Functional brain mapping using positron emission tomography scanning in preoperative neurosurgical planning for pediatric brain tumors

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>The purpose of this report is to demonstrate the value of functional brain mapping using the positron emission tomography (PET) method for preoperative neurosurgical planning in children with brain tumors. Brain maps were used to characterize the relationship between potentially resectable tumors and functionally eloquent brain areas.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Five children, ranging in age from 3 to 13 years, with hemispheric brain tumors adjacent to eloquent cortex were studied. Magnetic resonance (MR) imaging was used to identify the brain tumors; PET imaging after injection of [<jats:sup>18</jats:sup>F]fluorodeoxyglucose (FDG), [<jats:sup>11</jats:sup>C]<jats:sc>l</jats:sc>-methionine (CMET), or a combination of the two was performed to grade the tumors; and a [<jats:sup>15</jats:sup>O] H<jats:sub>2</jats:sub>O uptake study was used to characterize the anatomical relationships of the tumors to functional cortex. The cortical activation maps were obtained during control periods and during behavioral tasks and were used to document motor, visual, and speech and language organizational areas. Wada tests were performed in two patients. Language and speech activation was concordant with the results of Wada testing.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Functional brain mapping using PET scans and coregistered MR images provided the neurosurgeon with precise definitions of structural and functional cortical areas; this altered surgical management in some cases and/or was used to predict outcome. The combination of PET imaging with FDG and/or CMET and measurements of [<jats:sup>15</jats:sup>O] water uptake was useful in characterizing and grading tumors and instrumental in achieving effective neurosurgical planning. Postoperative results in the five cases suggest that preoperative functional brain mapping has the potential to improve outcome by defining a surgical plan to maximize resection and minimize the risk of neurological sequelae.</jats:p></jats:sec>

Magnetocephalography: a noninvasive alternative to the Wada procedure

“…With recent improvements in the sampling density of magnetic sensors, it is now possible reliably to record and model brain activity associated with the engagement of anterior language areas in the performance of expressive tasks (such as word-fluency and picture-naming tasks). Brain activation protocols that target these regions have been successfully used in the context of hemodynamic imaging methods 1,12,17 and are expected to complement existing protocols to further increase the selectivity of MEG-derived estimates of hemispheric dominance for language function. Accumulated experience with the study of more than 240 patients and 100 healthy control volunteers who had undergone presurgical language mapping by using identical procedures prompted a number of revisions in the MEG data analysis procedures to ensure data integrity.…”

Integrated positron emission tomography and magnetic resonance imaging–guided resection of brain tumors: a report of 103 consecutive procedures

“…Positron emission tomography scanning provides independent and complementary information on the level and distribution of brain tumor metabolism, 1,17,21,33,43,58,59 especially with two tracers: FDG, which assesses glucose metabolism, and MET, which assesses amino acid transport and protein metabolism.…”

Pediatric CNS Tumors

“…However, 18 FDG cannot be normally metabolized and, therefore, becomes entrapped within cells (Wang et al 1996a) . For pediatric brain scans, 0.14 mCi/kg of 18 FDG is given intravenously and images are usually obtained 30 min later (Kincaid et al 1998 ;Kaplan et al 1999) . For pediatric brain scans, 0.14 mCi/kg of 18 FDG is given intravenously and images are usually obtained 30 min later (Kincaid et al 1998 ;Kaplan et al 1999) .…”

“…Preoperative use of PET was originally presented by LeBlanc and Meyer (1990) and Leblanc et al (1992 Kaplan et al to create functional maps prior to brain tumor resection in a pediatric population (Kaplan et al 1999 PET has also been used to select targets for biopsy within brainstem tumors ) . MEG relies on the ability to detect single dipole magnetic fi elds created by the pooled activity of groups of neurons to defi ne potential areas of seizure activity (Chuang et al 1995 ;) .…”