title: Patterns and timing of recurrence after temozolomide-based chemoradiation for glioblastoma.
abstract: OBJECTIVE
  To determine recurrence patterns of glioblastoma treated with temozolomide-based chemoradiation.
  
  
  METHODS
  Pretreatment and serial posttreatment magnetic resonance imaging scans of 54 patients were retrospectively evaluated. Central recurrence (i.e., local progression) and the development of new (i.e., interval appearance of discrete enhancing lesion) in-field, marginal, and distant recurrences were assessed, with the pattern of recurrence of individual lesions defined relative to the 95% isodose line (D(95)). Distant recurrences were defined as lesions completely outside D(95), marginal recurrences crossed D(95), and in-field recurrences were completely inside D(95).
  
  
  RESULTS
  At a median follow-up of 17 months, 39 of 54 (72%) patients developed recurrent glioblastoma. Among these 39 patients, central recurrence occurred in 80% (at a median of 7 months from diagnosis); new in-field recurrence developed in 33% (at a median of 14 months); marginal recurrences developed in 15% (at a median of 18 months); and distant recurrences developed in 20% (at a median of 11 months). The actuarial rates of central, new in-field, marginal, distant, and any new recurrences at 1-year were 46%, 15%, 3%, 14%, and 25% respectively, whereas at 2 years, the rates were 68%, 60%, 32%, 28%, and 66%, reflecting an increasing probability of new lesions developing at later time points. Ten patients developed subependymal recurrences, of whom 7 developed multiple subependymal lesions.
  
  
  CONCLUSIONS
  Whereas central recurrence of glioblastoma treated with radiation and temozolomide predominates and persists over time, new in-field, marginal, and distant recurrences commonly develop, particularly at later time points in patients with longer survival.
authors.affiliation: Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA. MTMilano@yahoo.com
authors.forename: Michael T
authors.initials: MT
authors.lastname: Milano
authors.forename: Paul
authors.initials: P
authors.lastname: Okunieff
authors.forename: Rosemary S
authors.initials: RS
authors.lastname: Donatello
authors.forename: Nimish A
authors.initials: NA
authors.lastname: Mohile
authors.forename: Joohee
authors.initials: J
authors.lastname: Sul
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Walter
authors.forename: David N
authors.initials: DN
authors.lastname: Korones
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D003131:Combined Modality Therapy / Q000379:methods; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy / Q000532:radiotherapy / Q000556:secondary; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D000077204:Temozolomide; D013997:Time Factors
chemical_list: D018906:Antineoplastic Agents, Alkylating; D003606:Dacarbazine; D000077204:Temozolomide