## **Core Concept**
The management of residual disease after surgery for papillary thyroid carcinoma (PTC) involves assessing the extent of disease and planning further treatment. A whole-body iodine scan (WBIS) is a critical tool for detecting iodine-avid metastatic or residual thyroid tissue. The presence of residual disease on WBIS 6 weeks post-surgery indicates the need for further intervention.

## **Why the Correct Answer is Right**
The correct approach for managing residual disease detected by WBIS involves radioactive iodine ablation (RAIA) to destroy any remaining thyroid tissue and microscopic disease. This step is crucial because it facilitates the use of thyroglobulin (Tg) as a tumor marker for follow-up and improves the sensitivity of WBIS for detecting metastases. Administering radioactive iodine (Option ) is the standard next step for ablation of residual thyroid tissue and for treatment of iodine-avid metastases.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is blank and cannot be evaluated.
- **Option D:** This option is blank and cannot be evaluated.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the timing of radioactive iodine ablation can vary based on several factors, including the extent of disease and the patient's overall health. However, performing RAIA after detecting residual disease on WBIS is a standard approach. Additionally, measuring thyroglobulin levels after ablation and during follow-up is essential for monitoring disease recurrence.

## **Correct Answer:** .