The SCAN-ME Study Protocol: The Value of Surveillance Imaging for Children and Young People with Medulloblastoma and Ependymoma

Abstract Background After treatment ends, children, and young people (CYP) with medulloblastoma and ependymoma undergo surveillance imaging to check for cancer recurrence. Surveillance imaging aims to detect tumour relapse before symptoms develop, but the evidence to suggest that they improve outcomes is uncertain. Notwithstanding, scans are costly, and are an emotional burden for families. Aims and Objectives This mixed methods project will explore the value of surveillance imaging for children with medulloblastoma and ependymoma in three workstreams. 1) Workstream 1: Explore CYP and their parent’s experiences and expectations of surveillance imaging for detecting recurrent medulloblastoma and ependymoma. 2) Workstream 2: Using individual participant data (IPD), determine whether detecting a relapse surveillance imaging in CYP with medulloblastoma or ependymoma improves survival outcomes and treatment options. 3) Workstream 3: Determine whether surveillance imaging for CYP with medulloblastoma or ependymoma is cost-effective. Methods 1) CYP with medulloblastoma and ependymoma who are undergoing surveillance imaging and their parents will be recruited to a qualitative study. Creative methods and semi-structured interviews will be used to understand CYP and parent’s experiences of surveillance imaging. Transcripts will be analysed using the ‘following the thread' method. 2) IPD from two UK-wide cohorts with data on CYP with relapsed ependymoma and medulloblastoma will be used to determine whether survival outcomes differ when relapse was detected symptomatically compared to asymptomatically. Multivariable survival analyses will assess the association between survival and method of relapse detection after controlling for prognostic variables (e.g., subtype, extent of surgical resection, subsequent therapies). 3) An economic model will be developed to evaluate whether surveillance imaging is value for money compared to no surveillance imaging. IPD from Workstream 2 will inform transition probabilities between health states. Costs, resource use and quality of life estimates will be obtained from systematic literature searches. Data from each workstream will be synthesised using a convergent parallel approach following data analysis. Discussion This study aims to explore surveillance imaging for CYP with medulloblastoma and ependymoma in a holistic way, making it easier for decision makers to weigh up the benefits and drawbacks value of providing routine scans for this population.