Apparent Diffusion Coefficient Histogram Analysis Stratifies Progression-Free Survival in Newly Diagnosed Bevacizumab-Treated Glioblastoma

• Published in: American journal of neuroradiology : AJNR 2011-05, Vol.32 (5), p.882-889
• Main Authors: POPE, W. B, LAI, A, TRAN, A, CLOUGHESY, T. F, MEHTA, R, KIM, H. J, QIAO, J, YOUNG, J. R, XUE, X, GOLDIN, J, BROWN, M. S, NGHIEMPHU, P. L
• Format: Article
• Language: English
• Subjects: Angiogenesis Inhibitors - therapeutic use; Antibodies, Monoclonal - therapeutic use; Antibodies, Monoclonal, Humanized; Bevacizumab; Biological and medical sciences; Brain; Brain Neoplasms - drug therapy; Brain Neoplasms - epidemiology; California - epidemiology; Data Interpretation, Statistical; Diffusion Magnetic Resonance Imaging - methods; Diffusion Magnetic Resonance Imaging - statistics & numerical data; Disease-Free Survival; Female; Fundamental and applied biological sciences. Psychology; Glioblastoma - drug therapy; Glioblastoma - epidemiology; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Miscellaneous; Neoplasm Recurrence, Local - epidemiology; Neoplasm Recurrence, Local - prevention & control; Nervous system; Perception; Prevalence; Prognosis; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Risk Assessment; Risk Factors; Treatment Outcome
• ISSN: 0195-6108; 1936-959X; 1936-959X
• DOI: 10.3174/ajnr.a2385

Currently it is difficult to predict tumor response to anti-angiogenic therapy in individual patients. Our aim was to determine if ADC histogram analysis can stratify progression-free and overall survival in patients with newly diagnosed GBM treated "up-front" (ie, before tumor recurrence) with bevacizumab. Up-front bevacizumab-treated and control patients (n = 59 and 62, respectively) with newly diagnosed GBM were analyzed by using an ADC histogram approach based on enhancing tumor. Progression-free and overall survival was determined by using Cox proportional HRs and the Kaplan-Meier method with logrank and Wilcoxon tests. For up-front bevacizumab-treated patients, lower ADC(L) was associated with significantly longer progression-free survival (median, 459 days for ADC(L) < 1200 versus 315 days for ADC(L) ≥ 1200 10(-6)mm(2)/s; P = .008, logrank test) and trended with longer overall survival (581 versus 429 days, P = .055). ADC values did not stratify progression-free or overall survival for patients in the control group (P = .92 and P = .22, respectively). Tumors with MGMT promoter methylation had lower ADC(L) values than unmethylated tumors (mean, 1071 versus 1183 10(-6)mm(2)/s; P = .01, 2-group t test). Pretreatment ADC histogram analysis can stratify progression-free survival in bevacizumab-treated patients with newly diagnosed GBM. Lower ADC is associated with tumor MGMT promoter methylation, which may, in part, account for the favorable outcome associated with low ADC(L) tumors.