Pituitary fuction during X-ray treatment of the hypothalamic-pituitary region as evaluated by the TRH test response

The effect of conventional radiotherapy on the TRH response was studied in fourteen patients, all but one previously surgically treated for pituitary tumors. No change in the TSH response to TRH could be observed either during or after a four week treatment period, thus demonstrating relative resistance of the pituitary gland against irradiation in these patients. We also conclude that the diagnostic value of the TRH test remains unhampered during and in the immediate period after irradiation.