Clinical Outcomes in Patients With NFPAs Treated With Stereotactic Linear Accelerator Radiation Therapy

Background: Non-functioning pituitary adenoma (NFPAs) are benign tumors of the pituitary gland characterized by the absence of hormonal hypersecretion. Surgical treatment and fractionated stereotactic radiotherapy (FSRT) are necessary in majority of patients. NFPAs appear to cause higher mortality compared to the general population. Objective: To assess outcomes in patients with NFPAs treated with stereotactic linear accelerator radiation therapy. Material and Methods: Comparative, observational, longitudinal study, with prolective evaluation, from January 1987 to August 2019. Results: 264 patients (65.5% women and 34.5% men, mean age 43 ± 16 years) with a diagnosis of non-functional adenomas were evaluated. 30 patients received FSRT (14%), 93% were macroadenomas, and 80% of the cases were operated as a first line of treatment. The mean number of surgeries before radiotherapy was 1.2+-.847 (0-4). FSRT were used in 91.7% (n=21) because of post-surgical recurrence. Diabetes insipidus after surgery was transitory in 5.4%, and persistent in 4.0%. Hypopituitarism was identified in 59.4% before radiation (n=19), and in 13 patients (7.7%) after mean of 6.5+-5.5 years of FSRT. Dyslipidemia (62.0% vs. 45.9%), high blood pressure (16.5% vs. 23%), type 2 diabetes mellitus (10% vs. 77%) and heart failure (10% vs. 8.4%) were observed in the irradiated vs. non-irradiated groups, respectively (p<0.05). Conclusions: FSRT is a useful and safe strategy as an adjuvant treatment in patients with NFPA.