Glioma consensus contouring recommendations from a MR-Linac International Consortium Research Group and evaluation of a CT-MRI and MRI-only workflow

J Neurooncol. 2020 Sep;149(2):305-314. doi: 10.1007/s11060-020-03605-6. Epub 2020 Aug 29.


Introduction: This study proposes contouring recommendations for radiation treatment planning target volumes and organs-at-risk (OARs) for both low grade and high grade gliomas.

Methods: Ten cases consisting of 5 glioblastomas and 5 grade II or III gliomas, including their respective gross tumor volume (GTV), clinical target volume (CTV), and OARs were each contoured by 6 experienced neuro-radiation oncologists from 5 international institutions. Each case was first contoured using only MRI sequences (MRI-only), and then re-contoured with the addition of a fused planning CT (CT-MRI). The level of agreement among all contours was assessed using simultaneous truth and performance level estimation (STAPLE) with the kappa statistic and Dice similarity coefficient.

Results: A high level of agreement was observed between the GTV and CTV contours in the MRI-only workflow with a mean kappa of 0.88 and 0.89, respectively, with no statistically significant differences compared to the CT-MRI workflow (p = 0.88 and p = 0.82 for GTV and CTV, respectively). Agreement in cochlea contours improved from a mean kappa of 0.39 to 0.41, to 0.69 to 0.71 with the addition of CT information (p < 0.0001 for both cochleae). Substantial to near perfect level of agreement was observed in all other contoured OARs with a mean kappa range of 0.60 to 0.90 in both MRI-only and CT-MRI workflows.

Conclusions: Consensus contouring recommendations for low grade and high grade gliomas were established using the results from the consensus STAPLE contours, which will serve as a basis for further study and clinical trials by the MR-Linac Consortium.

Keywords: Consensus contouring recommendations; Glioma; MR-linac; Organs-at-risk; Radiotherapy.

MeSH terms

  • Brachytherapy
  • Consensus
  • Follow-Up Studies
  • Glioblastoma / diagnostic imaging*
  • Glioblastoma / pathology*
  • Glioblastoma / radiotherapy
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Particle Accelerators
  • Practice Guidelines as Topic / standards*
  • Practice Patterns, Physicians' / standards*
  • Prognosis
  • Prospective Studies
  • Radiotherapy Planning, Computer-Assisted / methods*
  • Retrospective Studies
  • Tomography, X-Ray Computed / methods*
  • Tumor Burden
  • Workflow