engObrecht-Sturm, DeniseSchömig, LenaKortmann, Rolf-DieterGerber, Nicolas Uvon Bueren, André OFleischhack, GudrunSchüller, UlrichNussbaumer, GuntherBenesch, MartinRutkowski, StefanMynarek, MartinBison, BrigitteSchwarz, RudolfPietsch, TorstenPfister, Stefan MSill, MartinSturm, DominikSahm, FelixTreatment response as surrogate to predict risk for disease progression in pediatric medulloblastoma with persistent magnetic resonance imaging lesions after first-line treatment.info:eu-repo/classification/ddc/610HumansMedulloblastoma: diagnostic imagingMedulloblastoma: pathologyMaleChildFemaleMagnetic Resonance Imaging: methodsCerebellar Neoplasms: diagnostic imagingCerebellar Neoplasms: pathologyDisease ProgressionChild, PreschoolAdolescentFollow-Up StudiesPrognosisRetrospective StudiesSurvival RateInfantNeoplasm, Residual: diagnostic imagingNeoplasm, Residual: pathologyMRIchildrenmedulloblastomapersistent residual diseaseThis study aims at clarifying the impact of persistent residual lesions following first-line treatment for pediatric medulloblastoma.Data on 84 pediatric patients with medulloblastoma and persistent residual lesions on centrally reviewed magnetic resonance imaging (MRI) at the end of first-line therapy were analyzed.Twenty patients (23.8%) had residual lesions in the tumor bed (R+/M0), 51 (60.7%) had distant lesions (R0/M+) and 13 (15.5%) had both (R+/M+). Overall response to first-line therapy was minor or partial (≥ 25% reduction, minor response [MR]/PR) for 64 (76.2%) and stable disease (SD) for 20 patients (23.8%). Five-year post-primary-treatment progression-free (pptPFS) and overall survival (pptOS) were superior after MR/PR (pptPFS: 62.5 ± 7.0%[MR/PR] vs. 35.9 ± 12.8%[SD], P = .03; pptOS: 79.7 ± 5.9[MR/PR] vs. 55.5 ± 13.9[SD], P = .04). Furthermore, R+/M + was associated with a higher risk for progression (5-year pptPFS: 22.9 ± 17.9%[R+, M+] vs. 72.4 ± 12.0%[R+, M0]; P = .03). Watch-and-wait was pursued in 58 patients, while n = 26 received additional treatments (chemotherapy only, n = 19; surgery only, n = 2; combined, n = 3; valproic acid, n = 2), and their outcomes were not superior to watch-and-wait (5-year pptPFS: 58.5 ± 7.7% vs. 51.6 ± 10.7% P = .71; 5-year pptOS: 76.3 ± 6.9% vs. 69.8 ± 9.7%, P = .74). For the whole cohort, 5-year pptPFS by molecular subgroup (58 cases) were WNT: 100%, SHH: 50.0 ± 35.4%, group-4, 52.5 ± 10.5, group-3 54.2 ± 13.8%; (P = .08).Overall response and extent of lesions can function as surrogate parameters to predict outcomes in pediatric MB patients with persistent lesions after first-line therapy. Especially in the case of solitary persistent medulloblastoma MRI lesions, additional therapy was not beneficial. Therefore, treatment response, extent/kind of residual lesions and further diagnostic information need consideration for indication of additional treatments for persisting lesions.Neuro-Oncology 26(9), 1712 - 1722 (2024). doi:10.1093/neuonc/noae071info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionOxford Univ. Press2024info:eu-repo/semantics/closedAccessDEhttps://pub.dzne.de/record/271966https://pub.dzne.de/search?p=id:%22DZNE-2024-01108%22Researchersinfo:eu-repo/semantics/altIdentifier/pmid/pmid:38578306info:eu-repo/semantics/altIdentifier/issn/1522-8517info:eu-repo/semantics/altIdentifier/issn/1523-5866info:eu-repo/semantics/altIdentifier/doi/10.1093/neuonc/noae071