gms | German Medical Science

Objective: Growth hormone (GH) producing adenomas are still challenging. Long term sequelae of high GH levels are severe and surgical resection is the primary treatment option. The use of intraoperative MRI increases extent of resection and it seems to be beneficial for transsphenoidal pituitary surgery. We have evaluated the clinical outcome of patients with acromegaly treated with iMRI assisted transsphenoidal pituitary surgery.

Methods: We conducted a retrospective analysis of patients treated by iMRI assisted transsphenoidal surgery at our department between 2012 and 2020. A total number of 52 patients (54 surgeries) with acromegaly was selected for the further analysis. Detailed volumetric tumor measurement before surgery, intraoperatively and three months after surgery was performed (Brainlab, Elements). Pituitary adenomas were graded according to Knosp classification. Additionally, demographic data, clinical symptoms as well as complications and endocrine outcome were evaluated.

Results: Out of 54 pts, 68.5% (N=37) were graded as Knosp 0-2. Mean age was 45 years and mostly male patients were treated (59.3%, N=32). Median tumor volume was 1.47 cm3 (ratio 0.06-39.1 cm3). Endoscopic surgery was performed in 48.1% (N=26). Recurrent adenoma was treated in 14.8% (N=8). Biochemical remission was achieved in 62.9% (N=22/35) and it was significantly associated with lower Knosp grade (p=0.009). We found no significant association between remission and surgical technique (p=0.122). Additional tumor resection after iMRI was performed in 26.4% (N=14/53) and was significantly associated with more infiltrative growth pattern (p=0.019). We found no significant difference between additional resection and surgical technique (p=0.866). Revision due to cerebrospinal fluid fistula was performed in 7.4% (N=4). New permanent diabetes insipidus was found in 3.7% (N=2).

Conclusion: Intraoperative MRI might be a helpful tool in the treatment of acromegaly in order to achieve gross total resection and biochemical remission of the disease independently on surgical technique. Adenomas infiltrating cavernous sinus seem to profit from iMRI, however it might help to achieve this goal even in adenomas without invasive growth pattern treated by endoscopic technique.