title: Comparison of diffusion tensor imaging and11C-methionine positron emission tomography for reliable prediction of tumor cell density in gliomas.
abstract: OBJECTIVE Diffusion MRI is attracting increasing interest for tissue characterization of gliomas, especially after the introduction of antiangiogenic therapy to treat malignant gliomas. The goal of the current study is to elucidate the actual magnitude of the correlation between diffusion MRI and cell density within the tissue. The obtained results were further extended and compared with metabolic imaging with11C-methionine (MET) PET. METHODS Ninety-eight tissue samples from 37 patients were stereotactically obtained via an intraoperative neuronavigation system. Diffusion tensor imaging (DTI) and MET PET were performed as routine presurgical imaging studies for these patients. DTI was converted into fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps, and MET PET images were registered to Gd-administered T1-weighted images that were used for navigation. Metrics of FA, ADC, and tumor-to-normal tissue ratio of MET PET along with relative values of FA (rFA) and ADC (rADC) compared with normal-appearing white matter were correlated with cell density of the stereotactically obtained tissues. RESULTS rADC was significantly lower in lesions obtained from Gd-enhancing lesions than from nonenhancing lesions. Although rADC showed a moderate but statistically significant negative correlation with cell density (p = 0.010), MET PET showed a superb positive correlation with cell density (p < 0.0001). On the other hand, rFA showed little correlation with cell density. CONCLUSIONS The presented data validated the use of rADC for estimating the treatment response of gliomas but also caution against overestimating its limited accuracy compared with MET PET.
authors.affiliation: Department of Neurosurgery, Osaka Medical Center for Cancer and Cardiovascular Diseases;|Departments of 2 Neurosurgery.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kinoshita
authors.affiliation: Departments of 2 Neurosurgery.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Arita
authors.affiliation: Department of Neurosurgery, Osaka National Hospital, National Hospital Organization, Osaka, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Okita
authors.affiliation: Departments of 2 Neurosurgery.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kagawa
authors.affiliation: Departments of 2 Neurosurgery.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Kishima
authors.affiliation: Departments of 2 Neurosurgery.
authors.forename: Naoya
authors.initials: N
authors.lastname: Hashimoto
authors.affiliation: Radiology, and.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Radiology, and.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine; and.
authors.forename: Eku
authors.initials: E
authors.lastname: Shimosegawa
authors.affiliation: Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine; and.
authors.forename: Jun
authors.initials: J
authors.lastname: Hatazawa
authors.affiliation: Departments of 2 Neurosurgery.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Departments of 2 Neurosurgery.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Yoshimine
mesh_terms: D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D002452:Cell Count; D056324:Diffusion Tensor Imaging; D005910:Glioma / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008715:Methionine; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results
chemical_list: D019275:Radiopharmaceuticals; C086242:carbon-11 methionine; D008715:Methionine
keywords: 11C-methionine positron emission tomography; AD; ADC = apparent diffusion coefficient; DTI; DTI = diffusion tensor imaging; FA; FA = fractional anisotropy; MET = 11C-methionine; T/Nr = tumor-to-normal tissue ratio; VOI = voxel of interest; apparent diffusion coefficient; cell density; diffusion tensor imaging; fractional anisotropy; oncology; rADC = relative value of ADC; rFA = relative value of FA