Glioblastoma post-operative imaging in neuro-oncology: current UK practice (GIN CUP study)

Abstract

Objectives MRI remains the preferred imaging investigation for glioblastoma. Appropriate and timely neuroimaging in the follow-up period is considered to be important in making management decisions. There is a paucity of evidence-based information in current UK, European and international guidelines regarding the optimal timing and type of neuroimaging following initial neurosurgical treatment. This study assessed the current imaging practices amongst UK neuro-oncology centres, thus providing baseline data and informing future practice. Methods The lead neuro-oncologist, neuroradiologist and neurosurgeon from every UK neuro-oncology centre were invited to complete an online survey. Participants were asked about current and ideal imaging practices following initial treatment. Results Ninety-two participants from all 31 neuro-oncology centres completed the survey (100% response rate). Most centres routinely performed an early post-operative MRI (87%, 27/31), whereas only a third performed a pre-radiotherapy MRI (32%, 10/31). The number and timing of scans routinely performed during adjuvant TMZ treatment varied widely between centres. At the end of the adjuvant period, most centres performed an MRI (71%, 22/31), followed by monitoring scans at 3 monthly intervals (81%, 25/31). Additional short-interval imaging was carried out in cases of possible pseudoprogression in most centres (71%, 22/31). Routine use of advanced imaging was infrequent; however, the addition of advanced sequences was the most popular suggestion for ideal imaging practice, followed by changes in the timing of EPMRI. Conclusion Variations in neuroimaging practices exist after initial glioblastoma treatment within the UK. Multicentre, longitudinal, prospective trials are needed to define the optimal imaging schedule for assessment. Key Points • Variations in imaging practices exist in the frequency, timing and type of interval neuroimaging after initial treatment of glioblastoma within the UK. • Large, multicentre, longitudinal, prospective trials are needed to define the optimal imaging schedule for assessment.

A Position Statement on the Utility of Interval Imaging in Standard of Care Brain Tumour Management: Defining the Evidence Gap and Opportunities for Future Research

“…In some centres, “advanced” MRI techniques (e.g. dynamic-susceptibility contrast enhanced, DSC, imaging or 1H-magnetic resonance spectroscopy MRS) or PET (targeting glucose or amino acid uptake) helps problem solving in instances when structural imaging is indeterminate ( 16 , 17 ). As an alternative to a planned imaging schedule, imaging can also be triggered by a change in symptomatology or clinician concern, regardless of any scheduled follow-up interval.…”

“…While triggered imaging is more difficult to organise at short notice, the strategy benefits from addressing patient concerns regarding the cause of new symptoms and providing the radiologist with contemporaneous clinical information at the time of imaging. In most centres the strategy for interval imaging is a combination of both a planned schedule and triggered imaging ( 16 ). Clinical and other non-imaging biomarkers of disease progression, whether as triggers for imaging or additional treatment response biomarkers, have the potential to be incorporated into the patient pathway and would benefit from further research ( Supplementary Information 1 ).…”

“…Clinicians, scientists, and patient advocates and representatives with expertise in interval imaging, data science, health economics or trial management of adult brain tumours, convened in London, UK, in April 2019 in conjunction with a National Cancer Research Institute (NCRI) Brain Tumour group workshop. Available evidence for interval imaging pathways for different tumour types was discussed in the context of research recommendations of previous publications, including the UK’s National Institute for Health and Care Excellence (NICE) brain tumour guidelines NG99 ( Supplementary Table 1 ) and a systematic review of glioma imaging ( 4 , 5 , 16 ). Specifically, we sought to assess value in the context of morbidity, mortality, quality of life and resource use (together these outcomes give the additional outcome measure of cost effectiveness).…”

“…There is a lack of biological specificity for contrast enhancement, particularly in the context of treatment effects and pseudophenomena, which can confound imaging assessment. There is also variability in clinical adoption of interval imaging practice across UK and European neuro-oncology centres which is unlikely to be in the best interests of patients or healthcare systems ( 16 , 17 ). It is also noteworthy that the widely reported observation that increasing enhancement tracks growth of most brain tumour types, has extended the use of contrast-enhancing tumour size as a biomarker beyond high-grade glioma.…”

“…It is also noteworthy that the widely reported observation that increasing enhancement tracks growth of most brain tumour types, has extended the use of contrast-enhancing tumour size as a biomarker beyond high-grade glioma. The impetus to derive an evidence-base is driven by researchers ( 4 , 5 , 16 ), but more importantly patients and carers ( Box 1 ) ( 18 ). This in part relates to factors such as understanding the anxiety surrounding the imaging event and awaiting the results – so-called “scanxiety” ( 19 ).…”