Pituitary and pituitary region tumors: Viewpoint—fractionated radiation therapy

Abstract

Pituitary region tumors, including functional and nonfunctional pituitary adenomas, meningiomas, and craniopharyngiomas, are important and distinct benign entities that have both distinct and shared management issues. It is important to have multidisciplinary management to achieve optimal outcomes for patients with pituitary region tumors. These patients may enjoy normal or near-normal life spans but may have lifelong tumor-related or iatrogenic morbidity that can include visual problems (visual field cuts and gaze palsies), endocrine insufficiencies that require monitoring and replacement, and neurocognitive deficits that impair important capabilities and quality of life. Because surgical management and medical management may not suffice to prevent morbidity from tumor growth or hormonal secretion, irradiation is an option that must be considered as part of multidisciplinary management. For tumors in this region, fractionated radiation therapy has a long and successful track record in controlling tumor growth and may often be a better choice than radiosurgery. Radiotherapy's small daily doses exploit the radiobiological advantages of reoxygenation, redistribution, and repair of DNA damage (which increases the dose that can be given to normal tissues). As most tumors in this location are slow-growing, benign tumors, repopulation of the tumor being irradiated during a course of radiotherapy treatment is not a concern. Current focused radiation therapy approaches using image guidance and attempting to spare normal tissues such as the hippocampi may result in an improved risk-benefit ratio for patients. Randomized clinical trials to document improved outcomes for patients treated with these advanced technologies or alternative approaches such as proton beam therapy are lacking, as are trials comparing radiosurgery and fractionated radiotherapy.​