[Results of preventive management of the central nervous system in 275 children with acute lymphoblastic leukemia].
From 1970 to 1979, two subsequent BFM studies were performed with different modalities of systemic chemotherapy and preventive central nervous system (CNS) therapy. Eighteen out of 275 children experienced isolated CNS relapses within 2 years after diagnosis. The present analysis should clarify the following questions: 1. Could the risk for CNS relapse be assessed by initial diagnostic findings? 2. Is the CNS relapse rate influenced by more intensive systemic chemotherapy? 3. Is the CNS relapse rate altered by different doses of radiation therapy? The risk for relapse was assessed using a risk index (RI) based on findings at diagnosis. All patients were treated with an 8 weeks induction and consolidation chemotherapy protocol. In part, children with increased risk for relapse (RI greater than = 3) received an additional 6 weeks reinduction protocol within the first six months after diagnosis. Preventive treatment to the CNS consisted of radiotherapy at doses of less than = 18 Gy or 24 Gy and intrathecal methotrexate given during the consolidation phase. The results are as follows: 1. The RI proved to be predictive also for the risk of CNS relapse. However, CNS relapse rates were not substantially higher in children with RI greater than = 3 when they had been exposed to radiation doses of 24 Gy instead of less than = 18 Gy. 2. Intensive systemic reinduction therapy did not influence the CNS relapse rate in children with RI greater than = 3. 3. Three percent of children with RI less than = 2 experienced CNS relapses, irrespectively of lower or higher radiation doses. In patients with RI greater than = 3, however, irradiation at doses of less than = 18 Gy instead of 24 Gy led to a 3-4 fold higher incidence of CNS relapses, irrespectively of chemotherapy. We conclude that radiation doses of less than = 18 Gy are capable of preventing CNS relapses effectively in children with RI less than = 2. The exposure of patients with RI greater tha = 3 to doses of 24 Gy is justified.
D001932:Brain Neoplasms / Q000517:prevention & control*; D002648:Child; D003520:Cyclophosphamide / Q000627:therapeutic use; D006801:Humans; D007945:Leukemia, Lymphoid / Q000188:drug therapy* / Q000532:radiotherapy; D008577:Meningeal Neoplasms / Q000517:prevention & control*; D015122:Mercaptopurine / Q000627:therapeutic use; D008727:Methotrexate / Q000627:therapeutic use; D011241:Prednisone / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D012306:Risk; D014750:Vincristine / Q000627:therapeutic use
D014750:Vincristine; D003520:Cyclophosphamide; D015122:Mercaptopurine; D011241:Prednisone; D008727:Methotrexate
Ergebnisse der präventiven Behandlung des Zentralnervensystems bei 275 Kindern mit akuter lymphoblastischer Leukämie.