title: Establishing percent resection and residual volume thresholds affecting survival and recurrence for patients with newly diagnosed intracranial glioblastoma.
abstract: BACKGROUND
  Surgery is first-line therapy for glioblastoma, and there is evidence that gross total resection is associated with improved survival. Gross total resection, however, is not always possible, and relationships among extent (percent) of resection (EOR), residual volume (RV), and survival are unknown. The goals were to evaluate whether there is an association between EOR and RV with survival and recurrence and to establish minimum EOR and maximum RV thresholds.
  
  
  METHODS
  Adult patients who underwent primary glioblastoma surgery from 2007 to 2011 were retrospectively reviewed. Three-dimensional volumetric tumor measurements were made. Multivariate proportional hazards regression analysis was used to evaluate the relationship between EOR and RV with survival and recurrence.
  
  
  RESULTS
  Of 259 patients, 203 (78%) died and 156 (60%) had tumor recurrence. The median survival and progression-free survival were 13.4 and 8.9 months, respectively. The median (interquartile range) pre- and postoperative tumor volumes were 32.2 (14.0-56.3) and 2.1 (0.0-7.9) cm(3), respectively. EOR was independently associated with survival (hazard ratio [HR], 0.995; 95% confidence interval [CI]: 0.990-0.998; P = .008) and recurrence (HR [95% CI], 0.992 [0.983-0.998], P = .005). The minimum EOR threshold for survival (P = .0006) and recurrence (P = .005) was 70%. RV was also associated with survival (HR [95% CI], 1.019 [1.006-1.030], P = .004) and recurrence (HR [95% CI], 1.024 [1.001-1.044], P = .03). The maximum RV threshold for survival (P = .01) and recurrence (P = .01) was 5 cm(3).
  
  
  CONCLUSIONS
  This study shows for the first time that both EOR and RV are significantly associated with survival and recurrence, where the thresholds are 70% and 5 cm(3), respectively. These findings may help guide surgical and adjuvant therapies aimed at optimizing outcomes for glioblastoma patients.
authors.affiliation: Corresponding authors: Kaisorn L. Chaichana, MD, The Johns Hopkins Hospital, Department of Neurosurgery, Johns Hopkins University, 600 North Wolfe Street, Meyer 8-184, Baltimore, MD 21202. kaisorn@jhmi.edu); Alfredo Quiñones-Hinojosa, MD, The Johns Hopkins Hospital, Department of Neurosurgery, Johns Hopkins University, Cancer Research Building II, 1550 Orleans Street, Room 247, Baltimore, MD 21231 (aquinon2@jhmi.edu.
authors.forename: Kaisorn L
authors.initials: KL
authors.lastname: Chaichana
authors.forename: Ignacio
authors.initials: I
authors.lastname: Jusue-Torres
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Navarro-Ramirez
authors.forename: Shaan M
authors.initials: SM
authors.lastname: Raza
authors.forename: Maria
authors.initials: M
authors.lastname: Pascual-Gallego
authors.forename: Aly
authors.initials: A
authors.lastname: Ibrahim
authors.forename: Marta
authors.initials: M
authors.lastname: Hernandez-Hermann
authors.forename: Luis
authors.initials: L
authors.lastname: Gomez
authors.forename: Xiaobu
authors.initials: X
authors.lastname: Ye
authors.forename: Jon D
authors.initials: JD
authors.lastname: Weingart
authors.forename: Alessandro
authors.initials: A
authors.lastname: Olivi
authors.forename: Jaishri
authors.initials: J
authors.lastname: Blakeley
authors.forename: Gary L
authors.initials: GL
authors.lastname: Gallia
authors.forename: Michael
authors.initials: M
authors.lastname: Lim
authors.forename: Henry
authors.initials: H
authors.lastname: Brem
authors.forename: Alfredo
authors.initials: A
authors.lastname: Quinones-Hinojosa
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005909:Glioblastoma / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000209:etiology / Q000401:mortality*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000175:diagnosis / Q000209:etiology / Q000401:mortality*; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D047368:Tumor Burden; D055815:Young Adult
keywords: GBM; extent of resection; glioblastoma; residual; surgery; survival; volumetric