Treating childhood acute lymphoblastic leukemia without cranial irradiation.

TLDR: With effective risk-adjusted chemotherapy, prophylactic cranial irradiation can be safely omitted from the treatment of childhood ALL.

Abstract: Background Prophylactic cranial irradiation has been a standard treatment in children with acute lymphoblastic leukemia (ALL) who are at high risk for central nervous system (CNS) relapse. Methods We conducted a clinical trial to test whether prophylactic cranial irradiation could be omitted from treatment in all children with newly diagnosed ALL. A total of 498 patients who could be evaluated were enrolled. Treatment intensity was based on presenting features and the level of minimal residual disease after remission-induction treatment. The duration of continuous complete remission in the 71 patients who previously would have received prophylactic cranial irradiation was compared with that of 56 historical controls who received it. Results The 5-year event-free and overall survival probabilities for all 498 patients were 85.6% (95% confidence interval [CI], 79.9 to 91.3) and 93.5% (95% CI, 89.8 to 97.2), respectively. The 5-year cumulative risk of isolated CNS relapse was 2.7% (95% CI, 1.1 to 4.3), and t...