Pituitary Neuroendocrine Tumors (PitNETs)/Pituitary Adenomas

Pituitary neuroendocrine tumors (PitNETs)/pituitary adenomas are common neoplasms of the brain estimated to represent approximately 15–20% of all intracranial neoplasms. Clinically nonfunctioning PitNETs/pituitary adenomas account for 25–30% of pituitary adenomas, while secreting PitNETs/pituitary adenomas account for the rest. PitNETs/pituitary adenomas are found incidentally on brain computed tomography (CT) or magnetic resonance imaging (MRI) scans in approximately 20–40% of cases. Other patients present with visual symptoms from tumor compression of the optic chiasm, headache, or hypopituitarism. Functioning tumors, or those that secrete or produce excess pituitary hormones, often present with symptoms related to hormone hypersecretion. Treatment of PitNETs/pituitary adenomas can include a combination of medical management, surgical resection, and radiation therapy. Radiation is typically reserved for subtotal resections, recurrence, and secreting PitNETs/pituitary adenomas refractory to surgery and medical management. When radiation therapy is needed for nonfunctional PitNETs/pituitary adenomas, fractionated doses of 45–50.4 Gray (Gy) and radiosurgery doses of 15 Gy should be used. Secreting PitNETs/pituitary adenomas require higher doses, either 50.4–54 Gy for a fractionated course or at least 20 Gy for stereotactic radiosurgery (SRS). Radiation therapy provides excellent 10-year local control rates approaching 90–95%.