Pituitary adenomas: long-term results for radiotherapy alone and post-operative radiotherapy.

Purpose: Analysis of prognostic factors and long-term results of treatment of pituitary adenomas.

Methods And Materials: The study involved a retrospective review of outcome in a series of 268 patients with pituitary adenomas, treated at the Queensland Radium Institute from January 1962 to December 1986. The study population included 108 patients treated with radiotherapy alone and 160 patients treated by surgery and post-operative radiotherapy. In each group, univariate and multivariate analyses were conducted of possible prognostic factors including age, sex, performance status, tumor type, tumor extent, visual disturbance, radiotherapy dose, and field size.

Results: For radiotherapy alone, the 10-year progression-free survival rate was 60%, and overall tumor control was obtained in 77%. Univariate analysis suggested that tumor type and radiotherapy field size were of prognostic significance. Multivariate analysis confirmed that Prolactinoma subtype and increasing radiotherapy field size were independently predictive of reduced progression-free survival. Long-term visual complications occurred in 1% of patients treated by radiotherapy alone. In patients treated by surgery and post-operative radiotherapy, the 10-year progression-free survival rate was 77%, and overall tumor control was achieved in 83%. Univariate analysis suggested that tumor type, completeness of surgical excision, and radiotherapy dose were predictive of outcome. However, on multivariate analysis, only the extent of surgical excision predicted prognosis independently. Long-term visual sequelae were noted in 3% of patients treated by surgery and post-operative radiotherapy.

Conclusion: Both radiotherapy alone and post-operative radiotherapy are effective in long-term control of pituitary adenomas, and produce acceptably low complication rates.