Interval Scanning

The JLA Neuro-Oncology Priority Setting Partnership (link) identified the question of “What is the effect on prognosis of interval imaging to detect tumour recurrence, compared with scanning on symptomatic recurrence, in people with brain tumour.”

This area is therefore now a priority area for clinical research.

An estimated 5000 patients each year will be diagnosed with a primary brain tumour (glioma) in the UK. 85% will have high grade glioma and patients undergoing treatment are generally scanned frequently to assess response to treatment. Once treatment is over “surveillance imaging” is done but the appropriate frequency of imaging has not been well studied. The problem is even less certain in the 15% who have a low grade glioma (LGG) or meningiomas (generally benign tumours of the coverings of the brain), With low grade tumours the expected growth is very slow and the appropriate frequency of scanning is even less certain. Low grade gliomas, unlike other cancers, can change, or “transform”, to high grade gliomas, in more than 50% of cases. Malignant transformation to a high grade glioma would mandates treatment (radiotherapy or chemotherapy).

Identifying early tumour recurrence is an important focus of research1. Guidelines recognise that “no adequate data exist on the timing and role of imaging in the monitoring of response to therapy of glioma, however after the first year of imaging, a policy of scanning is usually followed unless new symptoms develop”.

More frequent, or more specialized, MRI sequences, may identify possible tumour progression earlier leading to earlier intervention with radiotherapy +/- chemotherapy, but whether this leads to better survival is unproven as it may simply seem to improve survival because of “lead time bias”.

Frequent MRI scanning will be more costly and minor changes on the MRI scan may simply alarm the patient, especially if there is not going to be any therapeutic intervention. Frequent interval scanning may result in patients being anxious and affect quality of life and patient satisfaction. (Scanxiety”)

Evidence based guidelines around intervals of scanning perhaps based on factors such as clinical and molecular biomarkers may be helpful. Health Economic Analysis would form part of the study.

The NCRI will hold an “Incubator Day” in 2016, to examine the current stage of research and advise on best design of any future study in the area.

If interested in supporting this research area, or learning more, please contact the NCRI Brain Supportive & Palliative Care Group and leave details of your interest. (email: S&