Background People living with primary malignant brain tumours (PMBT) face a complex and unpredictable illness. Throughout the disease course they undergo various treatments and follow-up with regular interval scanning. There are potential costs and benefits to interval scanning, however there is no high-quality evidence to suggest interval scanning is beneficial or whether scans alter outcomes of importance for people living with PMBTs. Yet, interval scanning may exacerbate issues such as uncertainty and anxiety - which impacts on patient quality of life. The aim of this study was to gain an in-depth understanding of how adults living with PMBTs experience and cope with interval scanning. Material and Methods Twelve patients with a diagnosis of PMBT (glioblastoma n=10; astrocytoma grade 3 n=1; solitary fibrous tumour of the dura grade 3 n=1) under the neuro-oncology teams at Leeds Teaching Hospital NHS Trust and King's College Hospital NHS Foundation Trust took part in the study. They were interviewed remotely about their experiences of interval scans, following a semi-structured interview guide. An abbreviated version of a constructionist grounded theory approach was used to analyse data. Results Five main themes were generated from the data: ‘Living with a PMBT’, ‘Interval scanning: the difficult times’, ‘MRI scan: accepting the discomfort’, ‘Waiting for results: coping with the uncertainty’ and ‘Results: providing some certainty in uncertainty’. Although most participants found interval scans uncomfortable, they accepted that they were something that they had to do and were using various coping methods to get through the MRI scan. All participants said that the wait between their scan and results was the most difficult part. Despite the difficulties they experienced, all participants said that they would prefer to have interval scans than wait for a change in their symptoms. Most of the time, scans provided relief, gave participants some certainty in an uncertain situation, and a short-term sense of control over their lives. Conclusion The present study shows that interval scanning is important and highly valued by patients living with PMBT. Although interval scans are anxiety provoking, they appear to help people living with PMBT cope with the uncertainty of their diagnosis.

Purpose People with primary malignant brain tumors (PMBT) undergo anti-tumor treatment and are followed up with MRI interval scans. There are potential burdens and benefits to interval scanning, yet high-quality evidence to suggest whether scans are beneficial or alter outcomes of importance for patients is lacking. We aimed to gain an in-depth understanding of how adults living with PMBTs experience and cope with interval scanning. Methods Twelve patients diagnosed with WHO grade III or IV PMBT from two sites in the UK took part. Using a semi-structured interview guide, they were asked about their experiences of interval scans. A constructivist grounded theory approach was used to analyze data. Results Although most participants found interval scans uncomfortable, they accepted that scans were something that they had to do and were using various coping methods to get through the MRI scan. All participants said that the wait between their scan and results was the most difficult part. Despite the difficulties they experienced, all participants said that they would rather have interval scans than wait for a change in their symptoms. Most of the time, scans provided relief, gave participants some certainty in an uncertain situation, and a short-term sense of control over their lives. Conclusion The present study shows that interval scanning is important and highly valued by patients living with PMBT. Although interval scans are anxiety provoking, they appear to help people living with PMBT cope with the uncertainty of their condition.