title: Extent of resection of peritumoral diffusion tensor imaging-detected abnormality as a predictor of survival in adult glioblastoma patients.
abstract: OBJECTIVE Diffusion tensor imaging (DTI) has been shown to detect tumor invasion in glioblastoma patients and has been applied in surgical planning. However, the clinical value of the extent of resection based on DTI is unclear. Therefore, the correlation between the extent of resection of DTI abnormalities and patients' outcome was retrospectively reviewed. METHODS A review was conducted of 31 patients with newly diagnosed supratentorial glioblastoma who underwent standard 5-aminolevulinic acid-aided surgery with the aim of maximal resection of the enhancing tumor component. All patients underwent presurgical MRI, including volumetric postcontrast T1-weighted imaging, DTI, and FLAIR. Postsurgical anatomical MR images were obtained within 72 hours of resection. The diffusion tensor was split into an isotropic (p) and anisotropic (q) component. The extent of resection was measured for the abnormal area on the p, q, FLAIR, and postcontrast T1-weighted images. Data were analyzed in relation to patients' outcome using univariate and multivariate Cox regression models controlling for possible confounding factors including age, O6-methylguanine-DNA-methyltrans-ferase methylation status, and isocitrate dehydrogenase-1 mutation. RESULTS Complete resection of the enhanced tumor shown on the postcontrast T1-weighted images was achieved in 24 of 31 patients (77%). The mean extent of resection of the abnormal p, q, and FLAIR areas was 57%, 83%, and 59%, respectively. Increased resection of the abnormal p and q areas correlated positively with progression-free survival (p = 0.009 and p = 0.006, respectively). Additionally, a larger, residual, abnormal q volume predicted significantly shorter time to progression (p = 0.008). More extensive resection of the abnormal q and contrast-enhanced area improved overall survival (p = 0.041 and 0.050, respectively). CONCLUSIONS Longer progression-free survival and overall survival were seen in glioblastoma patients in whom more DTI-documented abnormality was resected, which was previously shown to represent infiltrative tumor. This highlights the potential usefulness and the importance of an extended resection based on DTI-derived maps.
authors.affiliation: Cambridge Brain Tumor Imaging Laboratory, Division of Neurosurgery.|Wolfson Brain Imaging Centre, Department of Clinical Neuroscience, and.|Department of Neurosurgery, Chang Gung Memorial Hospital, Keelung.|Chang Gung University College of Medicine, Taoyuan, Taiwan; and.
authors.forename: Jiun-Lin
authors.initials: JL
authors.lastname: Yan
authors.affiliation: Cambridge Brain Tumor Imaging Laboratory, Division of Neurosurgery.|Department of Radiology, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.|Department of Radiology, University Medical Centre Groningen, University of Groningen, The Netherlands.
authors.forename: Anouk
authors.initials: A
authors.lastname: van der Hoorn
authors.affiliation: Cambridge Brain Tumor Imaging Laboratory, Division of Neurosurgery.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Larkin
authors.affiliation: Cambridge Brain Tumor Imaging Laboratory, Division of Neurosurgery.
authors.forename: Natalie R
authors.initials: NR
authors.lastname: Boonzaier
authors.affiliation: Department of Radiology, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Matys
authors.affiliation: Cambridge Brain Tumor Imaging Laboratory, Division of Neurosurgery.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Price
mesh_terms: D000328:Adult; D000368:Aged; D000622:Aminolevulinic Acid; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging / Q000601:surgery; D003287:Contrast Media; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics / Q000378:metabolism; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D056324:Diffusion Tensor Imaging; D005260:Female; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000235:genetics / Q000401:mortality / Q000601:surgery*; D006801:Humans; D007521:Isocitrate Dehydrogenase / Q000235:genetics; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D011379:Prognosis; D012189:Retrospective Studies; D015173:Supratentorial Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics / Q000401:mortality / Q000601:surgery*; D016019:Survival Analysis; D047368:Tumor Burden; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D025521:Tumor Suppressor Proteins; D000622:Aminolevulinic Acid; D007521:Isocitrate Dehydrogenase; C543588:IDH1 protein, human; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes
keywords: 5-Ala = 5-aminolevulinic acid; DT = diffusion tensor; DTI = diffusion tensor imaging; EOR = extent of resection; FLAIR = fluid-attenuated inversion recovery; FLIRT = FMRIB Linear Image Registration Tool; FMRIB = Oxford Centre for Functional MRI of the Brain; FOV = field of view; FSL = FMRIB Software Library; HR = hazard ratio; IDH-1 = isocitrate dehydrogenase-1; MGMT = O6-methylguanin-DNA-methyltransferase; diffusion tensor imaging; extent of resection; glioblastoma; oncology; p = isotropic component; prognosis; progression-free survival; q = anisotropic component; volumetric study