Efficacy of intrathecal methotrexate with and without cranial radiotherapy in preventing central nervous system relapses in acute lymphocytic leukemia.

Introduction of CNS chemoprophylaxis was a major milestone in the development of current therapy for acute lymphocytic leukemia. However, controversies are still existing for ideal form of CNS chemoprophylaxis. The present study was conducted to determine the efficacy of intrathecal methotrexate (IT-MTX) with and without cranial radiotherapy in preventing CNS relapses in Indian children. CNS chemoprophylaxis comprising of six injections of intrathecal methotrexate (12 mg/M2) was administered alone or along with cranial radiotherapy (2000 GY) in 76 children each after successful induction remission. Cranial radiotherapy (RT) with intrathecal methotrexate (IT-MTX) was observed to be more effective as CNS relapses were seen in 11.8% of children as compared to 16.8% of children receiving IT-MTX alone. IT-MTX along with cranial RT delayed the occurrence of CNS relapses and prolonged the event free survival periods.