Comparison of radiation regimens in the treatment of Glioblastoma multiforme: results from a single institution.
BACKGROUND
The optimal fractionation schedule of radiotherapy (RT) for Glioblastoma multiforme (GBM) is yet to be determined. We aim to compare different fractionation regimens and identify prognostic factors to better tailor RT for newly diagnosed GBM patients.


METHODS
All data for patients who underwent surgery for GBM between January 2005 and December 2012 were compiled. Clinical information was collected using patient charts and government registry. Cox analysis was used to identify variables affecting survival and treatment outcome.


RESULTS
The median follow-up time was 13.2 months. Two hundred and seventy-six patients met the inclusion criteria, including 147 patients in the 60 Gy in 30 fractions (ConvRT) group, 86 patients in the 60 Gy in 20 fractions (HF60) group, and 43 patients in the 40 Gy in 15 fractions (HF40) group. Median survival (MS) was 16.0 months with a median progression-free survival (PFS) of 9.23 months in the ConvRT group. This was comparable to outcome in the HF60 group with MS 15.0 months and a median PFS of 9.1 months. Patients in the HF40 group had MS of 8 months, with a median PFS 5.4 months. Cox analysis showed no significant difference in OS between the ConvRT and HF60 groups but worse outcome in the HF40 group (HR 2.22, P=0.04). MGMT methylation, extent of resection, use of chemotherapy, and repeat surgery were found to be significant independent prognostic factors for survival.


CONCLUSIONS
HF60 constitutes a safe RT approach that shows survival comparable to standard RT while allowing for a shorter treatment time.
Department of Oncology, Division of Radiation Oncology, McGill University, Montreal General Hospital, 1650 Avenue Cedar, H3G 1A4, Montréal, QC, Canada. melissa.azoulay@mail.mcgill.ca.
Melissa
M
Azoulay
Department of Oncology, Division of Cancer Epidemiology, McGill University, 546 Pine Avenue West, H2W1S6, Montreal, QC, Canada. fabiano.santos@mcgill.ca.
Fabiano
F
Santos
Department of Oncology, Division of Radiation Oncology, McGill University, Montreal General Hospital, 1650 Avenue Cedar, H3G 1A4, Montréal, QC, Canada. luis.souhami@mcgill.ca.
Luis
L
Souhami
Department of Oncology, Division of Radiation Oncology, McGill University, Montreal General Hospital, 1650 Avenue Cedar, H3G 1A4, Montréal, QC, Canada. valerie.panet-raymond@mcgill.ca.
Valerie
V
Panet-Raymond
Department of Neurology and Neurosurgery, Montreal Neurological Hospital, McGill University, 3801 University Avenue, H2W1S6, Montreal, QC, Canada. kevin.petrecca@mcgill.ca.
Kevin
K
Petrecca
Division of Medical oncology, Department of Oncology, Montreal General Hospital, McGill University, 1650 Avenue Cedar, H3G 1A4, Montréal, QC, Canada. scott.owen@mcgill.ca.
Scott
S
Owen
Department of Pathology, Montreal Neurological Hospital, McGill University, 3801 University Avenue, H3A 2B4, Montreal, QC, Canada. marie.christine.guiot@mcgill.ca.
Marie-Christine
MC
Guiot
Research Institute of the McGill University Health Center, Montreal General Hospital, 1625 Pine Avenue West, H3G 1A4, Montreal, QC, Canada. mariia.patyka@mail.mcgill.ca.
Mariia
M
Patyka
Department of Oncology, Division of Radiation Oncology, McGill University, Montreal General Hospital, 1650 Avenue Cedar, H3G 1A4, Montréal, QC, Canada. siham.sabri@mcgill.ca.|Research Institute of the McGill University Health Center, Montreal General Hospital, 1625 Pine Avenue West, H3G 1A4, Montreal, QC, Canada. siham.sabri@mcgill.ca.
Siham
S
Sabri
Department of Oncology, Division of Radiation Oncology, McGill University, Montreal General Hospital, 1650 Avenue Cedar, H3G 1A4, Montréal, QC, Canada. george.shenouda@mcgill.ca.
George
G
Shenouda
Department of Oncology, Division of Radiation Oncology, McGill University, Montreal General Hospital, 1650 Avenue Cedar, H3G 1A4, Montréal, QC, Canada. bassam.abdulkarim@mcgill.ca.
Bassam
B
Abdulkarim
D000368:Aged; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use; D001918:Brachytherapy / Q000401:mortality*; D001932:Brain Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D059248:Chemoradiotherapy / Q000401:mortality*; D003606:Dacarbazine / Q000031:analogs & derivatives / Q000627:therapeutic use; D019583:Dose Fractionation, Radiation; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D011379:Prognosis; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D015996:Survival Rate; D000077204:Temozolomide
D018906:Antineoplastic Agents, Alkylating; D003606:Dacarbazine; D000077204:Temozolomide