Final answer:
The radioactive iodine uptake test using isotopes like I-131 is commonly used for staging papillary thyroid cancer. Additionally, positron emission tomography (PET) scans with 18-fluorodeoxyglucose (18-FDG) are also utilized for assessing cancer metabolism and staging.
Step-by-step explanation:
The test used for staging papillary thyroid cancer involves the use of radioactive iodine, such as I-131. This isotope is particularly effective because thyroid cells, including cancerous ones, naturally concentrate iodine. The radioactive iodine uptake (RAIU) test can image the thyroid and help in staging the cancer, as the most active thyroid cells emit the most radiation due to their higher iodine concentration.
Apart from radioactive iodine imaging, positron emission tomography (PET) scans using 18-fluorodeoxyglucose (18-FDG) can also be employed. The 18-FDG compound is a glucose analog that includes the radioactive isotope fluorine-18, which accumulates in tissues with high metabolic rates, like rapidly multiplying cancer cells, making PET scans useful for studying cancer cell metabolism and staging thyroid cancer.