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Updated: Jun 4, 2026
Endoscopic Endonasal Trans-sphenoidal Approach: Minimally Invasive Surgery for Pituitary Adenomas
Published on: January 17, 2018
Gamma knife radiosurgery for patients with prolactin-secreting pituitary adenomas
Shota Tanaka1, Michael J Link, Paul D Brown
1Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Objective:
To evaluate the efficacy of stereotactic radiosurgery (SRS) for patients with prolactin (PRL)-secreting pituitary adenomas that were refractory to medical management.
Methods:
Retrospective review of 22 patients treated with SRS from 1994 until 2006. All patients were either intolerant or their tumors were unresponsive to dopamine agonist therapy. Nine patients (41%) had undergone prior transsphenoidal surgery. The median serum PRL concentration before SRS was 88.4 ng/mL (range, 25-943). The median treatment volume was 2.2 cm(3) (range, 0.4-29.0); the median margin radiation dose was 25 Gy (range, 16-30). The median endocrinologic follow-up was 60 months (range, 16-129).
Results:
Tumor control after SRS was 100%. Serum PRL concentration was significantly lower (median, 28.4 ng/mL) (P = 0.006) at last follow-up, but the 4-year actuarial rate of biochemical remission off medications was only 17%. No tested variable was associated with biochemical remission off medications. Overall, four patients (18%) had biochemical remission off medications and clinical improvement, three patients (14%) had normal serum PRL concentrations and clinical improvement on dopamine agonist therapy, seven patients (32%) had improved symptoms off medications but continued to have elevated serum PRL levels, and eight patients (36%) continued to be symptomatic with elevated PRL levels either on (n = 3) or off (n = 5) dopamine agonist therapy. The incidence of new anterior pituitary deficits was 42% at 4 years.
Conclusions:
SRS was effective in controlling tumor growth for patients with PRL-secreting pituitary adenomas, and the majority of patients were clinically improved.
Insights
Stereotactic radiosurgery (SRS) effectively controlled prolactin (PRL)-secreting pituitary adenomas refractory to medical treatment. While tumor growth was managed, biochemical remission off medication was limited, though most patients showed clinical improvement.
Area of Science:
- Neurosurgery
- Endocrinology
- Radiation Oncology
Background:
- Prolactin (PRL)-secreting pituitary adenomas often require medical management with dopamine agonists.
- Tumors refractory to or patients intolerant of medical therapy present a treatment challenge.
- Stereotactic radiosurgery (SRS) is an option for select cases.
Purpose of the Study:
- To evaluate the efficacy of SRS for managing PRL-secreting pituitary adenomas resistant to dopamine agonist therapy.
- To assess tumor control, hormonal remission, and clinical outcomes post-SRS.
- To identify factors influencing treatment success.
Main Methods:
- Retrospective review of 22 patients with PRL-secreting pituitary adenomas treated with SRS.
- Patients had failed or were intolerant to dopamine agonist therapy; some had prior surgery.
- Median follow-up was 60 months, with analysis of tumor volume, radiation dose, and serum PRL levels.
Main Results:
- 100% tumor control was achieved with SRS.
- Serum PRL levels significantly decreased, but the 4-year remission rate off medication was 17%.
- 42% incidence of new anterior pituitary deficits at 4 years; most patients experienced clinical improvement.
Conclusions:
- SRS is effective for controlling tumor growth in PRL-secreting pituitary adenomas.
- While SRS improves symptoms in most patients, achieving biochemical remission off medication is challenging.
- Careful consideration of potential pituitary deficits is necessary.
