FIGURE S1 The hyper-FRT regimen reduces damage to normal skin. Mice bearing different orthotopic HGG (37.3, 37.5, 37.6, 37.7: pediatric 239/12; 37.10, 37.11, 37.15, 37.17, 37.18: adult DR177; 37.19: adult COMI) were irradiated to the whole head with total 13.0 Gy by a hypo-FRT (a, b; 2.5, 3.8 ,4.2 Gy fractions) or hyper-FRT (c, d; 0.25, 0.75 ,1.15, 1.45 Gy fractions) regimen as shown in the right hand panels (b, d). Hypo-FRT: four fractions of size ranging 2.5 – 4.2 Gy. Hyper-FRT: fourteen fractions of size ranging 0.25 – 1.45 Gy. Unlike the hyper-FRT, the hypo-FRT mice were visibly damaged to the head skin by RT

FIGURE S2 The hyper-FRT regimen reduces vascular damage to normal brain. (a) Sites of perivascular edema (indicated with arrows) in normal brain parenchyma from mice treated with 4 × 2.5 Gy fractions delivered at d37-d58 (hypo-FRT). (b) Similar sites of perivascular edema were less frequently observed in normal brain parenchyma from mice treated with 23 × 0.25 Gy fractions delivered at d37-d114 (hyper-FRT)