Effects of radiotherapy on the growth of children with leukemia

The five-year overall survival rates of childhood lymphoblastic leukemia (ALL) have recently increased to more than 80%. During recent years, CNS radiation doses delivered to all children with ALL according to international guideline protocols have decreased. In the 1980s, the prophylactic radiation dose to the CNS decreased from 2400 cGy to 1800 cGy; in the 1990s chemotherapy alone with intrathecal chemotherapy demonstrated that there was no need for prophylactic CNS radiation in standard risk ALL, except in CNS relapse and high risk patients. Late effects on pituitary function and growth were reported by most endocrinologists involved in the follow-up of the cancer survivors. The long-term effects of cranial irradiation on growth in children treated for ALL are reviewed, specifically addressing the deficit in final height, contributing factors for height deficits, growth catch-up after stopping therapy, and growth hormone replacement therapy.