RESUMO
The authors analyzed the results of 11C-methionine positron emission tomography (PET) in 101 patients with suspected recurrent brain tumor. The diagnosis was confirmed in 72 patients. The increased 11C-methionine uptake in the initial tumor area is considered to be a crucial PET evidence of a recurrent tumor. On the other hand, brain tissue histological changes associated with surgery, radiation, and chemotherapy were characterized by the low uptake of the tracer. The sensitivity and specificity of PET scanning in detecting tumor recurrence were found to be 95.8 and 96.5%, respectively. 11C-methionine PET is proposed as a reliable technique for early differentiating between a recurrent brain tumor and treatment-induced nonneoplastic changes.
Assuntos
Neoplasias Encefálicas/patologia , Tomografia por Emissão de Pósitrons/métodos , Adolescente , Adulto , Idoso , Encéfalo/patologia , Encéfalo/efeitos da radiação , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Radioisótopos de Carbono , Criança , Pré-Escolar , Feminino , Glioma/diagnóstico , Glioma/patologia , Humanos , Masculino , Metionina , Pessoa de Meia-Idade , Necrose , Sensibilidade e EspecificidadeRESUMO
The study was based on the data of positron emission tomography (PET) and L-[methyl]-[11C]-methionine used in 117 patients with suspected brain tumor. PET data on 74 patients with histologically verified cerebral tumors were analyzed in detail. New additional criteria for assessing PET scans, which formed the PET syndromes of astrocytomas, anaplastic astrocytomas, and glioblastomas. Operative and histological verification confirmed the high validity of the proposed criteria for defining the type of a tumor.
Assuntos
Astrocitoma/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Metionina , Compostos Radiofarmacêuticos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada de EmissãoRESUMO
Positron emission tomography by using H2(15)O whose distribution in the brain reflects a genuine cerebral blood flow was made in 5 patients with suspected intracranial hematomas. It was shown that tunicary hematomas might be diagnosed by positron emission tomography. However, examination of cerebral blood flow was not optimal in this abnormality. Computerized tomography remains the basic method for diagnosing intracranial hematomas and positron emission tomography should be used to evaluate cerebral function.
Assuntos
Hemorragia Cerebral/diagnóstico por imagem , Hematoma/diagnóstico por imagem , Tomografia Computadorizada de Emissão , Adulto , Encéfalo/diagnóstico por imagem , Lesões Encefálicas/diagnóstico por imagem , Humanos , Pessoa de Meia-Idade , Radioisótopos de OxigênioRESUMO
PET data were compared with the results of computerized tomography (CT) and the neurological status of patients. The areas of decreased local cerebral blood flow (LCBF) and reduced local cerebral metabolic glucose rates exceeded those of brain injury shown by CT predominantly in patients with brain posttraumatic cysts. In a group of patients with posttraumatic atrophy documented by CT, PET demonstrated cortical and/or subcortical lesions in most cases, providing objective evidence for neurological symptoms. PET is a useful technique to demonstrate regional brain dysfunction in the presence of morphological integrity as assessed by CT.
