Name of the Procedure:

Common names: Iodine I-131 Capsule, Diagnostic I-131 Scan
Technical term: Iodine I-131 Sodium Iodide Capsule(s), Diagnostic

Summary

This procedure involves taking a capsule that contains a small amount of radioactive iodine (I-131). It's used to help doctors see how well your thyroid gland is functioning by using a special camera to capture images of the iodine in your body.

Purpose

The primary goal of this procedure is to assess thyroid function and detect any abnormalities such as hyperthyroidism, thyroid nodules, or cancer. It helps in diagnosing thyroid conditions and planning further treatment.

Indications

• Symptoms or suspicions of thyroid dysfunction (e.g., swelling of the thyroid gland, unexplained weight changes, fatigue).
• Screening for thyroid cancer or monitoring its treatment.
• A history of thyroid nodules or goiter.

Preparation

• Fast for at least 4-6 hours before taking the capsule.
• Avoid certain foods and medications that might interfere with the results (e.g., shellfish, iodized salt, thyroid medications) for a specified period before the test.
• Inform your doctor if you are pregnant or breastfeeding.

Procedure Description

1. The patient swallows a capsule containing a specified dose of Iodine I-131.
2. The radioactive iodine is absorbed by the thyroid gland over a period of time.
3. Typically after 24 hours, the patient returns for imaging.
4. A special gamma camera is used to take pictures of the thyroid gland, showing how much of the Iodine I-131 has been absorbed.
5. The captured images help in evaluating the thyroid’s function and structure.

No sedation or anesthesia is required for this procedure.

Duration

The initial capsule ingestion takes only a few minutes. The imaging usually happens 24 hours later and takes about 30 minutes.

Setting

• Outpatient clinic
• Radiology department in a hospital

Personnel

• Nuclear medicine technologist
• Radiologist
• Endocrinologist (sometimes involved in interpretation)

Risks and Complications

• Mild radiation exposure, but generally low risk.
• Rare allergic reaction to the iodine.
• Slight possibility of temporary discomfort or swelling in the thyroid gland.

Benefits

• Provides detailed and accurate information about thyroid function and structure.
• Helps in diagnosing or ruling out thyroid conditions.
• Can guide treatment options for thyroid disorders.

Recovery

• Most patients can resume normal activities immediately after the imaging.
• Instructions may include drinking plenty of fluids to help flush out the radioactive iodine.
• Follow-up appointments may be necessary based on the test results.

Alternatives

• Blood tests for thyroid hormones and antibodies.
• Ultrasound of the thyroid gland.
• Fine-needle aspiration biopsy if a thyroid nodule or suspicious area is found.

Patient Experience

• Ingesting the capsule is easy and painless.
• During the imaging, you will need to lie still, which might cause mild discomfort.
• Post-procedure, you may be advised to avoid close contact with pregnant women and young children for a short period due to the minimal radiation exposure.

Pain management is usually not required, and comfort measures include staying hydrated and following any personalized instructions from your healthcare provider.