**Core Concept**
A Sestamibi scan is a type of nuclear medicine imaging test that utilizes Technetium-99m (Tc-99m) pertechnetate labeled with MIBI (a cationic complex). It is primarily used for detecting and localizing parathyroid adenomas or hyperplasia, and also for breast cancer imaging. The scan relies on the differential uptake of the radiotracer by various tissues, allowing for the visualization of specific areas of interest.

**Why the Correct Answer is Right**
The Sestamibi scan works by exploiting the unique properties of the Tc-99m MIBI complex. This radiotracer is selectively taken up by mitochondria-rich cells, such as those found in parathyroid tissue and some breast cancer cells. The scan is particularly useful in identifying parathyroid adenomas, which have increased mitochondrial density. The imaging process involves the intravenous administration of the radiotracer, followed by a series of gamma camera images that capture the distribution and concentration of the Tc-99m MIBI complex in the body. This allows for the localization of parathyroid adenomas or hyperplasia, and also for breast cancer staging and detection.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Sestamibi scan is not primarily used for detecting thyroid nodules or thyroid cancer. While it can provide some information on thyroid function, its primary application is in parathyroid and breast imaging.
**Option B:** This option is incorrect because Sestamibi scan is not a primary diagnostic tool for lung cancer. Although it can be used in some cases, its utility is limited in this context.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Sestamibi scan results should always be interpreted in conjunction with clinical and laboratory findings. A positive Sestamibi scan can indicate the presence of a parathyroid adenoma or hyperplasia, but further diagnostic workup, including fine-needle aspiration or surgical exploration, may be necessary to confirm the diagnosis.

**Correct Answer:** D. Breast cancer and parathyroid adenoma localization.