Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2018 Jul 1;101(3):618-623.
doi: 10.1016/j.ijrobp.2018.02.169. Epub 2018 Mar 8.

Hypopituitarism After Single-Fraction Pituitary Adenoma Radiosurgery: Dosimetric Analysis Based on Patients Treated Using Contemporary Techniques

Christopher S Graffeo  1 , Michael J Link  2 , Paul D Brown  3 , William F Young Jr  4 , Bruce E Pollock  5
Affiliations

Hypopituitarism After Single-Fraction Pituitary Adenoma Radiosurgery: Dosimetric Analysis Based on Patients Treated Using Contemporary Techniques

Christopher S Graffeo et al. Int J Radiat Oncol Biol Phys. .

Abstract

Purpose: To analyze factors associated with post-stereotactic radiosurgery (SRS) hypopituitarism among radiation-naïve patients with pituitary adenomas who underwent single-fraction SRS between 2007 and 2014.

Methods and materials: This was a retrospective review of 97 patients having single-fraction SRS from 2007 until 2014. Eligible patients had no history of prior radiation, normal age- and sex-specific pituitary function before SRS, and at least 24 months of endocrine follow-up. Forty patients (41%) had hormone-secreting tumors; 57 patients had nonsecreting tumors (59%). The median prescription isodose volume was 2.8 cm3 (interquartile range [IQR], 1.3-4.7); the median tumor margin dose was 20 Gy (IQR, 15-25 Gy).

Results: The median follow-up after SRS was 48 months (IQR, 34-68 months). Twenty-seven patients (28%) developed pituitary insufficiency at a median of 22 months (IQR, 12-36 months) after SRS. The rate of new endocrine deficits was 17% at 2 years (95% confidence interval [CI] 10%-25%) and 31% at 5 years (95% CI 20%-42%). Male sex (hazard ratio [HR] 2.38, 95% CI 1.05-5.26, P = .04), smaller pituitary gland volume (HR 0.99, 95% CI 0.99-0.99, P = .01), and higher mean pituitary gland dose (HR 1.31, 95% CI 1.16-1.47, P < .001) were associated with post-SRS hypopituitarism in multivariable analysis. The rate of hypopituitarism for patients with a mean gland dose of <11.0 Gy at 2 years was 2% (95% CI 0%-4%) and at 5 years was 5% (95% CI 0%-11%), whereas rate of hypopituitarism for patients with a mean gland dose of ≥11.0 Gy at 2 years was 31% (95% CI 17%-43%) and at 5 years was 51% (95% CI 34%-65%).

Conclusions: Hypopituitarism after pituitary adenoma SRS increases in a time- and dose-dependent manner. Reducing the radiation exposure to the identifiable gland to a mean dose < 11.0 Gy whenever feasible may lower the incidence of new hormonal deficits after pituitary adenoma SRS.

PubMed Disclaimer

LinkOut - more resources