Surveillance Imaging Strategies for Pituitary Adenomas: When, How Frequent, and When to Stop

To describe a practical approach of when and how often to perform imaging, and when to stop imaging pituitary adenomas (PAs). A literature review was carried out and recommendations provided are derived largely from personal experience. Magnetic resonance imaging is the mainstay imaging modality of choice in the assessment, treatment planning, and follow-up of PAs. These adenomas are discovered incidentally during imaging for a variety of unrelated conditions, because of clinical symptoms related to mass effects on the adjacent structures, or during workup for functional alterations of the adenoma. Imaging is also used in the preoperative and postoperative phases of assessment of PAs, for surgical and radiotherapy planning, for postoperative surveillance to assess for adenoma stability and detection of adenoma recurrence, and for surveillance to monitor for adenoma growth in unoperated PAs. Currently, because there are no evidence-based consensus recommendations, the optimal strategy for surveillance imaging of PAs is not clearly established. Younger age, initial adenoma size, extrasellar extension, mass effect, cavernous sinus invasion, functional status, histopathologic characteristics, cost considerations, imaging accessibility, patient preference, and patient contraindications (eg, implanted metallic devices and patient claustrophobia) are all important factors that influence the strategy for surveillance imaging. This review provides a practical approach of performing surveillance imaging strategies for PAs that should be individualized based on clinical presentation, history, adenoma morphology on imaging, and histopathologic characteristics.