A phase i dose escalation study of hypofractionated IMRT field-in-field boost for newly diagnosed glioblastoma multiforme

Arta M Monjazeb, Deandra Ayala, Courtney Jensen, L. Douglas Case, J. Daniel Bourland, Thomas L. Ellis, Kevin P. McMullen, Michael D. Chan, Stephen B. Tatter, Glen J. Lesser, Edward G. Shaw

Research output: Contribution to journalArticle

21 Scopus citations


Objectives: To describe the results of a Phase I dose escalation trial for newly diagnosed glioblastoma multiforme (GBM) using a hypofractionated concurrent intensity-modulated radiotherapy (IMRT) boost. Methods: Twenty-one patients were enrolled between April 1999 and August 2003. Radiotherapy consisted of daily fractions of 1.8 Gy with a concurrent boost of 0.7 Gy (total 2.5 Gy daily) to a total dose of 70, 75, or 80 Gy. Concurrent chemotherapy was not permitted. Seven patients were enrolled at each dose and dose limiting toxicities were defined as irreversible Grade 3 or any Grade 4-5 acute neurotoxicity attributable to radiotherapy. Results: All patients experienced Grade 1 or 2 acute toxicities. Acutely, 8 patients experienced Grade 3 and 1 patient experienced Grade 3 and 4 toxicities. Of these, only two reversible cases of otitis media were attributable to radiotherapy. No dose-limiting toxicities were encountered. Only 2 patients experienced Grade 3 delayed toxicity and there was no delayed Grade 4 toxicity. Eleven patients requiring repeat resection or biopsy were found to have viable tumor and radiation changes with no cases of radionecrosis alone. Median overall and progression-free survival for this cohort were 13.6 and 6.5 months, respectively. One- and 2-year survival rates were 57% and 19%. At recurrence, 15 patients received chemotherapy, 9 underwent resection, and 5 received radiotherapy. Conclusions: Using a hypofractionated concurrent IMRT boost, we were able to safely treat patients to 80 Gy without any dose-limiting toxicity. Given that local failure still remains the predominant pattern for GBM patients, a trial of dose escalation with IMRT and temozolomide is warranted.

Original languageEnglish (US)
Pages (from-to)743-748
Number of pages6
JournalInternational Journal of Radiation Oncology Biology Physics
Issue number2
StatePublished - Feb 1 2012



  • Dose escalation
  • Glioblastoma Multiforme
  • IMRT
  • Radiotherapy
  • Temozolomide

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Radiation
  • Cancer Research

Cite this

Monjazeb, A. M., Ayala, D., Jensen, C., Case, L. D., Bourland, J. D., Ellis, T. L., McMullen, K. P., Chan, M. D., Tatter, S. B., Lesser, G. J., & Shaw, E. G. (2012). A phase i dose escalation study of hypofractionated IMRT field-in-field boost for newly diagnosed glioblastoma multiforme. International Journal of Radiation Oncology Biology Physics, 82(2), 743-748. https://doi.org/10.1016/j.ijrobp.2010.10.018