Pituitary adenoma: the efficacy of radiotherapy as the sole treatment

The management of patients with pituitary adenomas by radiotherapy alone, using modern techniques of evaluation and current standards of treatment, has not been examined. This is a retrospective review of 29 such patients with nonfunctional or prolactin secreting pituitary macroadenomas. Patients were analyzed by visual fields, hormone levels, and CT scans. All but one patient received a tumor dose of 4500 cGy in 4 to 5 weeks. The tumor was controlled in 26 of 28 (93%) patients for an observed period of 3 to 14 years. Seventeen of 21 (81%) patients with visual impairment experienced normalization or improvement, and seven of ten (70%) patients with hyperprolactinemia achieved normalization of their serum prolactin levels. Post-treatment CT scanning revealed persistent tumor in nine of 17 patients despite clinical improvement. We conclude that: (a) radiotherapy is an effective treatment for these tumors; (b) doses need not exceed 4500 cGy in 25 fractions; (c) radiation is effective for improving vision; (d) radiation can normalize hyperprolactinemia; and (e) tumor regression is variable and unrelated to observed symptom regression.