title: Chemopotentiation by ultrafractionated radiotherapy in glioblastoma resistant to conventional therapy.
abstract: BACKGROUND
  Induced radiation resistance (IRR) and hyper-radiosensitivity (HRS) are well-described phenomena in basic literature, yet few reports have been published in which such phenomena are exploited clinically for the benefit of patients. Glioblastoma is a prime example.
  
  
  METHODS
  The case of an 82-year-old woman is described whose resected frontoparietal glioblastoma progressed through treatment administered according to standard methods. With review board and patient approval, we continued her treatment using radiotherapy and temozolomide, but drastically modified the radiotherapy fractionation, administering 50 cGy twice daily on each of the first 5 days of a 14-day cycle. Temozolomide was administered on the first 4 days of each cycle. We use the term "ultrafractionated radiotherapy" to refer to the extremely low doses of radiation used in this case.
  
  
  RESULTS
  This modified regimen resulted in regression of the contrast-enhancing areas of disease recurrence identified on MRI, and the patient survived approximately 6 months following recurrence of her disease, having received 5 cycles of additional therapy after prior full-dose treatment.
  
  
  CONCLUSIONS
  Ultrafractionated radiotherapy and concurrent temozolomide were efficacious and tolerable in this patient whose glioblastoma previously progressed through conventional treatment. Additional studies of this approach are warranted.
authors.affiliation: Assurance Oncology Services, LLC, 70 Bowden Circle, Chelsea, AL 35043, USA. chris@assuranceonc.com
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Jahraus
authors.forename: Allan H
authors.initials: AH
authors.lastname: Friedman
mesh_terms: D000369:Aged, 80 and over; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D003606:Dacarbazine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D018450:Disease Progression; D019583:Dose Fractionation, Radiation; D005260:Female; D005625:Frontal Lobe / Q000473:pathology / Q000601:surgery; D005909:Glioblastoma / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000532:radiotherapy*; D000077204:Temozolomide; D013702:Temporal Lobe / Q000473:pathology / Q000601:surgery; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D018906:Antineoplastic Agents, Alkylating; D003606:Dacarbazine; D000077204:Temozolomide