Impact of reduced preventive cranial radiotherapy (CRT) in medium-risk patients with a BFM-RF of 1.2 or higher and no central nervous system (CNS) involvement initially.

Shown is the cumulative incidence of relapse with CNS involvement compared with any other kind of relapse in trials ALL-BFM 86 (preventive CRT dose, 18 Gy) and ALL-BFM 90 (preventive CRT dose, 12 Gy).