Long-Term Outcomes After CyberKnife Radiosurgery for Nonfunctioning Pituitary Adenomas

Area of Science:

• Neurosurgery
• Radiation Oncology
• Endocrinology

Background:

• Nonfunctioning pituitary adenomas (NFPAs) are often managed with stereotactic radiosurgery (SRS).
• Previous studies on SRS for NFPAs have been limited by small sample sizes and short follow-up periods.
• Long-term outcomes of SRS for NFPAs require further investigation.

Purpose of the Study:

• To evaluate the long-term efficacy and safety of SRS for managing NFPAs.
• To assess tumor control rates, incidence of new-onset hypopituitarism, and visual outcomes after SRS.
• To identify risk factors associated with adverse events following SRS for NFPAs.

Main Methods:

• Retrospective review of 178 patients with NFPAs treated with CyberKnife radiosurgery.
• Assessment of tumor control, new-onset hypopituitarism, and new visual disorders.
• Analysis of progression-free survival and cumulative incidence of hypopituitarism over extended follow-up periods.

Main Results:

• High tumor control rates observed, with 10-year progression-free survival at 93.04%.
• New-onset hypopituitarism occurred in 16.9% of patients, with cumulative incidence reaching 15.25% at 10 years.
• Higher biological effective dose (>140 Gy) and single fraction equivalent dose (>16.0 Gy) were risk factors for hypopituitarism; larger tumor volume (>2.5 mL) was associated with visual disorders.

Conclusions:

• Stereotactic radiosurgery is an effective and relatively safe treatment for primary and residual/recurrent NFPAs.
• Long-term tumor control is excellent, but endocrine surveillance is crucial due to the risk of hypopituitarism.
• Risk stratification based on radiation dose and tumor volume can help personalize treatment and manage potential adverse effects.