Evaluation of clinical, radiological and biochemical changes in response to somatostatin receptor analog after surgery in acromegaly patients

Purpose: In predicting the response to somatostatin receptor analogues (SSA) in patients diagnosed with acromegaly in the third month and first year follow-up after surgery, at the time of diagnosis; To investigate whether age, gender, growth hormone, Insulin-like growth factor-1 values and tumor volume, hyperostosis frontalis interna (HFI) measurements and T2-weighted (T2W) magnetic resonance images (MRI) contribute to the outcome. Materials and Methods: Patient anamneses, demographic data, biochemical laboratory results, treatments they received, pituitary MRI reports before the operation, colonoscopy reports, pathology reports, echocardiography and various ultrasonography reports reviewed retrospectively of 60 patients diagnosed with acromegaly who were followed in our Endocrinology and Metabolism Diseases polyclinic of Gaziantep University Sahinbey Training and Research Hospital between 2012 and 2022. By evaluating the latest biochemical parameters 3 months and 1 year after the operation, patients in early remission, late remission and non-remission patients were identified. In addition, HFI was measured and tumor volume was calculated; (T2W) pituitary MRI was re-evaluated and whether there was a statistical relationship between the semiquantitative values obtained from these measurements and demographic results was investigated with bivariate and multivariate statistical analyses. Result: Of the 60 patients included in the study, 31 were women (51.67%) and 29 were men (48.33%). The age of the patients at diagnosis ranged between 18 and 64 years, and the average age was calculated as 39,3 years. All 60 patients had at least one pituitary surgery. When the pituitary MRI of the patients at the time of diagnosis were re-evaluated on the T2 sequence, 19 of the patients (31.67%) were interpreted as hypointense, 27 (45%) were isointense, and 14 (23.33%) were interpreted as hyperintense. There were 38 patients using SSA treatment, 12 of them were receiving lanreotide (31.57%) and 26 were receiving ocreotide (68.43%). In the patient group that was hypointense according to pre-operative (T2W) pituitary MRI, they were more likely to achieve remission at both the 3rd month and the first year (p=0.001; p=0.001). According to preoperative (T2W) pituitary MRI, remission was not achieved at the end of the third month in the patient group that was isointense (p<0.001). Remission status was compared with the Knosp classification, which was evaluated according to the extent of the tumor to the cavernous sinus, and patients with lower Knosp classification scores were more likely to achieve remission at the third month and first year (p=0.035; p=0.04). At the end of the first year, a statistically significant difference was found between patients who were not in remission and diabetes mellitus (p<0.008). Of the patients who were not in remission at the end of the first year, 17 (56.7%) had diabetes mellitus and early or late remission could not be achieved. Conclusion: In our study, clinical, radiological and biochemical parameters that predict response to SSA treatment after the operation were examined; No significant difference was found between gender, age at diagnosis, tumor volume and HFI measurements and response to SSA treatment. In the postoperative period, a significant relationship was found between the decrease in GH and IGF-1, MRI hypointensity, low Knosp classification score, and the absence of diabetes mellitus are good response to SSA treatment.