Treatment of Acute Lymphoblastic Leukaemia: Effect of "Prophylactic" Radiotherapy against Central Nervous System Leukaemia: REPORT TO THE MEDICAL RESEARCH COUNCIL BY THE LEUKAEMIA COMMITTEE AND THE WORKING PARTY ON LEUKAEMIA IN CHILDHOOD

Abstract

A total of 177 patients with acute lymphoblastic leukaemia aged 1 to 13 years were entered in a trial in which one of the variables was “prophylactic” treatment against central nervous system (C.N.S.) relapse. Patients who achieved haematological remission on a standard chemotherapy regimen either received or did not receive craniospinal irradiation plus intrathecal methotrexate. Of the 80 patients who did not receive prophylactic C.N.S. treatment remission was terminated by meningeal leukaemia in 26. The corresponding figure for patients given prophylactic C.N.S. treatment was only 1 out of 75. The incidence of marrow relapse, however, is so far similar in the two groups. If the occurrence of either meningeal leukaemia or marrow relapse is taken to indicate recurrence of leukaemia then 32 out of 80 patients receiving no C.N.S. prophylaxis have so far relapsed compared with 14 out of 75 patients who received C.N.S. prophylaxis. This represents a halving of the recurrence rate in the prophylactic group: it is estimated that 75% of this group will remain free of either form of recurrence for 71 weeks after radiation treatment.