Stereotactic Radiosurgery XVI: A Treatment for Previously Irradiated Pituitary Adenomas

• Published in: The journal of clinical endocrinology and metabolism Vol. 88; no. 11; pp. 5334 - 5340
• Main Authors: Swords, F. M., Allan, C. A., Plowman, P. N., Sibtain, A., Evanson, J., Chew, S. L., Grossman, A. B., Besser, G. M., Monson, J. P.
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Endocrine Society 01.11.2003; Copyright by The Endocrine Society
• Subjects: Acromegaly - radiotherapy; Acromegaly - surgery; Adenoma - radiotherapy; Adenoma - surgery; Adolescent; Adult; Aged; Biological and medical sciences; Diseases of the nervous system; Endocrinopathies; Female; Follow-Up Studies; Human Growth Hormone - blood; Humans; Hypothalamus. Hypophysis. Epiphysis (diseases); Insulin-Like Growth Factor I - metabolism; Male; Medical sciences; Middle Aged; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Pituitary Neoplasms - radiotherapy; Pituitary Neoplasms - surgery; Radiosurgery - adverse effects; Radiosurgery - methods; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Treatment Outcome; Endocrinopathy; Human; Treatment efficiency; Radiosurgery; Somatotropin hormone; Stereotaxia; Adenoma; Insulin like growth factor 1; Radiotherapy; Protein hormone; Treatment; Adenohypophyseal hormone; Pituitary diseases; Secondary effect
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jc.2002-020356

We report the use of stereotactic radiosurgery delivered through an adapted linear accelerator [stereotactic multiple arc radiation therapy (SMART)] for pituitary adenomas not cured by conventional therapy. All 21 patients had undergone conventional radiotherapy (45–50 Gy); 18 had also undergone prior surgery. This cohort comprised 13 patients with somatotrope adenomas, four with corticotrope adenomas, one with a lactotrope adenoma, and three with nonfunctioning pituitary adenomas (median follow-up: 33 months, range: 3–72 months). SMART has proven effective, safe, and rapidly acting. We observed an accelerated reduction in GH and IGF-I levels in acromegaly, with normalization of GH and IGF-I levels in 58%. Mean GH fell from 21.1 mU/liter to 7.9 mU/liter (7 ng/ml to 2.6 ng/ml, P < 0.01, median 25 months) faster than our predicted fall to 50% at 2 yr with conventional radiotherapy. Mean IGF-I fell from 624 ng/ml to 384 ng/ml (P < 0.001). Tumor growth was controlled in two of three nonfunctioning pituitary adenomas, and three of four corticotrope adenomas. There were no adverse effects from SMART. Notably there have been no visual sequelae or further loss of anterior pituitary function in this heavily pretreated group. Our data indicate that SMART is an effective complementary therapy for pituitary adenomas that have displayed a suboptimal response to conventional therapy including external irradiation.