The medul-lo down.

Top Line: Time for a pediatric medulloblastoma update.

The Studies: A longitudinal study of intelligence testing among children treated with radiation for medulloblastoma compared outcomes for photon versus proton radiation. Children treated with photons had significant decline in multiple intelligence domains after radiation. In contrast, children treated with protons largely maintained intelligence scores with the exception of processing speed. In a second study, de-intensified chemo alone was tested in young children with nodular desmoplastic medulloblastoma, a subset thought to have a more favorable prognosis, while European data suggests intraventricular methotrexate alone may have favorable outcomes. ACNS1221 was designed to see a regimen using intravenous instead of intraventricular methotrexate could maintain these favorable outcomes with a goal of progression-free survival (PFS) of 90% or more at 2 years. Unfortunately, the trial closed early due more progressions than expected. To be precise, at 2 years, the hoped-for 90% PFS was actually 52%. Notably, all progression events happened in patients with nodular desmoplastic subtype.

TBL: Proton therapy appears to better preserve intelligence in children with medulloblastoma. However, trying to limit neurotoxicity by avoiding radiation and intraventricular chemo altogether results in unacceptably high rates of relapse. | Kahalley and Lafay-Cousin, J Clin Oncol 2019