Gamma knife radiosurgery for medically and surgically refractory prolactinomas

Area of Science:

• Neurosurgery
• Endocrinology
• Radiation Oncology

Background:

• Prolactinomas are pituitary tumors typically managed with medical or surgical therapies.
• Gamma knife radiosurgery (GKRS) is an option for prolactinomas refractory to standard treatments.
• Limited data exists on GKRS efficacy for medically and surgically resistant prolactinomas.

Purpose of the Study:

• To evaluate the effectiveness of GKRS in patients with prolactinomas that did not respond to prior medical or surgical interventions.
• To identify factors associated with successful treatment outcomes after GKRS for prolactinomas.

Main Methods:

• A retrospective review was conducted on patients with prolactinomas treated with GKRS.
• Patients included had failed previous medical and/or surgical therapies and had at least one year of follow-up.
• Endocrine and imaging outcomes were analyzed.

Main Results:

• Twenty-six percent of patients achieved clinical remission (normal prolactin levels) after GKRS.
• Remission was significantly linked to smaller tumor volume (<3.0 cm³) and absence of dopamine agonist therapy at treatment.
• Long-term volumetric tumor control was achieved in 89% of patients, with complications including new pituitary hormone deficiencies (28%) and cranial nerve palsy (7%).

Conclusions:

• GKRS provides a modest clinical remission rate for refractory prolactinomas but achieves high rates of volumetric control.
• The complication profile of GKRS in this series was acceptable.
• GKRS is a viable treatment option for refractory prolactinomas, particularly in patients with smaller tumors and those not on dopamine agonists.