**3.2 Hypopituitarism**

The pituitary gland is particularly sensitive to radiation, and hypopituitarism is the most common side effect after radiation therapy [65]. When high-dose radiation is applied directly to the pituitary gland for the treatment of pituitary adenomas, frequently it results in pituitary deficiency of one or more hormonal axes, and this correlates well with radiation dose to the pituitary gland [65, 66]. Furthermore, radiation damage of the hypothalamus can result in hypopituitarism [50]. Treatment requiring hypopituitarism of one or more hormonal axes has been reported in around 8% of these patients [7].
