title: Glioblastoma treated with postoperative radio-chemotherapy: prognostic value of apparent diffusion coefficient at MR imaging.
abstract: OBJECTIVE
  To retrospectively evaluate whether the mean, minimum, and maximum apparent diffusion coefficient (ADC) of glioblastomas obtained from pretreatment MR images is of prognostic value in patients with glioblastoma.
  
  
  METHODS
  The institutional review board approved our study and waived the requirement for informed patient consent. Between February 1998 and January 2006, 33 patients (24 males, 9 females; age range 10-76 years) with supratentorial glioblastoma underwent pretreatment magnetic resonance (MR) imaging. The values of the mean, minimum, and maximum ADC (ADC(mean), ADC(MIN), and ADC(MAX), respectively) of each tumor were preoperatively determined from several regions of interest defined in the tumors. After surgical intervention, all patients underwent irradiation and chemotherapy performed according to our hospital protocol. The patient age, symptom duration, Karnofsky performance scale score, extent of surgery, and ADC were assessed using factor analysis of overall survival. Prognostic factors were evaluated using Kaplan-Meier survival curves, the log-rank test, and multiple regression analysis with the Cox proportional hazards model.
  
  
  RESULTS
  Likelihood ratio tests confirmed that ADC(MIN) was the strongest among the three prognostic factors. Total surgical removal was the most important predictive factor for overall survival (P<0.01). ADC(MIN) was also statistically correlated with overall survival (P<0.05) and could be used to classify patients into different prognostic groups. Interestingly, ADC(MIN) was also the strongest prognostic factor (P<0.01) in the group of patients in whom total tumor removal was not possible.
  
  
  CONCLUSIONS
  The ADC(MIN) value obtained from pretreatment MR images is a useful clinical prognostic biomarker in patients with glioblastoma.
authors.affiliation: Department of Neurosurgery, Graduate School of Biomedical Sciences, Hiroshima University, Minami-ku, Hiroshima 734-8551, Japan.
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Yamasaki
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Megu
authors.initials: M
authors.lastname: Ohtaki
authors.forename: Yukio
authors.initials: Y
authors.lastname: Takeshima
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Abe
authors.forename: Yuji
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Junko
authors.initials: J
authors.lastname: Takaba
authors.forename: Vishwa Jeet
authors.initials: VJ
authors.lastname: Amatya
authors.forename: Taiichi
authors.initials: T
authors.lastname: Saito
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kajiwara
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Hanaya
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kurisu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003131:Combined Modality Therapy; D003287:Contrast Media; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D011859:Radiography; D012189:Retrospective Studies; D015173:Supratentorial Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000601:surgery; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media