A 21 year old male presented with sho stature & lack of secondary sexual characteristics. He has been operated for brain tumor 12 years ago & underwent cranial radiation. Which of the following is true regarding acquired hypopituitarism due to radiation?

Cranial irradiation may result in long-term hypothalamic and pituitary dysfunction. At a dose of 50 Gy of radiation, up to two-thirds of patients develop hormone insufficiency The development of hypopituitarism occurs over 5-15 years after cranial radiation Growth hormone deficiency is most common, followed by gonadotropin and ACTH deficiency Children and adolescents are at highest risk from radiation-induced hypopituitarism