Objective: Reoperation in patients with recurrent hyperparathyroidism usually requires localisation of abnormal glands. Current imaging techniques are not always successful in this group of patients. An evaluation of [11C]methionine positron emission tomography (PET) has been made to assess the ability of the technique to localise abnormal glands in patients with hyperparathyroidism after previous surgery.
Subjects and methods: Eight patients (five with primary, and three with tertiary hyperparathyroidism) who had undergone one to three previous surgical explorations were studied. [11C]methionine PET scans of the neck and mediastinum were performed in all patients. All had recent technetium-99m (99mTc)-labelled sestamibi (n = 7) or thallium-201 (201Tl)/99mTc subtraction (n = 1) parathyroid scans available for comparison. Subsequent surgical correlation was available in all cases.
Results: [11C]methionine PET correctly located an abnormal site of uptake in all five patients with primary hyperparathyroidism compared with only one when conventional nuclear medicine methods were used. In the patients with tertiary hyperparathyroidism, [11C]methionine PET correctly located one, confirmed the absence of cervical or mediastinal abnormality in a patient with an autotransplanted forearm autonomous gland, and failed to demonstrate an abnormality in a third. 99mTc-labelled sestamibi scans were negative in all three patients.
Conclusion: [11C]methionine PET correctly locates abnormal parathyroid glands in the majority of patients with persistent or recurrent hyperparathyroidism after surgery in whom conventional non-invasive nuclear medicine imaging has failed.