Neurotoxic Complications of CNS prophylaxis in Childhood Leukaemia

Abstract

There is general agreement that the biggest single advance in the treatment of childhood leukaemia in the last fifteen years has been the introduction of effective CNS prophylaxis against meningeal relapse, usually with a combination of cranial radiation and intrathecal methotrexate. With few exceptions this procedure has been adopted as standard in the last ten years and every Institution which sees a significant number of patients now has many long-term survivors who had cranial radiation and intrathecal prophylaxis as part of the treatment for their childhood acute lymphoblastic leukaemia (ALL). The long-term complications of the treatment process have become increasingly important as a consequence of the rising proportion of children with ALL who have been cured of their disease. Modifications of treatment regimens involve a delicate balance between seeking the maximum number of ‘cures’ while at the same time attempting to minimize the treatment sequelae which are the price that cured patients have to pay. The consequences of treatment are of particular importance when vital organs such as the brain are subjected to potentially harmful procedures as part of the treatment process. The observed long-term complications of irradiation for brain tumours include effects on intellectual performance and growth and development mediated by the hypothalamic-pituitary axis.