Study protocol: PreOperative Brain Irradiation in Glioblastoma (POBIG) – A phase I trial. (March 2023)

• Record Type: Journal Article
• Authors: Waqar, Mueez; Roncaroli, Federico; Djoukhadar, Ibrahim; Akkari, Leila; O'Leary, Claire; Hewitt, Lauren; Forte, Gabriella; Jackson, Richard; Hessen, Eline; Withington, Lisa; Beasley, William; Richardson, Jenny; Golby, Christopher; Whitehurst, Philip; Colaco, Rovel; Bailey, Matthew; Karabatsou, Konstantina; D'Urso, Pietro I.; McBain, Catherine; Coope, David J.; Borst, Gerben R.
• Is Part Of: Clinical and translational radiation oncology. Volume 39(2023)
• Publication Date: 2023-03
• Subjects: Glioblastoma -- Trial -- Preoperative -- Neoadjuvant -- Radiotherapy -- Dose escalation -- POBIG -- Hypofractionated; Cancer -- Radiotherapy -- Periodicals; Oncology -- Periodicals; Cancer -- Radiotherapy; Oncology; Radiation Oncology; Neoplasms -- radiotherapy; Translational Medical Research; Periodicals; Electronic journals; Periodicals; 616.9940642
• DOI: 10.1016/j.ctro.2023.100585
• Languages: English
• ISSNs: 2405-6308

Abstract

Highlights: POBIG is a phase I dose escalation trial of preop radiotherapy for glioblastoma. First trial of its kind for newly-diagnosed glioblastoma. Patient inclusion is dependent on imaging diagnosis. For diagnosis, part of the tumour is unirradiated (cold spot) Tumour at risk of remaining as postop residuum will be irradiated (hot spot) Abstract: Background: Glioblastoma is a high-grade aggressive neoplasm whose outcomes have not changed in decades. In the current treatment pathway, tumour growth continues and remains untreated for several weeks post-diagnosis. Intensified upfront therapy could target otherwise untreated tumour cells and improve the treatment outcome. POBIG will evaluate the safety and feasibility of single-fraction preoperative radiotherapy for newly diagnosed glioblastoma, assessed by the maximum tolerated dose (MTD) and maximum tolerated irradiation volume (MTIV). Methods: POBIG is an open-label, dual-centre phase I dose and volume escalation trial that has received ethical approval. Patients with a new radiological diagnosis of glioblastoma will be screened for eligibility. This is deemed sufficient due to the high accuracy of imaging and to avoid treatment delay. Eligible patients will receive a single fraction of preoperative radiotherapy ranging from 6 to 14 Gy followed by their standard of care treatment comprising maximal safe resection and postoperative chemoradiotherapy (60 Gy/30 fr) with concurrent and adjuvant temozolomide). Preoperative radiotherapy will be directed to the part of the tumour that is highest risk for remaining as postoperative residual disease (hot spot). Part of the tumour will remain unirradiated (cold spot) and sampled separately for diagnostic purposes. Dose/volume escalation will be guided by a Continual Reassessment Method (CRM) model. Translational opportunities will be afforded through comparison of irradiated and unirradiated primary glioblastoma tissue. Discussion: POBIG will help establish the role of radiotherapy in preoperative modalities for glioblastoma. Trial registration: NCT03582514 (clinicaltrials.gov ).