The American Thyroid Association guidelines are well-researched, easy to follow guidelines for the management of common thyroid problems.
Click on this link to download the relevant set of guidelines which can answer your clinical question:
Although this question should be individualized, the TIRADS classification is a very useful way of determining which nodules to biopsy. TIRADS stands for Thyroid Imaging Reporting and Data System. This is how the radiologists report thyroid nodules based on composition, echogenicity, shape, margin and echogenic foci. Biopsy depends on the nodule’s size and TIRADS classification. This table from UpToDate.com shows this classification and when to biopsy: TI-RADS thyroid nodules
Thyroid technetium scan:
- This is indicated for patients with hyperthyroidism to decide whether this is due to a specific nodule or an overall increased function such as in the case of Graves disease.
- It can also be useful to decide which nodules to biopsy. If a nodule is functioning on a technetium scan, it is unlikely to harbour malignancy. Cold (non-functioning) nodules do not necessarily require a biopsy if their size and appearance on ultrasound do not indicate a biopsy (see above).
- This is indicated if the patient has a thyroid lump or an abnormal technetium scan. The main reason is to assess the gland for the presence of nodules and to assess nodule size and appearance.
- CT scan is indicated if the patient has pressure symptoms or is likely to have retrosternal extension. A non-contrast CT of the neck is advisable to avoid iodine-induced-hyperthyroidism.