Posterior reversible encephalopathy syndrome (PRES) in children with acute lymphoblastic leukemia has been increasingly recognized as a clinicoradiological entity. Our aim was to describe the incidence of PRES in pediatric patients with ALL, identify its risk factors, and examine its prognostic importance. For this
research, we conducted a systematic, retrospective review of the patient records in a population-based series of children with acute lymphoblastic leukemia (n=643) treated in Finland from 1992 to 2008. Of the patients with ALL, 4.5% (n= 29) developed radiologically confirmed PRES, of which 28 cases occurred during induction. Hypertension (P=0.006; odds ratio [OR], 4.10, confidence interval [CI], 1.50-11.25), constipation (P=0.001; OR, 5.60; CI, 2.02-15.52), and >14 days of alkalinization (P=0.017; OR, 3.27; CI, 1.23-8.68) were significant independent risk factors for PRES. One-third of the patients developed epilepsy. Relapses occurred significantly more often in those patients with PRES (P= 0.001), which was associated with worse overall survival (P= 0.040; 5-year survival=75.9% [60.3%-91.4%] vs. 88.4% [85.8%- 90.9%]). Using NOPHO-ALL 92/2000 protocols, PRES is a significant early complication of therapy in ALL, and was associated with a poorer prognosis and significant neurological morbidity.