Postoperative Use of Dopamine Agonist in Controlling the Residual Mass in Non Functioning Pituitary Adenoma

Abstract

Background: Non-functioning pituitary adenoma (NFPA) is a challenging tumor. It is usually reached to a large size before it is clinically manifested. Operative interference is the first option in treatment of large NFPA causing compressive manifestations but with frequent postoperative residual masses that is usually required additional treatment. Postoperative radiotherapy carried frequent side effects which open the door for postoperative medical treatment with dopamine agonist (DA) drugs based on the fact that these tumors have a variable amount of dopamine receptors. Lack of randomized, placebo-controlled trials prevents any conclusion on the efficacy of this drug. Its role in controlling postoperative proliferation and decreasing the rate of recurrence of NFPA is still questionable. Objective: Efficacy of bromocriptine (dopamine agonist (DA) drug) in reducing or preventing the re-growth of non-functioning pituitary adenoma NFPA after surgery. Methods: In this study, we examined the outcome of treating NFPA after surgery, with bromocriptine (dopamine agonists drug). This study was a retrospective review of consecutive patients that were treated by the authors at Assiut University Hospital between 2012-2018. All patients had postoperative Bromocriptine in a dose of 2.5 mg twice daily. Results: Thirty two patients were included in this study after they had surgery for NFPA. All patients had a residual mass documented by the immediate post operative MRI. After 6 months of postoperative bromocriptine treatment, and with comparing to immediate post operative images, eleven patients (34%) had mass reduction, thirteen patients (41%) of their residual masses remained unchanged and eight patients (25%) of the mass showed slight increase in size but not required re-surgery. After two years and throughout the follow up period, seven patients (22%) (all were males) had complete disappearance of the mass; ten patients (31%) had more reduction of the size of the mass (two of them were males) and four patients (13%) of the mass remained unchanged (none of them were males) and eleven patients (34%) had increase of the mass and they required re-surgery (two of them were males). Conclusion: Bromocriptine (DA drug) can play a role in reducing the size or preventing the re-growth of non-functioning pituitary adenoma after surgical debulking. Males showed noticeable response comparing to females. Its regular use might limit the need for surgery in this type of tumor. Further studies with large number of patients are highly recommended.