title: High-resolution 1H-magnetic resonance spectroscopy of pediatric posterior fossa tumors in vitro.
abstract: High-resolution proton magnetic resonance (MR) spectroscopy was performed on perchlorate extracts of tumors (24 cases) or peritumoral vermis (five cases) obtained at surgery. Fifteen tumors were typical cerebellar astrocytomas and nine were posterior fossa primitive neuroectodermal tumors/medulloblastomas. Spectra obtained from the five samples of peritumoral vermis revealed a pattern of metabolites similar to that reported for cerebellar tissue, but concentrations of most metabolites were low, perhaps due to dilution from peritumoral edema. The astrocytomas were characterized by high levels of valine, alanine, and choline, an increase in the choline:N-acetylaspartate (NAA) ratio, and a shift from glutamate to glutamine. Elevations in lactate, pyruvate, and glucose were the result of ischemia during sampling. The primitive neuroectodermal tumors/medulloblastomas were distinguished from astrocytomas by a greater increase in the choline:NAA ratio, a smaller decrease in the glutamate:glutamine ratio, and a relative increase in glycine, taurine, and inositol levels. These metabolic patterns may be of value diagnostically as in vivo MR spectroscopy achieves higher resolution.
authors.affiliation: Children's Hospital of Philadelphia, Pennsylvania.
authors.forename: L N
authors.initials: LN
authors.lastname: Sutton
authors.forename: S L
authors.initials: SL
authors.lastname: Wehrli
authors.forename: L
authors.initials: L
authors.lastname: Gennarelli
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: R
authors.initials: R
authors.lastname: Zimmerman
authors.forename: K
authors.initials: K
authors.lastname: Bonner
authors.forename: L B
authors.initials: LB
authors.lastname: Rorke
mesh_terms: D000293:Adolescent; D000409:Alanine / Q000032:analysis; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001254:Astrocytoma / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism*; D002528:Cerebellar Neoplasms / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D002794:Choline / Q000032:analysis; D003388:Cranial Fossa, Posterior; D005971:Glutamates / Q000032:analysis; D018698:Glutamic Acid; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D009682:Magnetic Resonance Spectroscopy; D008527:Medulloblastoma / Q000378:metabolism*; D017599:Neuroectodermal Tumors / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000032:analysis; D051381:Rats; D014633:Valine / Q000032:analysis
chemical_list: D000596:Amino Acids; D005971:Glutamates; D018377:Neurotransmitter Agents; D001224:Aspartic Acid; D018698:Glutamic Acid; C000179:N-acetylaspartate; D014633:Valine; D002794:Choline; D000409:Alanine