Endocrine Abstracts

Acromegaly is a rare disease with high morbidity and mortality associated with excessive secretion of growth hormone due to adenoma of somatotroph cells in the pituitary gland. In patients with acromegaly, residue may remain after surgical treatment, and disease control is attempted with surgery, medical treatment or radiotherapy for these patients. Pituitary imaging, IGF-1 and GH measurement are used in the follow-ups. Dynamic Contrast Enhancement perfusion MRI provides information about tissue properties at the microvascular level. It provides information and comparison about normal-neoplastic tissue permeability. K-trans transfer constant and increases in neovascularity The K-trans demonstrated by this MRI is the transfer constant and increases in neovascularity. Ve indicates the fractional volume of the extracellular space, increasing in necrosis. Kep is the velocity constant. The IAUC is a data on the interstitial area under curve, fractional blood volume. Since there are also studies showing that GH increases neovascularity, we thought that evaluation with Dynamic Contrast Enhancement (DCE)-MRI could be a clearer guide to the clinician in terms of clarifying the adenoma type during the diagnosis and follow-up of patients with acromegaly.

Material Method: A total of 31 patients including postoperative residual adenoma, 16 diagnosed with non-functioning adenoma (NFA), and 15 diagnosed with acromegaly, were included in the study. MRI Examination was performed with a GE 750W 3.0T MR scanner (2013, GE Healthcare, Milwaukee, WI) using a 16-channel GEM Quiet HNU head coil. Precontrast sagittal and coronal T1 and T2 weighted, postcontrast coronal coronal and sagittal T1, coronal FIESTA sequences after DCE-MRI were taken. MRI images were evaluated by a radiologist with 20 years of experience in neuroradiology. The radiologist was blind to the patients’ pathology.

Results: Although the K-transAdenoma and KepAdenoma values were higher in the patients’ residual adenomas, the madian values were higher in the acromegaly residues, but no statistically significant difference was found (P>0.05). However, a positive correlation was found between the GH values of GH secreting adenomas and K-transAdenoma and KepAdenoma values (r=0.552, r=0.605, P<0.05, respectively).

Discussion: DCE-MRI may be a promising method in the diagnosis and follow-up of acromegaly, since the median values are high in acromegaly residues, although there is no statistical difference, and there is also a positive correlation between GH levels and Ktrans and Kep values in GH-secreting adenomas. Considering the available data together with the relationship between GH and neovascularization, it seems promising to carry out further studies by enlarging the sample.