title: Prediction of anaplastic transformation in low-grade oligodendrogliomas based on magnetic resonance spectroscopy and 1p/19q codeletion status.
abstract: The aim of this study was to assess whether combining multimodal magnetic resonance imaging (MRI) with the determination of the 1p/19q codeletion status could improve the ability to predict anaplastic transformation in low-grade oligodendrogliomas. Twenty patients with grade II oligodendrogliomas were followed-up using multimodal MR [proton MR spectroscopy (MRS), perfusion, and conventional MR imaging]. All patients diagnoses were histologically proven, and 1p/19q codeletion status was analyzed for all patients. Median follow-up was 30.5 ± 11.4 months. Anaplastic transformation was observed in six patients. The only MRI feature that was associated with anaplastic transformation was an elevation of the choline/creatine ratio >2.4 which was observed in 4 out of 6 patients with anaplastic transformation versus 1 out of 14 patients without anaplastic transformation. In patients without 1p/19q codeletion, an elevation of the choline/creatine ratio >2.4 was associated with the occurrence of anaplastic transformation in all cases (4 out of 4 patients), with a mean time of 12 months. In contrast, in patients with a 1p/19q codeletion, no anaplastic transformation was observed in the patient who had an elevation of >2.4 of the choline/creatine ratio and two patients demonstrated an anaplastic transformation without any elevation of this ratio.Prospective validation in a larger series is needed, yet the present study suggests that combining data from in vivo proton MRS and genetic analysis could be a promising strategy to predict time to anaplastic transformation at the individual level in patients with low-grade oligodendrogliomas and may help deciding when chemotherapy and/or radiotherapy should be initiated in these tumors.
authors.affiliation: Department of Neurosurgery, Hôpital Pierre Wertheimer, Hospices civils de Lyon, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bourdillon
authors.forename: Chadi
authors.initials: C
authors.lastname: Hlaihel
authors.forename: Jacques
authors.initials: J
authors.lastname: Guyotat
authors.forename: Laurent
authors.initials: L
authors.lastname: Guillotton
authors.forename: Jérôme
authors.initials: J
authors.lastname: Honnorat
authors.forename: François
authors.initials: F
authors.lastname: Ducray
authors.forename: François
authors.initials: F
authors.lastname: Cotton
mesh_terms: D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002794:Choline / Q000378:metabolism; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D003401:Creatine / Q000378:metabolism; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009837:Oligodendroglioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline