Pituitary Society Delphi consensus on the role of radiotherapy for pituitary adenomas

Radiotherapy is used as second- or third-line treatment after transsphenoidal surgery for both functioning and nonfunctioning pituitary adenomas. Improved precision delivery may reduce side effects, but use overall has declined, partly due to improved surgical technique and advances in medical therapy, partly reflecting a shift from fractionated radiotherapy to stereotactic radiosurgery in appropriately selected patients, and also due to lack of clear, evidence-based guidelines. Questions remain regarding radiotherapy indications, optimal timing, choice of technique, and follow-up for efficacy and side effects. The aim of this Delphi panel was to establish expert consensus in these areas.

The Pituitary Society Steering Committee conducted a modified two-round Delphi panel with 29 international experts from five continents, including neuroendocrinologists, neurosurgeons and radiation oncologists.

Among the 26 initial statements, 22 (84.6%) reached agreement after Round 1. Four statements were reconsidered in Round 2, together with an additional question, after which 24 of 27 (88.9%) reached consensus. Panelists agreed that radiotherapy indication and timing should be assessed by expert multidisciplinary tumor boards, including a radiation oncologist, with the technique determined according to patient and adenoma characteristics. They emphasized controlling hormonal secretion while waiting for maximal radiotherapy efficacy in functioning adenomas. Long term follow-up > 10 years is required to assess for delayed efficacy, recurrence and side effects, although panelists agreed on the relatively low medium-term risk with modern techniques.

Modified Delphi panel provides practical guidance regarding indications, timing, choice of technique and long-term follow-up of radiotherapy in pituitary adenomas. Modern techniques appear as effective and potentially safer vs. previous ones. Further long-term comparative data are needed.