PP74. SERIAL IMAGING OF INCIDENTAL MENINGIOMAS: ARE WE DOING TOO MANY SCANS?

Abstract

AbstractINTRODUCTION: We have observed a rise in referrals of patients with incidental meningiomas. It is widely accepted that the majority of these cases can be managed conservatively by monitoring with serial scans. However, there is no clear consensus or widely accepted guidance on the frequency of scanning or the duration of follow up. We reviewed the management of conservatively treated meningiomas in our unit. METHOD: Patients presenting to the unit between 06/01/2009 and 12/08/2015 with a radiological diagnosis of meningioma were identified from neuro-oncology MDT records. Incidental meningiomas were defined as either being asymptomatic (i.e. scan performed for other reason) or meningiomas in patients whose symptomatology was discrete from their radiological appearances. The baseline characteristics for each patient, dates of each scan and scan outcome were recorded. RESULTS: 131 incidental meningiomas managed under a conservative, ‘watch and wait’ strategy were identified and a total of 448 surveillance scans were performed. The mean duration of follow up was 28.5 months (range 3.0–71.9 months). 11 patients showed radiological progression during their follow up period and two underwent surgical excision. The median time to progression was 24.8 months (range 3.7–67.2 months). No patient was shown to have progression after their fourth consecutive scan. There was no clear factor (i.e. location or size of tumour) to indicate risk of progression. CONCLUSION: It is likely that the majority of patients with incidental meningiomas are being over imaged during extended surveillance periods, taking up valuable radiological resources and clinic time. Our preliminary data suggests that 5 serial scans over a 5 year period are likely to provide safe and sufficient follow up for small asymptomatic meningiomas. Expansion and follow up of this cohort continues with a view to identifying factors which may predict tumour growth.