MB-95: RESIDUAL LESIONS AFTER COMPLETION TREATMENT FOR CHILDHOOD MEDULLOBLASTOMA

PURPOSE: To investigate the outcome of patients with residual abnormalities on MRI imaging after completion treatment for medulloblastoma (MB). METHODS: We retrospectively reviewed 212 children with newly diagnosed MB treated at Gustave Roussy between January 2000 and December 2013. We assessed residual radiological abnormalities at the end of first-line treatment. RESULTS: Out of 212 patients, 32 children had residual lesions on MRI imaging after completion treatment. The median age was 4.1 years [0.1 to 14.7]. Eleven patients had classic MB, 2 had large cell/anaplastic MB, one had desmoplastic MB and 18 had not otherwise specified MB. 26 children had metastatic disease at diagnosis. A the end of first-line treatment, 9 patients had residual lesion at primary site, 14 had residual abnormalities at metastatic site and 9 had residual lesion at both. A relapse occurred in 20 children (63%) with a median time to relapse of 8.5 months [1 to 53]. Despite persistent MRI findings, 12 patients are alive and well at last follow-up CONCLUSION: The possibility of having residual findings on imaging with no clinical implication should be taken under consideration. The nature of these residual abnormalities is discussed.