Comparison of PET and Proton MRS Imaging to Evaluate Pediatric Brain Tumor Activity

Background:

• Children with brain tumors are generally followed for response or progression by imaging studies, such as CT or MRI.
• While these imaging studies help delineate the anatomical location and extent of a tumor within the CNS, they give no information regarding the biologic or metabolic activity of the lesion.
• Proton Nuclear Magnetic Resonance Spectroscopic Imaging ((1)H-MRSI) is a non-invasive method of detecting and measuring cellular metabolites in vivo, providing biochemical information in conjunction with the spatial information obtained by MRI.
• Positron Emission Tomography (PET) is a technique that also provides data on metabolic activity of brain lesions.
• A comparison of these two methods in determining a lesion s metabolic activity has not been reported in children with brain tumors.

Objective:

-To compare (1)H-MRSI and [(18)F-]-FDG PET scanning percentage (%) of agreement between supratentorial and infratentorial tumors, and between brainstem and cerebellum intratentorial tumors.

Eligibility:

• Age: greater than or equal to 1 year and less than to 21 years
• Patients must have a brain tumor that is measurable or evaluable on standard MRI or CT.

Design:

• Patients referred for this study will have both (1)H-MRSI and (18)F-FDG PET imaging performed within 2 weeks of each other at the NCI
• Patients will remain on study for 5 years or until one of the off-study criteria have been met (whichever occurs first)

• INCLUSION CRITERIA:

• Age: greater than or equal to 1 years and less than or equal to 21 years.
• Radiographic diagnosis: Patients must have a brain tumor (including, but not limited to high grade gliomas, low-grade gliomas, primitive neuroectodermal tumors, ependymomas) or residual abnormality (e.g. post-operatively or post-radiation) that is measurable or evaluable on standard MRI or CT.
• All patients or their legal guardians (if the patient is less than 18 years of age) must sign a document of informed consent indicating their awareness of the investigational nature and the risks of this study.
• Prior treatment: Patients will be eligible regardless of prior treatment. Therefore, patients who are newly diagnosed, post-operative, post-radiation or post-chemotherapy are eligible.

Exclusion criteria

• Patients under age 18 years who weigh greater than 70 kg are excluded because they would exceed the standard allowable dosimetry for pediatric patients (i.e. Effective Dose greater than 0.5 REM/year). In addition, patients who weigh greater than 136 kg are excluded, as this is the maximum weight allowable on PET scanner tables.
• Pregnant or breastfeeding women
• Any patient who is unable (either because of physical or psychological factors) to undergo imaging studies without sedation but is not considered an anesthesia candidate.
• Any patient with a metallic MRI incompatible implant, including cardiac pacemakers, neural pacemakers, aneurysmal clips, shrapnel, cochlear implants or ferrous surgical clips.
• Any patient with a history of a severe reaction (CTC v.4 Grade greater than or equal to 2) to Gadolinium or other contrast agents.
• Any patient with Diabetes mellitus or steroid-induced hyperglycemia (fasting glucose greater than 150) because this may interfere with the interpretation of the [(18)F]-FDG PET scan.
• Any patient with permanent braces, permanent retainers or nonferrous implant that, in the judgment of the Principal Investigator, would interfere with obtaining spectroscopy in the area of the tumor.