Magnetic resonance imaging of midline pediatric cerebral neoplasms

Controversy pertaining to therapeutic modalities for tumors of the pineal region: a worldwide survey of different patient populations

The management of tumors of the pineal region differs between Western countries and Japan. This paper reports on a worldwide survey of individual experience and regimens for treating pineal region tumors in different patient populations. Fifteen pediatric neurosurgeons from nine different countries participated in the survey, and a total of 408 pineal region tumors were evaluated. Determination of tumor histology as an initial procedure was strongly supported by the majority of neurosurgeons in North and Central America and Europe (group A), whereas all but one from Asia and Egypt (group B) emphasized initial application of the radiation test. The analysis of patient populations clearly revealed racial differences in tumor type which explain this discrepancy. Germinoma, the most radiosensitive tumor, constituted 43-70% (mean: 53.7%) of tumors in group B, followed by teratoma, pineoblastoma, and others, whereas in group A the incidence of germinoma was only 21-44% (mean: 34.7%), followed by a variety of tumors, such as astrocytoma, pineoblastoma, etc. The age distribution among intracranial germ cell tumors (GCT) obtained from data from the Brain Tumor Registry in Japan also demonstrated clear differences in the incidence of tumor types in different age groups in Japan: while germinoma constituted 70-84% of GCT in patients between the ages of 15 and 35 years, the incidence was much lower before 15 years and after 35 years, being 24% of tumors under 4 years and 34% of tumors after 40 years of age. The therapeutic regimen for pineal region tumors should depend on the patient population concerned, because of the differences relating to race and age distribution.

Gadolinium-enhanced MR imaging in the management of a midline cerebral dysgerminoma

Magnetic Resonance (MR) imaging has proved to be an excellent modality for the evaluation of CNS tumors and detection of metastatic seeding through CNS pathways. We present a case of cerebral dysgerminoma in which the use of gadopentetate dimeglumine (Gd-DTPA) enhancement added important information in lesion detection and delineation for treatment planning. Our results, and a review of recent literature, suggest that Gd-DTPA-enhanced MR imaging may be useful for initial and follow-up evaluation of CNS dysgerminomas.

A comparative study of CT and MRI in midline tumors of childhood and adolescence

In order to compare the validity of CT and MRI, we evaluated results of these studies in 40 children and adolescents suffering from supratentorial and infratentorial midline tumors. Plain and enhanced CT scans were compared with MRI for sensitivity, specificity and capacity to delineate the tumor. These parameters were evaluated by three independent investigators on a scale with four grades of accuracy. The results demonstrate greater sensitivity and better delineation of the tumor with MRI, but greater specificity in diagnosis of tumors with CT studies.

Magnetic resonance imaging of midline pediatric cerebral neoplasms

Over 80 cases of pediatric cerebral disease including 60 brain tumors, have been studied by low field 0.12 Tesla resistive NMR proton imaging. In addition, experience has been gained with proton imaging on a superconducting high field 1.5 Tesla system. Comparison of NMR images at both field strength, and comparison of the images to those obtained with high resolution CT is made. Examples of how NMR images can help to plan patient management is presented.