title: Quantitative MR perfusion parameters related to survival time in high-grade gliomas.
abstract: OBJECTIVE
  To evaluate the quantitative parameters obtained from dynamic MR T2*-weighted images as predictors of survival taking into consideration the biasing effects of other survival-related covariates.
  
  
  METHODS
  Thirty-nine patients (60 ± 14 years; survival 267 ± 191 days) with high-grade gliomas (8 grade III, 31 grade IV) were retrospectively included in the study. Additional data incorporated Karnofsky performance scale, tumour resection extension after surgery and type of treatment. Dynamic T2*-weighted MRI was acquired before treatment. Tumour curves were extracted for each voxel, and several quantitative parameters were obtained from the whole tumour volume and the 10 % maximum values. Additional image covariates included the presence of necrosis, single or multiple lesions, and tumour and oedema volumes. The relationship between quantitative parameters and survival was assessed using clusterisation techniques and the log-rank method. Cox regression analysis was used to evaluate each parameter's predictive value.
  
  
  RESULTS
  Only the mean of the 10 % maximum values of the transfer coefficient showed an independent relationship with patient survival (log-rank chi-squared test <0.001, Cox regression P = 0.015), with higher values corresponding to lower survival rates.
  
  
  CONCLUSIONS
  High maximum transfer coefficient values show an independent statistical relationship with low survival in high-grade glioma patients. This imaging biomarker can be used as a predictor of prognosis.
authors.affiliation: Radiology Department, Hospital Quirón Valencia, Av Blasco Ibañez 14, 46010, Valencia, Spain, rsanz.val@quiron.es.
authors.forename: Roberto
authors.initials: R
authors.lastname: Sanz-Requena
authors.forename: Antonio
authors.initials: A
authors.lastname: Revert-Ventura
authors.forename: Luis
authors.initials: L
authors.lastname: Martí-Bonmatí
authors.forename: Angel
authors.initials: A
authors.lastname: Alberich-Bayarri
authors.forename: Gracián
authors.initials: G
authors.lastname: García-Martí
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000401:mortality* / Q000473:pathology*; D005069:Evaluation Studies as Topic; D005260:Female; D005910:Glioma / Q000401:mortality* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate