{"entity":{"id":"paper-acns0331-michalski-jco-2021","kind":"paper","name":"ACNS0331: reduced-dose and reduced-volume radiotherapy with chemotherapy for average-risk medulloblastoma","aka":[],"tldr":"Reducing the radiotherapy boost to the tumour bed instead of the whole posterior fossa was safe in average-risk medulloblastoma, but lowering the craniospinal dose from 23.4 to 18 Gy in young children led to more relapses, so the standard dose was kept.","summary":"Children's Oncology Group phase 3 trial of 464 children with average-risk medulloblastoma randomised to involved-field (tumour bed) versus whole posterior fossa boost, and, for children aged 3 to 7, to low-dose (18 Gy) versus standard-dose (23.4 Gy) craniospinal irradiation.\n\nFive-year event-free survival was 82.5 percent with involved-field boost versus 80.5 percent with posterior fossa boost (non-inferior), but 71.4 percent with 18 Gy against 82.9 percent with 23.4 Gy craniospinal irradiation (inferior); WNT tumours did well regardless.","asOf":"2026-09-17","links":[{"label":"J Clin Oncol 2021","url":"https://doi.org/10.1200/JCO.20.02730"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/34110925/"}],"tags":[],"related":[],"cancers":["medulloblastoma-group-3-4","medulloblastoma-wnt"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["acns0331"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":["jco"],"dependsOn":[],"notes":[],"journal":"Journal of Clinical Oncology","year":2021,"doi":"10.1200/JCO.20.02730","pmid":"34110925","authors":"Michalski JM, Janss AJ, Vezina LG, et al.","paperType":"rct","findings":["Involved-field boost non-inferior: five-year event-free survival 82.5 percent vs 80.5 percent.","18 Gy craniospinal irradiation inferior: 71.4 percent vs 82.9 percent."],"whatItMeans":"Tumour-bed boost is standard in average-risk medulloblastoma, while craniospinal dose reduction is reserved for the WNT-activated subgroup in trials.","caveats":["Molecular subgroup was determined retrospectively.","Neurocognitive outcomes were somewhat better with lower dose, highlighting the trade-off."],"changedPractice":true,"participants":464},"route":"/key-papers/paper-acns0331-michalski-jco-2021/","neighbours":{"cancer":[{"id":"medulloblastoma-group-3-4","kind":"cancer","name":"Group 3 and group 4 medulloblastoma (non-WNT/non-SHH)","route":"/cancers/medulloblastoma-group-3-4/"},{"id":"medulloblastoma-wnt","kind":"cancer","name":"WNT-activated medulloblastoma","route":"/cancers/medulloblastoma-wnt/"}],"trial":[{"id":"acns0331","kind":"trial","name":"COG ACNS0331","route":"/trials/acns0331/"}],"journal":[{"id":"jco","kind":"journal","name":"Journal of Clinical Oncology","route":"/journals/jco/"}]}}