The main objective of this thesis is to evaluate the results of radiation therapy among patients with pituitary adenomas with regard to treatment efficacy, side-effects and quality of life.

1
To determine the role of radiation therapy in residual non-functioning pituitary adenoma in relation to local control, side effects and overall survival, as reviewed in the literature and evaluated in our series. Chapter 2

2
To evaluate the influence of radiation therapy on cognitive function and quality of life in patients with non-functioning pituitary adenoma.
Chapter 3

3
To establish the incidence of RON in acromegaly and its risk factors in the literature. This side-effect has been evaluated in irradiated acromegalic patients in the University Medical Center Groningen and is presented in a complete updated review. Chapter 4-5

4
To establish the incidence of RON in non-functioning pituitary adenomas in the literature in addition to our own series, presented in the first available review published on this subject. Chapter 6

5
To investigate the diagnostic role of new-imaging techniques: how are Positron Emission Tomography (PET) imaging characteristics affected by surgery and radiation therapy for pituitary adenoma. Chapter 7

6
Finally, we investigated whether the position of head and neck cancer
patients with conformal non-coplanar radiation techniques could be determined from portal images of oblique radiation beams. Chapter 8