Irradiation-induced growth failure.

GH deficiency, skeletal disproportion and early or precocious puberty may complicate irradiation to the head or axial skeleton in childhood. Certain cohorts of children are at particular risk, including those irradiated for brain tumours and various haematological malignancies. Both GH deficiency and impaired spinal growth may result in short stature, whereas the occurrence of early puberty in association with GH deficiency reduces the time available for GH therapy. The age of the child at irradiation is critical in that, in younger children, the central nervous system is more radiosensitive, the severity of the subsequent skeletal disproportion is greatest and the onset of puberty earliest. It is the very young craniospinally-irradiated child who is most at risk of extreme short stature.