Abstract BACKGROUND Standard treatment for medulloblastoma in patients >3 years of age consists of tumor resection, radiation and chemotherapy using vincristine, cisplatin, cyclophosphamide +/- CCNU. Vincristine and Cisplatin are known to cause chemotherapy induced peripheral neuropathy (CIPN). The prevalence of CIPN in children with non-CNS cancers can be measured using the pediatric-modified Total Neuropathy Score (ped-mTNS). The purpose of this observational, retrospective pilot design is twofold: to investigate the prevalence of CIPN in children with medulloblastoma receiving neurotoxic chemotherapy, and to examine the feasibility of using the ped-mTNS as a measurement tool in this population. METHODS Data was manually extracted from medical records and entered into a REDCap database for analysis. The percent of patients successfully tested and clinical inferences made from ped-mTNS testing results were used to determine feasibility and barriers to use. A total of 33 medulloblastoma patients >3 years of age were treated from 6/2013 - 6/2021 at Children’s Minnesota. Of those, 18 received testing using the ped-mTNS during chemotherapy treatment. RESULTS During cancer treatment, 54.5% of the cohort of patients received ped-mTNS testing. The average age of children tested was 10.26 (4.39) years with a majority being male (79%), and non-Hispanic white race/ethnicity (89%). Of the tested participants, 61.1% had more than one measurement. For those patients tested at multiple timepoints, 72.7% demonstrated worsening ped-mTNS scores while on chemotherapy treatment. Therapists recorded inferences relating to neuropathy in 88.1% of testing occurrences with questions of accuracy recorded in 31.3% of testing occurrences. Barriers to use of results included confounding impairments that may occur as a result of the primary tumor, post-surgical changes, and radiation. CONCLUSIONS Using the ped-mTNS is feasible in children and adolescents with medulloblastoma. The ped-mTNS scores indicated that children with medulloblastoma, treated with Vincristine and Cisplatin, experience worsening neuropathy while undergoing chemotherapy treatment.