Imaging

Scottish Cancer Network: Clinical Management Pathways
NHS National Services Scotland
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This consensus document is not a rigid constraint on clinical practice, but a concept of good practice against which the needs of the individual patient should be considered. It therefore remains the responsibility of the individual clinician to interpret the application of these guidelines, taking into account local service constraints and the needs and wishes of the patient. It is not intended that these consensus documents are applied as rigid clinical protocols.

Principles:

  1. To provide national imaging guidelines for patients with gliomas. Given the differences in vendors, different sequences, their relative advantages and ongoing practices, some variations in sequences are likely.  
  2. To promote the use of volumetric imaging to assist with intraoperative navigation and follow-up comparisons. 
  3. If mobile MRI units are used, to recommend that these use the same protocols as the parent centre. 
  4. Same contrast media and dose should be used as much as possible across regional centres, otherwise equitable doses to be used. 
  5. To make use of imaging techniques such as MR spectroscopy, MR perfusion, functional MRI and tractography/DTI in addition to nuclear medicine imaging, at specialised centres, where necessary and possible.

Imaging requests

  1. These should include clinical history in detail, including the details of treatment provided including time and duration, also including steroid use and duration and pathology/molecular details. Any MDT discussion should be recorded briefly, including details of any special technique requested.
  2. Particularly, if the scan and report from a peripheral centre is being reviewed at regional centre, all details should be carefully recorded on the request.
  3. Post operative imaging in malignant glioma patients with an enhancing component to be done within 72 hours, as per the Brain and CNS cancer clinical QPIs 4.0.

Imaging protocol

  1. T1 volume or 2D T1 FSE/TSE axials. The volumetric sequence can be MPRAGE/FSPGR or SPACE/CUBE/VISTA type sequences with isotropic matrix if possible. These should be standardised across the regional centre, including slice thickness, orientation and matrix as closely as feasible.
  2. FLAIR volume. To use uniform standardised protocols across regional scanners. However, if the quality of 3D FLAIR sequence is thought to be suboptimal or if the scan is performed on mobile scanners, a 2D FLAIR axial can be added or substituted.
  3. DWI. Standard sequence in axial plane. This can also be performed after contrast injection (5) instead, before or after T2 axials but before post contrast T1 volume (7).
  4. Susceptibility weighted sequence (SWI, SWAN, VenoBOLD etc). Standard sequence in axial plane. This is ideally performed in the initial scan, although can be omitted in follow up scans and can be regionally agreed. If unavailable, a T2 GRE sequence can be obtained instead.
  5. Contrast injection
  6. T2 axials. Standard sequence in axial plane (to be done before 7).
  7. DWI (same as 3, if not done at 3, it can be done here as option).
  8. T1 volume. The volumetric sequence should be same as 1. Where MPRAGE type sequence is used, this can be supplemented by a 2D T1 FSE. 

Advanced techniques

These are sometimes used to detect early transformation of low grade to high grade glioma if not performing early debulking. These can include the following depending on the preference or expertise of the regional centre: 

  1. MR perfusion. The exact technique to be agreed with the regional centre, regarding use of DSC or DCE. If DSC is being used, whether to use preloading or not and amount of contrast and split if any to be used. 
  2. MR spectroscopy. Single voxel or multivoxel as determined by the local centre. MRS may be a result of MDT discussion.
  3. Nuclear medicine examinations, SPECT or PET, if local expertise.

Imaging time points

HGG: This is only a suggestive broad guideline, can be modified during MDT discussion as appropriate.

  1. Initial diagnosis
  2. Pre-operative, if original imaging more than 4 weeks old.
  3. Immediate post-operative (within 72 hours)
  4. Pre-chemotherapy/radiotherapy commencement (if immediate post-operative MRI unavailable or unsuitable).
  5. Monitoring during treatment.
  6. Post treatment.

LGG: This is only suggestive broad guideline, can be modified during MDT discussion as appropriate.

  1. Initial diagnosis
  2. Follow up at 3 months (sooner if there is a doubt about being LGG on initial imaging or clinical deterioration)
  3. Preoperative (if no recent imaging)
  4. First Postoperative scan (this can be variable, the timing of this should be agreed with the regional centre.
  5. Pre-chemotherapy/radiotherapy commencement (if immediate post-operative MRI was not performed).
  6. Monitoring during treatment.
  7. Post treatment.

References & contributors

Adapted with modifications from BSNR Standards Sub-Committee, Core Imaging protocol for brain tumours.

Agreed between Glasgow, Edinburgh, Aberdeen and Dundee Neuro-Oncology centres.

Contributors:

Dundee- Dr Avinash Kanodia (Lead),

Glasgow- Dr Natasha Fullerton,

Edinburgh- Dr David Summers,

Aberdeen- Dr Arnab Rana

Editorial Information

Last reviewed: 20/09/2023

Next review date: 20/09/2026

Author(s): Avinash Kanodia on behalf of the Neuro-Oncology Imaging Subgroup.

Version: 1

Reviewer name(s): Noelle O'Rourke.