Endocrine Abstracts

Introduction: Sterotactic radiosurgery (SR) has been used to treat recurrent adenomas and also as a primary treatment. The objective is to evaluate long-term tumor control, development of hypopituitarism and other side effects in the follow-up.

Patients and method: Retrospective analysis of 21 patients with non-functioning pituitary adenomas (NFA) treated with modified linear accelerator (LINAC) between 1998 and 2009 in three tertiary Spanish hospitals. Control of tumor size was defined as unchage or decrease of tumor size.

Results: The average follow-up period was 6.2 years. The cohort consisted of 61.9% of women and 30.1% of men with an average age of 45.3 years. LINAC was the primary treatment in 3 patients, while the remaining 18 patients had undergone one/two prior surgical resections. Inmunohistochemical data shows 9 silent pituitary tumors, 4 patients were catalogued as “null cell “ and the remaining 8 as NFA in the strict sense. The mean dose of treatment was 16.2 Gy (±2.01 SD). Prior to radiosurgery, pituitary hormone deficits were observed in 66.7% patients. New endocrine deficiencies were described in 11 patients during the follow-up. Tumor volume decreased in 52.3% patients, increased in 38.1% patients, and was unchanged in 9.5% patients. Tumor size decrease was statistically significant 12 months after radiosurgery (14.5 mm vs 12.3; P=0.03). Side effects presented in half of the patients were transitory. Seven patients presented cognitive problems 12–18 months after radiosurgery, one patient suffered a stroke in the fourth year after SR and other patients developed a second tumor nine years after SR.

Conclusions: LINAC resulted in a tumour size control of 61.8% in patients with NFA. Response to SR was statistically significant 1 year after treatment. Precocious side effects are usually transitory. The follow-up allows to detect new endocrine deficits and other side effects that may appear in the long term.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector