MDB-81. THE ROLE OF SURVEILLANCE IMAGING IN DETECTING RECURRENCE OF MEDULLOBLASTOMA

Abstract

Abstract BACKGROUND In patients with medulloblastoma, imaging with magnetic resonance imaging (MRI) of the brain and spine plays an integral role in surveillance following treatment completion. The primary objective of imaging surveillance is to detect early recurrences, possibly leading to better salvage treatment. However, there is a lack of data to demonstrate the utility of imaging with possible demerits associated with increased resource utilization, scan-related anxiety, and lead or length time bias. METHODS Patients with histopathological confirmation of medulloblastoma treated in our institute between 2005 and 2022 were screened to identify patients with image-detected recurrences and corresponding documentation of symptoms and imaging intent (surveillance or directed by symptoms). RESULTS From a cohort of 545 patients treated during the period, 212 had disease recurrence, of which 153 had known symptomatology during the first recurrence. A total of 114 patients (75%) were having recurrence detected prompted by symptoms. Group 4 medulloblastomas were commonly seen to have recurrence detected on surveillance imaging (35%) compared to the SHH subgroup (25%) and group 3 (12%). During the final analysis, 141 of 153 patients had died. The median survival of patients detected to have asymptomatic relapse was 14 months compared to 5 months for symptomatic recurrences (p=0.03). The overall survival (calculated from index diagnosis) was not statistically significant between the two groups, with a 3-year survival of 53% (asymptomatic) vs 46% (symptomatic) (p=0.51). CONCLUSION In most patients, recurrences were detected by unplanned imaging ahead of scheduled surveillance imaging prompted by symptoms. Although the survival after recurrence is better in patients diagnosed on surveillance imaging, the overall survival was not different between the two groups, suggesting the possibility of lead time bias. Prospective studies are warranted to determine the role and appropriate frequency of surveillance imaging in patients with medulloblastoma.