- To estimate the progression free 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 the progression-free and overall survival distributions to molecularly and clinically matched historical controls from St. Jude SJMB03 study.