RESUMO
BACKGROUND: Higher risk of secondary brain tumor, carotid stenosis and stroke has been reported after conventional sella irradiation for pituitary neuroendocrine tumors (PitNET). Stereotactic radiosurgery (SRS), which is a more focused approach, is now increasingly used instead. The aim was to assess the risk of secondary brain tumor, carotid stenosis/occlusion and stroke after SRS. METHODS: In this multicentric retrospective study, 2,254 patients with PitNET were studied, 1,377 in the exposed group and 877 in the control group. RESULTS: There were 9,840.1 patient-years at risk for the SRS and 5,266.5 for the control group. The 15-year cumulative probability of secondary intracranial tumor was 2.3% (95%CI:0.5%, 4.1%) for SRS and 3.7% (95%CI:0%, 8.7%) for the control group (p=0.6), with an incidence rate of 1.32 per 1,000 and 0.95 per 1,000, respectively. SRS was not associated with increased risk of tumorigenesis when stratified by age (HR: 1.59 [95%CI: 0.57, 4.47], p=0.38). The 15-year probability of new carotid stenosis/occlusion was 0.9% (95%CI: 0.2, 1.6) in the SRS and 2% (95%CI: 0, 4.4) in the control group (p=0.8). The 15-year probability of stroke was 2.6% (95%CI: 0.6%, 4.6%) in the SRS and 11.1% (95%CI: 6%, 15.9%) in the control group (p<0.001). In cox multivariate analysis stratified by age, SRS (HR 1.85[95%CI:0.64, 5.35], p=0.26) was not associated with risk of new stroke. CONCLUSION: No increased risk of long-term secondary brain tumor, new stenosis or occlusion and stroke was demonstrated in SRS group compared to control in this study with imaging surveillance.
RESUMO
BACKGROUND: Delayed hypopituitarism is the most common complication after stereotactic radiosurgery (SRS) for pituitary adenomas. OBJECTIVE: To investigate the relationship between neuroanatomic structure distances from the radiation target and anterior pituitary function preservation after SRS through multicenter study. METHODS: We retrospectively reviewed the International Radiosurgery Research Foundation database from January 2002 to December 2021 for adult patients undergoing SRS for pituitary adenomas with >6 months of follow-up. Distances between centers or edges of hypothalamic-pituitary axis structures and SRS target volumes were measured using MRI. The primary outcome was anterior pituitary function preservation. Predictors were analyzed using multivariable logistic regression and area under the receiver operating curve (AUROC) curve analyses. RESULTS: Four hundred eighty-seven patients were categorized by preservation (n = 384) and no preservation (n = 103) of anterior pituitary function. The mean margin dose was 19.1(6.2) Gy. Larger distance from the center of the stalk to the tumor margin isodose was a positive predictor (adjusted odds ratio [aOR] = 1.162 [1.046-1.291], P = .005), while pre-SRS hypopituitarism (aOR = 0.646 [0.405-1.031], P = .067) and larger treatment volume (aOR = 0.965 [0.929-1.002], P = .061) were near negative predictors of the primary outcome. An interaction between the treatment volume and center stalk to margin isodose distance was found (aOR = 0.980 [0.961-0.999], P = .045). Center stalk to margin isodose distance had an AUROC of 0.620 (0.557-0.693), at 3.95-mm distance. For patients with treatment volumes of <2.34 mL, center stalk to margin isodose distance had an AUROC of 0.719 (0.614-0.823), at 2.95-mm distance. CONCLUSION: Achieving a distance between the center of the pituitary stalk and the tumor margin isodose ≥3.95 mm predicted anterior pituitary function preservation. For smaller treatment volumes <2.34 mL, the optimal distance was ≥2.95 mm. This may be modifiable during trans-sphenoidal resection to preserve pituitary function.
