Long-term results of radiation therapy for pituitary adenoma

Purpose. Local control for pituitary adenomas treated with external beam ra diation therapy was retrospectively analyzed to evaluate the efficacy of ra diation. Materials and methods. Thirty-eight patients treated with radiation therapy between 1979 and 1994 were analyzed. The median age was 46. Nineteen newly diagnosed tumors were treated with surgery and radiation therapy, while th e others were recurrent cases. Twenty-two tumors were non-functioning, whil e 10 produced growth hormone (GH) and three each were prolactin-, and adren ocorticotropic hormone (ACTH)-producing tumors. The median radiation dose w as 50 Gy in 25 fractions. Results. Non-functioning adenomas and prolactin-producing adenomas were com pletely controlled, judging from the absence of tumor progression on neuroi maging studies and clinical symptoms, and normalization of the serum prolac tin level (< 25 ng/ml). On the other hand, local control was obtained in on ly one of the 3 patients with ACTH-producing adenomas, and the control rate at 10 years was only 46% for GH-producing adenomas. Panhypopituitarism dev eloped in 35% of the patients after radiation therapy. No other serious com plications were noted. Conclusion. Non-functioning pituitary adenomas and prolactin-producing aden omas were well controlled with external radiation therapy combined with sur gery. However, dose escalation might be necessary to control GH- or ACTH-pr oducing tumors. It is important to replace corticosteroid hormone and thyro id hormone in many patients.