Moyamoya syndrome following childhood acute lymphoblastic leukemia

BACKGROUND: Long-term survivors of childhood acute lymphoblastic leukemia (ALL) sometimes suffer from adverse long-term sequelae. We analyzed the incidence, clinical course and prognosis of moyamoya syndrome (MoS) following childhood ALL. PROCEDURE: A total of 1,846 ALL patients were treated with four consecutive TCCSG ALL protocols (L84-11, L89-12, L92-13, and L95-14) between 1984 and 1999. We surveyed the MoS cases among these patients in the follow-up studies. RESULTS: Six patients with MoS were identified: four boys and two girls whose ages ranged from 2 years and 1 month (abbreviated as "2y1m") to 14y 1 m at diagnosis of ALL. None of the patients had central nervous system (CNS) leukemia. All six patients received prophylactic cranial irradiation with a dosage of 18 or 24 Gy. Although one patient died of brain infarction due to MoS, no leukemic relapse was observed in the group. The cumulative incidence of MoS in our series was 0.46 +/- 0.02% at 8 years. Among several clinical characteristics, use of cranial irradiation was the only factor that appeared to be significantly related to the development of MoS. CONCLUSIONS: MoS occurs with increased frequency in children treated for ALL, and might be associated with cranial irradiation. Prophylactic cranial irradiation should be used cautiously in ALL patients who can be cured by other CNS-directed therapies.