Radiation therapy of non-functioning pituitary adenomas

Abstract

Radiation therapy is a well-established treatment in pituitary adenomas. The aim of the treatment is to control the tumor cell proliferation and, in endocrine tumors, to reduce the hypersecretion. These goals should be achieved with minimal injury to the surrounding normal tissue. The use of radiation therapy in the treatment of pituitary adenomas was first described in 1909 for a patient with acromegaliy (Gramegna et al. 1909). Although there are no randomized studies comparing the role of radiotherapy with surgery or medical management, the clinical experience accumulated over a century, as well as many retrospective and prospective studies, clearly demonstrated the importance of this therapy in the management of pituitary adenomas. However, many problems concerning patients' selection and radiation treatment technique remain unsolved. The goal of radiation treatment planning should be conformal coverage of the tumor with maximal sparing of the surrounding normal tissue. A total dose of 45–50.4 Gy in 1.8 Gy/fraction, 5x/week is generally recommended. The optimal irradiation technique is the stereotactic fractionated radiotherapy, combined in special cases with intensity modulated radiotherapy. Radiosurgery may be indicated in individual cases. A high rate of tumor control with a very low rate of side-effects is achieved in 85–95% of patients. The rate of side effects is low. The goal of the presentation is to discuss the advantages of new technological advances in radiation therapy and the consequences for the treatment of non-functioning pituitary adenomas.