Amino Acid Transport Imaging of Parathyroid Adenomas With Anti-3-[18F]FACBC

Hyperparathyroidism (excessive production of parathyroid hormone (PTH) usually caused by a small growth called an adenoma in the parathyroid glands) is an increasingly significant medical and public health condition.

Surgery is the only effective management for primary hyperparathyroidism. However; it is sometimes difficult to pinpoint the adenoma, in part because current methods of imaging often fail to identify the parathyroid adenoma in as many as 30% of patients. In reoperative parathyroidectomy for persistent or recurrent hyperparathyroidism, localization plays an even greater role. Unfortunately current multiple imaging methods fail to localize 10-15% these of tumors.

SPECT/CT with the radiotracer 99mTc sestamibi has become the standard method for pinpointing the tumor. This, however, is a challenge because the parathyroid glands usually are located close to the thyroid and the radiotracer 99mTc sestamibi concentrates both in thyroid and parathyroid tissue. Hence there is a need for a tracer/imaging tool that concentrates in the parathyroid but not in the thyroid.

A more sensitive and specific radiotracer/tracking agent would markedly improve the investigators ability to identify parathyroid tumors preoperatively, and thus offer more patients a minimally invasive parathyroidectomy.

anti-3-[18F]FACBC is an amino acid based PET radiotracer which has shown utility in detecting a variety of tumors. In cell culture experiments, anti-3-[18F]FACBC has shown uptake in parathyroid cells greater than thyroid cells. Therefore, the investigators think that this radiotracer may be able to help us identify parathyroid adenomas better than 99mTc sestamibi.

The primary aim of this study is to determine if anti-3-[18F]FACBC PET-CT demonstrates uptake within parathyroid adenomas. 12 patients with a diagnosis of primary hyperparathyroidism will undergo PET-CT using anti-3-[18F]FACBC in addition to the standard 99mTc sestamibi scanning and other imaging as clinically appropriate such as ultrasound, MRI, and/or contrast enhanced CT scanning. Since all these patients undergo surgery routinely, the investigators will then compare findings at surgery to those of the anti-3-[18F]FACBC PET-CT to determine if this radiotracer is worthy of further study in a more comprehensive experiment.