title: Validation of an established prognostic score after re-irradiation of recurrent glioma.
abstract: BACKGROUND
  Re-irradiation (Re-RT) is offered widely in clinical routine, and has been established as a key element in the treatment of recurrent gliomas. At our center, generally re-resection is performed widely by an experienced neurosurgical team. Thus, Re-RT mostly offered to patients with macroscopic residuals or irresectable lesions, is applied later compared to other centers. Therefore, we sought to validate the Combs Prognostic Score developed in 2012 using our independent patient cohort.
  
  
  METHODS
  We included 199 patients treated from 2002 until April 2016 for recurrent glioma at the Department of Radiation Oncology at the Klinikum Rechts der Isar, Munich. Different concepts of Re-RT were applied.
  
  
  RESULTS
  Median follow-up after Re-RT was 2.5 months. Median overall survival (OS) after Re-RT was 7.9 months for WHO IV gliomas, 11.3 months for WHO III gliomas, and 13.6 months for low-grade gliomas (WHO I/II). Univariate analyses confirmed the prognostic factors primary histology (p = 0.001), age (p = 0.002), and time between primary radiotherapy and Re-RT (p < 0.001). We also tested Karnofsky Performance Score (KPS), gender, and neurological symptoms before Re-RT as well as planning target volume and found only KPS also significant at p < 0.001. Comparing the prognostic score groups, the outcome was highly statistically significant at p < 0.001.
  
  
  CONCLUSIONS
  In our analysis, we validated the Combs Prognostic Score. Validation in this independent large patient cohort confirms the significance of the score for glioma recurrences. Thus, the role of the Combs Prognostic Score might be an essential component of future clinical decision making and patient stratification.
authors.affiliation: a Department of Radiation Oncology , Technische Universität München (TUM) , Munich , Germany.|b Department of Radiation Sciences (DRS) , Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München , Neuherberg , Germany.
authors.forename: Kerstin A
authors.initials: KA
authors.lastname: Kessel
authors.affiliation: a Department of Radiation Oncology , Technische Universität München (TUM) , Munich , Germany.
authors.forename: Josefine
authors.initials: J
authors.lastname: Hesse
authors.affiliation: a Department of Radiation Oncology , Technische Universität München (TUM) , Munich , Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Straube
authors.affiliation: c Department of Neuroradiology , Technical University of Munich , Munich , Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Zimmer
authors.affiliation: d Department of Neurology , Technical University of Munich , Munich , Germany.
authors.forename: Friederike
authors.initials: F
authors.lastname: Schmidt-Graf
authors.affiliation: e Department of Neuropathology , Technical University of Munich , Munich , Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schlegel
authors.affiliation: f Department of Neurosurgery , Technical University of Munich , Munich , Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Meyer
authors.affiliation: a Department of Radiation Oncology , Technische Universität München (TUM) , Munich , Germany.|b Department of Radiation Sciences (DRS) , Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München , Neuherberg , Germany.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Combs
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy*; D015331:Cohort Studies; D003657:Decision Making; D005260:Female; D005910:Glioma / Q000175:diagnosis* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D017567:Karnofsky Performance Status; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000532:radiotherapy*; D011379:Prognosis; D000069475:Re-Irradiation; D012107:Research Design; D016019:Survival Analysis