With lower dose external beam radiotherapy (<30 Gy) isolated growth hormone (GH) deficiency may be seen (the GH axis seeming to be the most radiosensitive), whereas high doses (>60 Gy) may result in a 30%–60% rate of gonadotropin, adrenocorticotropic hormone (ACTH) and thyroid‐stimulating hormone (TSH) deficiency after 10 years.8 This evidence concerns the gene POMC and central congenital hypothyroidism.