Utilidad de la tomografía por emisión de positrones con 18F-fluorodesoxiglucosa-tomografía computarizada en la identificación del tumor primario en pacientes con cáncer de origen desconocido / Usefulness of 18F-fluorodeoxiglucose-positron emission tomography-computerized tomography in the identification of the primary tumor in patients with cancer of unknown origin

Fundamento y objetivo: Valorar la utilidad de la técnica positron emission tomography (PET, «tomografía por emisión de positrones») con 18F-fluorodesoxiglucosa (18F-FDG) combinada con tomografía computarizada (TC) en la localización del tumor primario en pacientes diagnosticados de tumor de origen desconocido (TOD). Pacientes y método: Se analizaron retrospectivamente los estudios PET-TC con 18F-FDG realizados, entre noviembre de 2006 y noviembre de 2010, a pacientes con el diagnóstico de TOD para búsqueda de tumor primario. A todos los pacientes se les realizó un estudio estándar PET-TC, 50-60 minutos después de la administración intravenosa de 296-370MBq de 18F-FDG. Se valoraron los estudios PET-TC en patológicos, con/sin identificación del tumor primario, y no patológicos. El diagnóstico final se estableció mediante confirmación histológica y/o seguimiento clínico/radiológico superior a 6 meses. Resultados: Setenta y cuatro pacientes fueron estudiados (59 varones, 15 mujeres), con un intervalo de edad de 41-89 años. En 38 (51%) pacientes la PET-TC determinó correctamente el origen del tumor primario, realizándose confirmación histológica en 8 casos sobre el mismo. En 4 pacientes la PET-TC mostró un resultado falso positivo. Conclusión: La técnica PET-TC permitió identificar el 51% de los tumores primarios en nuestra muestra de pacientes (AU)

Background and objective: We determined the utility of the18F-fluorode oxyglucose (18F-FDG) positron emission tomography (PET)-computerized tomography (CT) in the localization of the primary tumor in patients with tumor of unknown origin (TUO).Patients and method:18F-FDG PET-CT scans, performed between November 2006 and November 2010, in search for the primary tumor in patients with TUO, were retrospectively evaluated. Patients underwent a standard PET-CT, 50-60 minutes after intravenous injection of 296-370 MBq18F-FDG. PET-CT studies were assessed as pathological, with/without identification of the primary tumour and no pathological. Final diagnosis was established by histological confirmation and/or clinical/radiologic follow-up longer than 6 months. Results: We studied 74 patients (59 males, 15 females), with ages ranging from 41-89 years. In 38 (51%) patients the PET-CT assessed the correct origin of the primary tumour. In 8 cases, a histological confirmation in the primary lesion was obtained. In 4 patients the PET-CT showed a false positive result. Conclusion: PET-CT scanning identified 51% of the primary sites in our sample of patients (AU)

[Usefulness of (18)F-fluorodeoxyglucose-positron emission tomography-computerized tomography in the identification of the primary tumor in patients with cancer of unknown origin]. / Utilidad de la tomografía por emisión de positrones con (18)F-fluorodesoxiglucosa-tomografía computarizada en la identificación del tumor primario en pacientes con cáncer de origen desconocido.

BACKGROUND AND OBJECTIVE: We determined the utility of the (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)-computerized tomography (CT) in the localization of the primary tumor in patients with tumor of unknown origin (TUO). PATIENTS AND METHOD: (18)F-FDG PET-CT scans, performed between November 2006 and November 2010, in search for the primary tumor in patients with TUO, were retrospectively evaluated. Patients underwent a standard PET-CT, 50-60minutes after intravenous injection of 296-370MBq (18)F-FDG. PET-CT studies were assessed as pathological, with/without identification of the primary tumour and no pathological. Final diagnosis was established by histological confirmation and/or clinical/radiologic follow-up longer than 6 months. RESULTS: We studied 74 patients (59 males, 15 females), with ages ranging from 41-89 years. In 38 (51%) patients the PET-CT assessed the correct origin of the primary tumour. In 8 cases, a histological confirmation in the primary lesion was obtained. In 4 patients the PET-CT showed a false positive result. CONCLUSION: PET-CT scanning identified 51% of the primary sites in our sample of patients.

123-I ioflupane (Datscan®) presynaptic nigrostriatal imaging in patients with movement disorders

123-I Ioflupane (Datscan®) presynaptic imaging has been shown to have a significant utility in the assessment of patients with movement disorders 123-I Ioflupane SPECT is able to distinguish between ParkinsonÆs disease (PD) and other forms of parkinsonism without degeneration of the nigrostriatal pathway, including a common movement disorder such as essential tremor, and to assess disease progression in PD and other neurodegenerative disorders involving the substantia nigra.

A imagem pré-sináptica através de 123-I Ioflupane (Datscan®) tem mostrado um papel significante na avaliação de pacientes com distúrbios do movimento. 123-I Ioflupane SPECT é capaz de distinguir entre Mal de Parkinson (MP) e outras formas de parkinsonismo sem degenerações da via nigroestriatal incluindo um distúrbio comum de movimento parecido com o tremor essencial e para medir a evolução da doença no Mal de Parkinson e outros distúrbios neurodegenerativos envolvendo a substantia nigra.