Implementation of functional imaging using C-methionine PET-CT co-registered with MRI for advanced surgical planning and decision making in prolactinoma surgery.

PURPOSE

To report the first experience of our multidisciplinary team with functional imaging using C-methionine positron emission tomography-computed tomography (C-methionine PET-CT) co-registered with MRI (Met-PET/MRI) in clinical decision making and surgical planning of patients with difficult to treat prolactinoma.

METHODS

In eighteen patients with prolactinoma, referred to our tertiary referral centre because of intolerance or resistance for dopamine agonists (DA), Met-PET/MRI was used to aid decision-making regarding therapy.

RESULTS

Met-PET/MRI was positive in 94% of the patients. MRI and Met-PET/MRI findings were completely concordant in five patients, partially concordant in nine patients, and non-concordant in four patients. In five patients Met-PET/MRI identified lesion(s) that were retrospectively also visible on MRI. Met-PET/MRI was false negative in one patient, with a cystic adenoma on conventional MRI. Thirteen patients underwent transsphenoidal surgery, with nine achieving full biochemical remission, two clinical improvement and near normalized prolactin levels, and one patient clinical improvement with significant tumour reduction. Hence, nearly all patients (94%) were considered to have a positive outcome. Permanent complication rate was low. Three patients continued DA, two patients have a wait and scan policy.

CONCLUSION

Met-PET/MRI can provide additional information to guide multidisciplinary preoperative and intraoperative decision making in selected cases of prolactinoma. This approach resulted in a high remission rate with a low rate of complications in our expert centre.