A Clinical and Molecular Risk-Directed Therapy for Newly Diagnosed Medulloblastoma

Primary Objectives: * To estimate the progression free survival distribution of WNT-medulloblastoma patients treated on Stratum W1 with reduced-dose craniospinal irradiation and reduced-dose cyclophosphamide. * To estimate progression-free survival distribution of Non-WNT Non-SHH medulloblastoma patients treated on Stratum N1 with reduced dose cyclophosphamide. * To estimate the progression free survival distribution of skeletally mature SHH medulloblastoma patients assigned to Stratum S1 and treated with oral maintenance therapy using a targeted SHH pathway inhibitor (vismodegib) after the adjuvant chemotherapy regimen is complete and to compare the outcome to molecularly and clinically matched historical controls from SJMB03 as well as outcome from other published cohorts. * To evaluate the effect of an aerobic training intervention, delivered during the radiation therapy period and at home, prior to the start of chemotherapy, on cardiopulmonary fitness. * To assess the impact of a computer-based working memory intervention (administered prophylactically at the end of chemotherapy), relative to standard of care, on a performance-based measure of working memory. Secondary Objectives: * To estimate overall survival distribution of WNT-medulloblastoma patients treated on Stratum W1 with reduced-dose craniospinal irradiation and reduced-dose cyclophosphamide and compare progression free and overall survival distributions to molecularly and clinically matched historical controls from St. Jude SJMB03 study. * To estimate the progression free (in S1 skeletally immature and S2 both sub-strata) and overall survival distributions of SHH medulloblastoma patients enrolled on Strata S1 and S2 some of whom will be treated with oral maintenance therapy using a targeted SHH pathway inhibitor (vismodegib) after adjuvant chemotherapy regimen is complete and compare these outcomes to molecularly and clinically matched historical controls from SJMB03 as well as outcome from other published cohorts. * To estimate the progression free and overall survival distributions of Non-WNT Non-SHH medulloblastoma patients treated on Strata N2 and N3 with 3 cycles of pemetrexed and gemcitabine in addition to 4 cycles of conventional adjuvant chemotherapy and compare the progression-free and overall survival distributions to molecularly and clinically matched historical controls from St. Jude SJMB03 study separately for each stratum. * To estimate the overall survival distribution of Non-WNT Non-SHH medulloblastoma patients treated on Stratum N1 with reduced dose cyclophosphamide and compare progression free and overall survival distributions to molecularly and clinically matched historical controls from St. Jude SJMB03 study. * To evaluate the feasibility and toxicity of adding pemetrexed and gemcitabine to adjuvant chemotherapy regimen of intermediate and high risk Non-WNT Non-SHH medulloblastoma patients (Strata N2 and N3). * To evaluate the feasibility and toxicity of oral maintenance therapy with the targeted SHH inhibitor (vismodegib) after conventional adjuvant chemotherapy regimen is complete. * To estimate the cumulative incidence of local disease failure at 2 and 5 years based on treatment regimen, strata, and clinical and treatment factors. * To evaluate the effects of an aerobic training intervention, delivered during the radiation therapy period and at home, prior to the start of chemotherapy, on physical performance, fatigue, health related quality of life, memory, attention and executive function at the end of the intervention, at the end of adjuvant chemotherapy, and one, two and five years off adjuvant chemotherapy, among children treated for medulloblastoma. * To evaluate the impact of an aerobic training intervention on sleep quality and quantity in children with medulloblastoma. * To evaluate the relation between baseline cognitive performance and the variables of sleep quality and quantity, and fatigue in children with medulloblastoma. * To estimate change in neurocognitive performance using a comprehensive assessment battery (e.g., measures of intellectual function, academic abilities, attention, memory, processing speed and executive functions) and investigate the relationship of change to relevant demographic factors (e.g., gender, age at treatment, time since treatment and socioeconomic status) and clinical factors (e.g., treatment intensity/risk group, posterior fossa syndrome). * To assess the impact of a computer-based working memory intervention, relative to standard of care, on additional performance- and rater-based measures of attention, processing speed and executive functions. * To compare the impact of a computer-based working memory intervention in conjunction with an aerobic training intervention, relative to either intervention in isolation, on measures of attention, processing speed and executive functions. * To evaluate the maintenance of improvements on measures of attention, working memory, processing speed and executive functions six months following participation in the computer-based working memory intervention program. Outline: This is a multicenter study. Patients are stratified according to molecular subgroup assignment (WNT, SHH, or Non-WNT Non- SHH) and then by clinical risk stratification (extent of resection, M stage, histologic subtype, and cytogenetic features). All patients will be treated with risk-adapted radiation therapy and adjuvant chemotherapy. Patients assigned to Stratum W1 will receive reduced dose radiation therapy. Patients assigned to Stratum W2, S1, N1, or N2 will receive standard dose radiation therapy. Patients assigned to Stratum W3, S2, or N3 will receive high dose radiation therapy. Radiation therapy will be followed by 4 cycles of adjuvant conventional chemotherapy with cyclophosphamide, cisplatin and vincristine for all patients. Patients assigned to Stratum N2 or N3 (Non-WNT Non-SHH with high risk factors) will receive 3 additional cycles of pemetrexed and gemcitabine chemotherapy intermixed into the conventional adjuvant chemotherapy cycles. Patients with SHH subtype (Stratum S1 or S2) who are skeletally mature will receive 12 months additional maintenance therapy with vismodegib. Patients may consent to provide tumor tissue, blood, and CSF samples for biological studies. Tumor tissues are analyzed for the activation of the WNT signaling pathway, activation of the SHH signaling pathway, validation of novel patterns of gene expression via immunohistochemical (IHC) analysis; validation of genetic abnormalities via interphase fluorescence in situ hybridization (iFISH); construction of gene expression profiles via microarray analysis; construction of DNA methylation profiling via microarrays; single nucleotide polymorphism (SNP) analysis for DNA copy number aberrations; potential oncogenes and tumor suppressor genes via DNA sequence analysis; expression of a number of cell signal proteins implicated in the biology of medulloblastoma via western blot; expression of additional proteins encoded by genes associated through SNP and gene expression array analysis with clinical disease behavior. Blood samples are analyzed from patients whose tumors contain gene mutations via sequence analysis of constitutional DNA. CSF and blood samples are analyzed for identification of potential tumor markers. Parents may consent to have blood samples analyzed for inheritable gene mutations associated with medulloblastoma. Patients may also consent to exploratory research that include additional functional MRI imaging to investigate damage to neural connections from therapy; additional psychological testing to identify neurocognitive effects of therapy; additional heart and lung testing to identify treatment effects; additional endocrine studies to identify treatment effect on growth and development. After completion of study treatment, patients are followed every 6 months for 5 years.