title: Phase I study of hypofractionated intensity modulated radiation therapy with concurrent and adjuvant temozolomide in patients with glioblastoma multiforme.
abstract: OBJECTIVE
  To determine the safety and efficacy of hypofractionated intensity modulated radiation therapy (Hypo-IMRT) using helical tomotherapy (HT) with concurrent low dose temozolomide (TMZ) followed by adjuvant TMZ in patients with glioblastoma multiforme (GBM).
  
  
  METHODS
  Adult patients with GBM and KPS > 70 were prospectively enrolled between 2005 and 2007 in this phase I study. The Fibonacci dose escalation protocol was implemented to establish a safe radiation fractionation regimen. The protocol defined radiation therapy (RT) dose level I as 54.4 Gy in 20 fractions over 4 weeks and dose level II as 60 Gy in 22 fractions over 4.5 weeks. Concurrent TMZ followed by adjuvant TMZ was given according to the Stupp regimen. The primary endpoints were feasibility and safety of Hypo-IMRT with concurrent TMZ. Secondary endpoints included progression free survival (PFS), pattern of failure, overall survival (OS) and incidence of pseudoprogression. The latter was defined as clinical or radiological suggestion of tumour progression within three months of radiation completion followed by spontaneous recovery of the patient.
  
  
  RESULTS
  A total of 25 patients were prospectively enrolled with a median follow-up of 12.4 months. The median age at diagnosis was 53 years. Based on recursive partitioning analysis (RPA) criteria, 16%, 52% and 32% of the patients were RPA class III, class IV and class V, respectively. All patients completed concurrent RT and TMZ, and 19 patients (76.0%) received adjuvant TMZ. The median OS was 15.67 months (95% CI 11.56 - 20.04) and the median PFS was 6.7 months (95% CI 4.0 - 14.0). The median time between surgery and start of RT was 44 days (range of 28 to 77 days). Delaying radiation therapy by more than 6 weeks after surgery was an independent prognostic factor associated with a worse OS (4.0 vs. 16.1 months, P = 0.027). All recurrences occurred within 2 cm of the original gross tumour volume (GTV). No cases of pseudoprogression were identified in our cohort of patients. Three patients tolerated dose level I with no dose limiting toxicity and hence the remainder of the patients were treated with dose level II according to the dose escalation protocol. Grade 3-4 hematological toxicity was limited to two patients and one patient developed Grade 4 Pneumocystis jiroveci pneumonia.
  
  
  CONCLUSIONS
  Hypo-IMRT using HT given with concurrent TMZ is feasible and safe. The median OS and PFS are comparable to those observed with conventional fractionation. Hypofractionated radiation therapy offers the advantage of a shorter treatment period which is imperative in this group of patients with limited life expectancy.
authors: Division of Radiation Oncology, Cross Cancer Institute and University of Alberta, 11560, University Avenue, Edmonton, AB, T6G 1Z2, Canada.
authors: Noha
authors: N
authors: Jastaniyah
authors: Albert
authors: A
authors: Murtha
authors: Nadeem
authors: N
authors: Pervez
authors: Duc
authors: D
authors: Le
authors: Wilson
authors: W
authors: Roa
authors: Samir
authors: S
authors: Patel
authors: Marc
authors: M
authors: Mackenzie
authors: Dorcas
authors: D
authors: Fulton
authors: Colin
authors: C
authors: Field
authors: Sunita
authors: S
authors: Ghosh
authors: Gino
authors: G
authors: Fallone
authors: Bassam
authors: B
authors: Abdulkarim
mesh_terms: D000328:Adult; D000368:Aged; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use*; D001918:Brachytherapy; D001932:Brain Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D017024:Chemotherapy, Adjuvant; D003606:Dacarbazine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D005909:Glioblastoma / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000628:therapy; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal; D050397:Radiotherapy, Intensity-Modulated; D015996:Survival Rate; D000077204:Temozolomide; D055815:Young Adult
chemical_list: D018906:Antineoplastic Agents, Alkylating; D003606:Dacarbazine; D000077204:Temozolomide