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

Object. The purpose of this report is to demonstrate the value of functiona l brain mapping using the positron emission tomography (PET) method for pre operative neurosurgical planning in children with brain tumors. Brain maps were used to characterize the relationship between potentially resectable t umors and functionally eloquent brain areas. Methods. 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 injec tion of [F-18]fluorodeoxyglucose (FDG), [C-11]L-methionine (CMET), or a com bination of the two was per formed to grade the tumors; and a [O-15] H2O up take study was used to characterize the anatomical relationships of the tum ors to functional cortex. The cortical activation maps were obtained during control periods and during behavioral tasks and were used to document moto r, visual, and speech and language organizational areas. Wada tests were pe rformed in two patients. Language and speech activation was concordant with the results of Wada testing. Conclusions. Functional brain mapping using PET scans and coregistered MR i mages provided the neurosurgeon with precise definitions of structural and functional cortical areas, this altered surgical management in some cases a nd/or was used to predict outcome. The combination of PET imaging with FDG and/or CMET and measurements of [O-15] water uptake was useful in character izing and grading tumors and instrumental in achieving effective neurosurgi cal planning. Postoperative results in the five cases suggest that preopera tive functional brain mapping has the potential to improve outcome by defin ing a surgical plan to maximize resection and minimize the risk of neurolog ical sequence.