Radiotherapy and Mortality in Pituitary Adenomas

Background

Pituitary adenomas (PA), comprising 10–20% of intracranial tumors, are classified as functioning and non-functioning and are further divided by size. Non-functioning tumors cause mechanical symptoms while functioning ones result in hormonal hypersecretion syndromes. Initial treatment involves surgery, with medical treatment for prolactinomas. Radiotherapy (RT) is employed as an adjuvant treatment, with various modalities including conventional, stereotactic radiosurgery (SRS), and fractionated stereotactic RT (FSRT). Although effective, RT is associated with complications and toxicities such as hypopituitarism, optic neuritis, secondary CNS tumors, and neurocognitive deficits.

Aim

Describe the information on mortality from radiotherapy as treatment of functioning PA.

Methods

A PubMed search spanning 2000–2017 was conducted for articles on pituitary RT.

Results

Conventional RT entails high-energy radiation over multiple sessions, while SRS delivers precise high doses in a single session. FSRT offers enhanced precision using a linear accelerator, delivering multiple doses. Optic structure proximity and tumor volume dictate RT modality. Studies have shown SRS and FSRT's efficacy in tumor and endocrine control, with variable risks and complications. Mortality rates in pituitary adenomas treated with RT have been evaluated, revealing complexities. Acromegaly, associated with increased mortality due to cerebrovascular disease, may result from RT. Irradiation of non-functioning pituitary macroadenomas also elevates cerebrovascular risk, while radiotherapy-induced hypopituitarism is associated with increased cardiovascular mortality. RT-induced damage is attributed to microvascular lesions and arteriolar changes.

Conclusion

Modern techniques mitigate complications, and although safer, long-term studies are needed. Multidisciplinary evaluation guides the treatment decision, optimizing efficacy and minimizing risk, ultimately improving the patient's quality of life.