Sestamibi Parathyroid Scan is a specialized nuclear medicine test that is used to detect hyperfunctioning (overactive) parathyroid glands in patients with hyperparathyroidism.

It is a non-invasive scan that is crucial in pre-operative localization of parathyroid adenoma or hyperplasia, so that it assists surgeons to carry out specified and less invasive surgeries.

Hyperparathyroidism is a situation in which the parathyroid glands develop excess parathyroid hormone (PTH), and this results in a disruption in calcium levels in the body. Localization of the affected gland(s) is crucial to an effective treatment.

The scan involves 99mTc-sestamibi (Tc-99m MIBI), a scintigraphic radiotracer that is internalized selectively by the hyperplastic parathyroid tissue- even when it is utrophic, ectopic, as behind the thyroid or in the chest.

What is a Sestamibi Parathyroid Scan?

This is an imaging examination that assesses the activity of the parathyroid tissue metabolism.

Glands that are hyperfunctional capture and trap the radiotracer longer since they have more mitochondrial functions and are thus depicted in imaging.

Imaging Phases:

• Early Phase (10–15 minutes post-injection):
  Shows initial tracer uptake in both thyroid and parathyroid tissue
• Delayed Phase (90–120 minutes post-injection):
  Normal thyroid tissue washes out the tracer, while abnormal parathyroid glands retain it

The SPECT/CT images are also commonly used to add 3D localization of the images, potentially enhancing both diagnostic assessment and the procedures performed on patients.

Clinical Applications

The scan is extensively used in patients having various forms of hyperparathyroidism:

Key Indications:

• Primary hyperparathyroidism (usually because of a solitary adenoma)
• Multifocal glandular malady or parathyroid hyperplasia.
• Preoperative preparation of minimally invasive parathyroidectomy.
• Recurrence and persistent disease: Reoperative surgery.
• Focalization of extrapyramidal parathyroid tissue.
• Distinction of thyroid nodules.
• Operative decision-making to prevent unwarranted exploration.

How is the Scan Performed?

This procedure is performed in a department of nuclear medicine, and it usually requires a duration of 2-3 hours.

Step-by-step process:

• Small dose injection of Tc-99m sestamibi into a vein.
• A gamma camera for early imaging (10-15 minutes).
• Also delayed imaging (90-120 minutes).
• Obligatory SPECT/CT scan in case of necessary 3D localization.

What Does the Scan Reveal?

The scan identifies hyperactive glands of the parathyroid as repeat persistence hot spots on the delayed images.

It Helps Identify:

• Abnormal glands: Number and position.
• Single adenoma and multigland disease.
• Ectopic parathyroid tissue
• Precise positioning of localized surgery.
• Recurrent or residual postoperative disease.

Benefits of Sestamibi Parathyroid Scan

• Painless and very precise.
• Facilitates the least invasive parathyroid surgery.
• Minimizes the necessity of doing deep neck exploration.
• Enhances the success of surgery.
• Identifies ectopic glands in inaccessible places.
• Supersets with modern SPECT/CT imaging.
• Applicable in complicated or recurrent surgeries.

Limitations

• Potential false positives (i.e., thyroid nodules, lymph nodes)
• Small adenomas could be missed sometimes.
• Weaker in certain multiglandular or secondary instances.
• May demand correlation with either ultrasound or CT.

Preparation for the Scan

• Fasting: Not required
• Continue regular medications unless advised otherwise
• Inform your doctor if pregnant or breastfeeding
• Remove jewelry or metallic objects from the neck area
• Share any history of thyroid or parathyroid surgery

Why Choose Molecular Diagnostics and Therapy?

• State-of-the-art nuclear medicine imaging systems.
• Senior specialists who guarantee accurate diagnosis.
• Good precision with the capability of SPECT/CT features.
• Close attention to the patient and advanced safety measures.
• Fast and reliable reporting

Conclusion

Sestamibi Parathyroid Scan is an imaging method of detecting and localizing hyperfunctioning parathyroid glands that is the gold standard method of imaging. It is important to use it in directing surgeries, which are less reported, enriching the effectiveness of its treatment, and minimizing the risk of surgery.

This scan is important in leading to precise surgical procedures, quick recovery, and effective management of hyperparathyroidism in the long-term due to the ability to give both the functional and localization scans.

Test Information

• Fasting: Not required
• Reporting Time: Within 2–24 hours*