Endocrine Abstracts

Objectives: First-generation SMSa are the medical treatment of choice in the management of acromegaly, mainly as adjuvant treatment of pituitary surgery when normal IGF-1 is not obtained or as primary treatment in selected patients. The main objective of this study is to evaluate regular pituitary MRI follow-up of acromegalic patients treated with SMSa as adjuvant treatment of pituitary surgery. The secondary objective is to compare the anti-tumoral effect of SMSa in post-operative period to the effect observed during primary treatment of acromegalic patients.

Patients and Methods: In a monocentric, retrospective study we included all acromegalic patients treated with SMSa after a pituitary surgery or first-line therapy, and regularly followed by MRI scans for at least 3 years. The height of pituitary adenomas or post-operative remnants was measured along the coronal plane, perpendicularly to the optic chiasm, and all MRI scans are seen by the same neuro-radiologist.

Results: We included 27 patients (11 women, 16 men, mean age 39.5 ± 12.2 years) treated with SMS a after surgery. The post-operative evaluation revealed persistent GH/IGF-1 hypersecretion (GH = 4.2 ± 9.9 ng/ml, IGF-1 = 175 ± 74% ULN) and adenoma remnants (9.25 ± 5.34 mm). After 6.1 ± 4.5 years of SMSa treatment,the adenoma height did not decrease significantly in controlled (n = 11, 8 ± 5.0 vs 6.5 ± 3.5mm, ns) or uncontrolled (n = 16, 9.78 ± 5.54 vs 9.35 ± 4.71mm, ns) patients, with 20 adenoma remnants remaining stable. A significant increase (≥ 2 mm) of adenoma height was observed in a patient with acromegaly revealed by pituitary apoplexy and with histological aggressiveness criteria. Eighty three patients (32 men, 51 women, mean age 50 ± 12 years) with mean GH = 19.3 ± 25.6 ng/ml, IGF-1 = 284 ± 110 % ULN and pituitary adenoma height = 12.9 ± 4.7 mm were primary treated with SMSa : adenoma height decreased significantly in controlled patients (11.9 ± 4.8 mm vs 9.6 ± 3.3 mm, P < 0.001) after 8.9±4.9 years, and in partially responders (13.6 ± 4.5 mm vs 11.5 ± 4.5 mm, P < 0.001) after 2.0 ± 1.6 years. Compared to the patients post-operative treated with SMSa, a greater anti-tumor effect was observed when SMSa was primary administered (2.20 ± 3.03 mm vs 0.75 ± 2.65 mm, P < 0.02).

Conclusion: This clinical study shows that regular post-operative MRI monitoring of adenoma remnants does not seem necessary during SMSa treatment, but it remains indicated for rare patients with atypical adenoma and histological aggressiveness criteria, and confirms that first-generation SMS a have an anti-tumoral effect significantly lower in adjuvant treatment than in primary treatment.