Postoperative radiation therapy for pituitary adenoma

Area of Science:

• Endocrinology
• Radiation Oncology
• Neurosurgery

Background:

• Pituitary adenomas are common tumors requiring effective treatment strategies.
• Postoperative radiation therapy (RT) is a key modality for managing residual or recurrent pituitary adenomas.
• Understanding prognostic factors and dose-response relationships is crucial for optimizing RT efficacy and minimizing toxicity.

Purpose of the Study:

• To evaluate the efficacy of postoperative RT in pituitary adenoma patients.
• To identify prognostic factors influencing local control probability.
• To determine the dose-response relationship and treatment sequelae of RT.

Main Methods:

• Retrospective analysis of 75 pituitary adenoma patients treated with postoperative RT.
• Doses ranged from 48-60 Gy (median 50 Gy) with conventional fractionation.
• Long-term follow-up exceeding 5 and 10 years for a significant proportion of patients.

Main Results:

• Five- and 10-year local control rates were 87.1% and 85.0%, respectively.
• Favorable prognostic factors included younger age, tumor volume < 30 cm³, and absence of prolactin secretion.
• No significant local control improvement was observed with doses > 50 Gy; hypopituitarism was the most common sequela.

Conclusions:

• Postoperative RT up to 50 Gy is effective for pituitary adenoma, excluding large prolactinomas.
• Large prolactinomas (> 30 cm³) exhibit poor local control with conventional RT doses.
• Stereotactic radiosurgery or radiation therapy may be superior options for large, difficult-to-control prolactinomas.