RESUMO
In patients with malignant astrocytomas or metastatic brain disease treated with high-dose radiotherapy, conventional imaging methods may not adequately distinguish recurrent tumor from radiation change. We used a fast spoiled gradient refocusing technique in the open-configuration intraoperative MR system to assess the rate of regional enhancement of the treated tumor bed and to localize specific sites for pathologic sampling to determine whether gadolinium uptake correlated with histologic data. Twenty-four patients were studied. Fourteen of 15 patients with areas of early enhancement had recurrent tumor present in histologic samples, and 8 of the remaining 9 patients had only reactive changes. Dynamic MRI was predictive of recurrent tumor (P < .0005, Fisher exact test and P < .002, Student t test). We conclude that dynamic MRI in the open-bore magnet is a promising method for localizing potential sites of active tumor growth in patients treated for malignant astrocytomas and metastatic brain lesions.
Assuntos
Neoplasias Encefálicas/patologia , Encéfalo/patologia , Glioblastoma/patologia , Imageamento por Ressonância Magnética/métodos , Recidiva Local de Neoplasia/patologia , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Meios de Contraste , Feminino , Gadolínio DTPA , Glioblastoma/radioterapia , Glioblastoma/cirurgia , Humanos , Cuidados Intraoperatórios/métodos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/cirurgia , Radiocirurgia , Radioterapia de Alta Energia , Sensibilidade e EspecificidadeRESUMO
Eleven patients with intracranial cystic collections were evaluated in the open-bore intraoperative MR system. In each case, the cystic collection or the surrounding cerebrospinal fluid (CSF) space was injected with .02 to .5 cc of .5 mol/l gadopentetate dimeglumine. Serial imaging was performed using T1-weighted imaging. In seven patients, free communication was demonstrated between the cystic collection and the surrounding CSF spaces. In four cases, the cyst did not communicate with the CSF; two of these were drained in the intraoperative MR system with reduction in symptoms. One patient developed an aseptic meningitis 10 days after the study, which was successfully treated with steroids; no other complications were noted. We conclude that the communication of intracranial cystic collections with the cisterns and ventricles can be safely and effectively elucidated with gadolinium injection in the intraoperative MR system.