Endocrine Abstracts

Background: The role of post-operative radiotherapy (RT) in the treatment of non-functioning pituitary adenomas (NFA) remains controversial. We compared the difference in outcome between patients receiving transsphenoidal surgery (TSS) alone and TSS plus RT in 93 patients treated for NFA between 1986 and 2005. 64 (69%) had TSS alone whilst 29 (31%) received TSS plus RT (45GY, 25Fr, 3 field). All patients were followed up by CT and then MRI scans repeated at increasing intervals. Tumor recurrence was defined as a significant increase in pituitary size on CT/MRI.

Results: Follow up (median + range) was 6.4 (0.1–17.8) years in TSS and 5.7 (1.8–18.7) years in TSS+RT groups. Tumor recurrence occurred in 14 (22%) TSS at 4.1 (1.6–10.3) years and 2 (7%) TSS+RT at 6.3 and 14 years. In TSS group the recurrence rates were 18% at 5 years and 41% at 10 years. Only 4 of 14 recurrences in TSS group involved suprasellar extension (SSE; 3 in era of CT for post-op scan) and recurrence was intrasellar in the remainder; only one SSE caused worsening of visual field defect and this improved after repeat surgery. Second treatment in the TSS group included RT alone (n=10), repeat surgery plus RT (n=2), repeat surgery alone (n=1) and observation alone (n=1). Both TSS+RT received repeat surgery. Regarding endocrine replacement, 37.5% of TSS required 3 or more hormone products, compared with 62% in TSS+RT.

Conclusion: Our results confirm that NFA recurrence after TSS is reduced in patients treated with RT, but show no evidence of harm prior to treatment of recurrence in the TSS only patients. Given the increased morbidity and cardiovascular risk associated with hypopituitarism, and recent evidence that dopamine agonists may inhibit tumor recurrence, we suggest that this expectant approach as regards RT is justifiable and potentially advantageous.