Interstitial pituitary irradiation with 90Y for the treatment of acromegaly. A reappraisal.

The management of 54 acromegalics referred to us between 1974 and 1978 has been analysed. Twenty-two patients were treated with pituitary implants of yttrium-90 (90Y). Eleven are in complete remission (mean growth hormone (GH) less than 11 mIU/l), 8 had improved (mean GH 11-20 mIU/l or 50% less than preoperatively) and 3 were poor responders. Two patients had temporary 6th nerve paresis. Seven patients are on replacement therapy. Thirty-one patients were not implanted for the following reasons with a number of patients having more than one: extension of the tumour into the sphenoid sinus 10, or above the sella 3, partially empty sella 9, internal carotids too close to midline 2, invisible landmarks 1, mild acromegaly 6, poor general health 3, declined investigations or operation 6. It is concluded that pituitary implant of yttrium is an effective and safe form of treatment in carefully selected patients.