Gonadal function after cancer treatments in childhood

Treatments given for childhood malignancies can alter gonadal function by several mechanisms: (1) cranial irradiation may cause either gonadotrophin deficiency or premature puberty. (2) Irradiation of the testes can induce germinal epithelium dysfunction even if the dose delivered is very low; Leydig cell failure occurs beyond 5-6 Gy and ovarian insufficiency beyond 6-7 Gy. (3) Chemotherapy is considerably more toxic for the germinal epithelium of the testes than for the ovaries; alkylating agents are especially toxic. Analysis of the consequences of preparation for bone marrow transplantation by chemotherapy or total body irradiation will be required when longer follow-up are available.