Endocrine Abstracts

Focussed radiotherapy or radiosurgery has been a disappointing alternativeto surgery as a primary treatment for pituitary adenomas. Our departmenthas delivered stereotactic multiple arc radiotherapy (SMART) through anadapted conventional linear accelerator (LINAC) for pituitary adenomas notcured by conventional therapy. We have treated 21 patients with biochemicaland/or radiological evidence of persisting disease despite maximalconventional therapy: all patients had undergone previous conventionalradiotherapy, 18 had also undergone prior surgery. This cohort comprised13 somatotroph adenomas, 4 corticotroph adenomas, 1 lactotroph adenoma and 3non-functioning pituitary adenomas (median follow-up: 33 months, range: 3-72months).

SMART has proven effective, safe and rapidly acting. We observed anaccelerated reduction in GH and IGF1 levels in patients with acromegaly,with GH and IGF1 levels rendered "safe" in 7 patients. Tumour growth wascontrolled in 2 out of 3 non-functioning pituitary adenomas, and 3 out of 4corticotroph adenomas.

There were no adverse effects from SMART. Notably there have been no visualsequelae, or further loss of anterior pituitary function in this heavilypre-treated group.

Our data indicate that SMART is an effective complementary therapy forpituitary adenomas which have displayed a sub-optimal response toconventional therapy including external irradiation.