For which condition is Tc sestamibi particularly useful in localization?

• A. Parathyroid adenoma
• B. Thyroid cancer
• C. Cardiac ischemia
• D. Liver disease

Answer: (A)

Tc sestamibi is particularly useful for localization of parathyroid adenomas. This radiopharmaceutical has an affinity for the parathyroid glands and allows for imaging that can effectively identify abnormal parathyroid tissue. Parathyroid adenomas are often associated with primary hyperparathyroidism, and using Tc sestamibi imaging aids in the preoperative localization of these adenomas, helping to guide surgical intervention.

In the context of the other conditions listed, while Tc sestamibi does have applications in different areas—such as cardiac imaging to assess myocardial perfusion and ischemia—it is not as specialized for these uses as it is for parathyroid visualization. In thyroid cancer, other imaging agents like iodine-123 or iodine-131 are typically preferred due to their effectiveness in thyroid scans. Additionally, liver disease encompasses a variety of conditions where other imaging modalities, like ultrasound or CT, may provide better insight than a sestamibi scan. Thus, its primary utility remains in the detection and localization of parathyroid adenomas.