Completely Resected Pituitary Macroadenomas Have a Low Risk of Long-Term Radiographic Progression

Background: In 2017, the FDA issued a warning regarding the risk of chronic retention of gadolinium in several body tissues, including brain, following the administration of gadolinium-based contrast agents. This risk is heightened in patients requiring multiple lifetime doses, such as those who have undergone pituitary adenoma surgery. In this study, we assessed the long-term risk of radiographic recurrence of pituitary macroadenomas in an attempt to define patients at low risk for progression, in whom fewer surveillance scans may be warranted.

Methods: The records of all patients undergoing endoscopic endonasal transsphenoidal resection of pituitary macroadenomas between 2007 and 2011 at our institution were reviewed. Only patients with more than 3 years of clinical and radiographic follow-up were included.

Results: 45 patients with at least 3 years of follow-up were identified, 33 of whom had at least 5 years of follow-up. The average age was 53 ± 18 years. Twenty patients were male, 26 were female. Thirty-two had non-functioning adenomas (average diameter 2.5 ± 1.3 cm), and 14 had hormone-secreting tumors (average diameter 2.4 ± 0.7 cm). The most common presenting symptoms were visual loss (42%), endocrinopathy (29%), and headache (16%).

Among patients with non-functioning tumors, tumor resection was complete in 18. One-hundred percent of these patients had no evidence of tumor recurrence 3 years after surgery. More than 5 years of follow-up was available for 10 of these patients (average 8 ± 1.6 years). No tumor recurred over this time period. In contrast, only 8/12 (66%) patients with subtotal resections and no additional treatment remained progression-free at 3 years. This was significantly less than patients with complete resections (X2 = 4.28, p = 0.04). Four patients with subtotal resection and stable imaging at 3 years were followed more than five years (average ± 2 years). Two of these demonstrated progression, and two did not.

Among the 13 patients with functioning tumors, only 4 (26%) had complete resections. All 4 had greater than 5 years of follow-up demonstrating no radiographic recurrence. In contrast, of 7 patients with subtotal resections and no additional treatment, 5 (66%) demonstrated stable tumor size at 3 years after surgery. Four of these patients had greater than 5 years of imaging follow-up (average 8.5 ± 2 years), and all demonstrated stability of their lesions.

Conclusions: These preliminary results suggest that patients with completely resected pituitary lesions are at a low risk of progression and surveillance imaging may safely be widely spaced. In contrast, those with subtotal resections require more frequent surveillance imaging.