<prompt> Intracranial Irradiation most commonly leads to deficiency ofTSHACTHPROLACTINGROWTH HORMONE  <response>: Growth Hormone is most radiosensitive pituitary hormone and intracranial irradiation leads to hypopituitarism mainly due to hypothalamic damage rather than pituitary damage Least radiosensitive pituitary hormone is TSH 