Parathyroid imaging and treatment using directed delivery of a noninvasive radiodiagnostic agent.
- Improved identification and localization of parathyroid tumors.
- Increased sensitivity and selectivity in the targeting of parathyroid tissue.
- May be used to deliver therapeutic agents selectively to malignant parathyroid carcinoma cells.
Our technology describes the use of technetium 99-m (99mTc) folate to image parathyroid tissue. 99mTc folate binds to folate receptor positive cells and tissues with high affinity. The current standard of parathyroid therapy is first localizing the parathyroid tumor with 99mTc-sestamibi as a radiotracer followed by parathyroid surgery. However current imaging techniques fail to identify the parathyroid tumor in as many as 30% of patients and current imaging modalities fail to localize 10-15% of tumors. The commonly used radiotracer, 99mTc-sestamibi, binds to both parathyroid and thyroid tissue however we found that 99mTc folate binds to parathyroid but not thyroid tissue. In addition, folate receptors are expressed in parathyroid but not thyroid tissue. Because of these differences between parathyroids and thyroids, 99mTc folate may have a considerable advantage in accurately imaging and localizing parathyroid tumors. With increased sensitivity and accuracy in tumor localization, patients will be able to have focal, minimally invasive parathyroidectomies, improved cure rates, improved cosmesis, and shorter hospital stays.
Proof of principle study shows that 99mTc folate binds to HeLa cells.