Which imaging modality is used to stage thyroid cancer?

Which imaging modality is used to stage thyroid cancer?

• A. Ultrasound
• B. SPECT
• C. PET
• D. Scintigraphy

Answer: (C)

Staging looks for how far the cancer has spread, not just the original tumor. PET detects metabolic activity across the whole body, so it can reveal distant metastases that other tests might miss. In thyroid cancer, well-differentiated tumors often take up radioactive iodine, which helps with certain scans, but when the disease becomes iodine-refractory or when there’s suspected metastasis with negative iodine uptake, FDG-PET (often combined with CT) provides a sensitive whole-body view of tumor burden. That broader, metabolic perspective makes PET the best choice for staging in this context. Ultrasound is superb for evaluating the thyroid bed and nearby lymph nodes but doesn’t give a whole-body metastasis picture. Scintigraphy and SPECT use radioactive iodine to image functioning thyroid tissue and remnants, which is useful for detecting iodine-avid disease but can miss non-iodine-avid metastases and thus isn’t as comprehensive for staging in advanced cases.

Staging looks for how far the cancer has spread, not just the original tumor. PET detects metabolic activity across the whole body, so it can reveal distant metastases that other tests might miss. In thyroid cancer, well-differentiated tumors often take up radioactive iodine, which helps with certain scans, but when the disease becomes iodine-refractory or when there’s suspected metastasis with negative iodine uptake, FDG-PET (often combined with CT) provides a sensitive whole-body view of tumor burden. That broader, metabolic perspective makes PET the best choice for staging in this context.

Ultrasound is superb for evaluating the thyroid bed and nearby lymph nodes but doesn’t give a whole-body metastasis picture. Scintigraphy and SPECT use radioactive iodine to image functioning thyroid tissue and remnants, which is useful for detecting iodine-avid disease but can miss non-iodine-avid metastases and thus isn’t as comprehensive for staging in advanced cases.