoma/secundário , Tomografia Computadorizada de Emissão , Compostos Radiofarmacêuticos/farmacocinética , Fluordesoxiglucose F18/farmacocinética , Tomografia Computadorizada por Raios X , Compostos Radiofarmacêuticos , Adenocarcinoma/complicações , Adenocarcinoma , Colecistite/complicações , Fluordesoxiglucose F18 , Achados Incidentais , Neoplasias Esofágicas/complicações , Neoplasias EsofágicasRESUMO
Purpose: To assess the clinical accuracy of whole-body 2-[F-18]-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) in the diagnosis of recurrent colorectal carcinoma in comparison to conventional computed tomography (CT).Materials and methods: Forty patients with suspected recurrent colorectal carcinoma based on either progressive serial carcinoemrbyonic antigen (CEA) serum elevation or positive/equivocal CT findings underwent whole-body FDG-PET. PET results were compared with those of CT and correlated to the final histopathological and clinical findings.Results: A final diagnosis was obtained at 93 sites in 35 patients by histology and in 5 patients by clinical follow up of at least 6 months. Of the 93 sites, 53 were determined to be malignant and 40 benign. FDG-PET evaluated on a 5-point scale (0-4) showed a positive and negative predictive value in the range of 96-98% and 83-93% respectively as the threshold for positivity was moved from 0 through 3. By comparison, CT, also evaluated on a 5-point scale showed a positive and negative predictive value in the range of 75-88% and 67-71% respectively. The area under the fitted receiver operating characteristic curve for PET: A(PET) = 0.96 +/- 0.02 was significantly greater (P < 0.001) than that observed for CT: A(CT) = 0.77 +/- 0.06. The distribution of maximum standardized uptake value (SUVmax) showed that all negative lesions have SUVmax below 5.0 whereas 75% of positive lesions were above 5.0 pointing to the fact that disease positivity is more likely in lesions with high SUV values.Conclusion: The results of this study confirm that whole-body FDG-PET is more accurate than conventional CT in the staging of patients with suspected recurrent colorectal carcinoma.
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Three patients were diagnosed with carcinoid tumors of the kidney. The diagnosis was rendered after biopsy with the assistance of immunohistochemical stains. In all three patients, a pentetreotide scan was helpful in staging. Metastatic disease that was not evident by computed tomography was found in one patient. All three patients are alive with stable or slowly progressive disease at 33, 36, and 40 months. Carcinoid tumors arising from the kidney are rare but must be considered in the differential diagnosis of a renal mass. Immunohistochemical staining is important in the diagnosis of these tumors and the pentetreotide scan contributes to accurate staging.