Surgery to resect the GB using Diffusion Tensor Imaging (DTI) and intraoperative Ultrasound (iUS) (navigated iUS where available) in addition to standard care (i.e. neuronavigation based on preoperative MRI and intraoperative use of 5-aminolevulinic acid (5-ALA))

The comparator is standard care as per current NICE guidelines (i.e. neuronavigation based on preoperative MRI and intraoperative use of 5-ALA).

Neuronavigation and intraoperative 5-ALA

Sites are qualitatively assessed through a standardisation stage, providing feedback to enable learning and ensure the workflow is followed. Sites with satisfactory data will "progress" and pass into Stage 2.

The measures assessed in combination are:

1. Operation length, in normal range for this surgery.
2. Use of DTI neuronavigation & iUS to achieve maximal safe tumour resection without major neurological deficit, measured by getting clear, relevant images for the DTI & US scans, and accurate pre-operative tractography.
3. Extent of tumour resection (cm³ remaining) on postoperative MRI scan.
4. Surgical Complications/Serious Adverse Events-measured from recorded post-operative complications and a 6-month notes check to ensure patient safety.

If the assessment panel is satisfied with the data after ~3 recruits, a site will progress into Stage 2 of the trial, the RCT. Data will be analysed for Stage 1 once all sites have progressed through into Stage 2 of the trial.

This is measured by a composite of:

1. Change in global health status domain of the QLQ-C30 questionnaire (Quality of Life Questionnaire Cancer) from baseline to final questionnaire completion. Questionnaires are administered at baseline, 6 weeks, then every 3 months until 24months.
2. Progression Free Survival (PFS). This is measured by radiological tumour progression on imaging, which is taken 3-months post-op and 3-monthly thereafter.
3. Overall Survival (OS) with an event defined as either deterioration, progression or death.

This is measured using a combination of specific questions (physical functioning and social functioning) in the QLQ-C30 (Quality of Life Questionnaire Cancer) and BN20 questionnaire (Quality of Life Questionnaire Brain) (motor dysfunction and communication deficit questions), combined with the values of Progression Free Survival (PFS) and overall survival (OS) taken from the primary outcome.

Questionnaires are administered at baseline, 6 weeks, then every 3 months until 24months.

To assess the sensitivity and specificity of the anatomico-spatial location of DTI fibre tracts compared with intraoperative direct electrical stimulation/behavioural change without stimulation but related to adjacent white fibre tract in patients undergoing awake surgery, or motor evoked potential changes in patients undergoing surgery.

Measured by sensitivity and specificity calculation using pre and post-surgery MRI images