title: Impact of radiotherapy delay on survival in glioblastoma.
abstract: BACKGROUND
  Previous studies in glioblastoma have concluded that there is no decrease in survival with increasing time to initiation of RT up to 6 weeks after surgery. Unfortunately, the number of glioblastoma patients who start RT beyond 6 weeks is not small in some countries. The aim of our study was to evaluate the effect of RT delay beyond 6 weeks on survival of patients who have undergone completed resection of a glioblastoma.
  
  
  METHODS
  We reviewed 107 consecutive glioblastoma patients who had a complete surgical resection at our hospital. Clinical data, including delay in initiation of RT, were prospectively collected. The impact of single parameters on overall survival was determined by univariate and multivariate analyses.
  
  
  RESULTS
  According to univariate analysis, variables that had a prognostic influence on survival were age (p = 0.036), KPS (p = 0.031), additional treatment with CHT (p < 0.0001), and initiation of RT before 42 days (p = 0.009). Multivariate analysis indicated that Karnofsky performance scale, additional treatment with chemotherapy, and initiation of RT before 6 weeks after surgery were favorable, independent prognostic factors of survival.
  
  
  CONCLUSIONS
  Survival is significantly reduced in glioblastoma patients if RT is not initiated within the 6 weeks after complete resection of the tumor.
authors.affiliation: Radiation Oncology Service, Institute of Haematology and Oncology, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Villarroel 170, 08036 Barcelona, Spain. ivalduvi@clinic.ub.es
authors.forename: Izaskun
authors.initials: I
authors.lastname: Valduvieco
authors.forename: Eugènia
authors.initials: E
authors.lastname: Verger
authors.forename: Jordi
authors.initials: J
authors.lastname: Bruna
authors.forename: Lluís
authors.initials: L
authors.lastname: Caral
authors.forename: Teresa
authors.initials: T
authors.lastname: Pujol
authors.forename: Teresa
authors.initials: T
authors.lastname: Ribalta
authors.forename: Teresa
authors.initials: T
authors.lastname: Boget
authors.forename: Laura
authors.initials: L
authors.lastname: Oleaga
authors.forename: Estela
authors.initials: E
authors.lastname: Pineda
authors.forename: Francesc
authors.initials: F
authors.lastname: Graus
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000175:diagnosis / Q000401:mortality* / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis / Q000401:mortality* / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult