Is 18 F fluorodeoxyglucose PET useful in the management of thyroid cancer?
In general, FDG PET has no application in the initial diagnosis of thyroid cancer because there is overlap of FDG uptake between benign and malignant thyroid tumors. FDG PET can be very useful, however, in patients previously treated for thyroid cancer who now have increasing tumor markers and an 131 I scan with negative results. FDG PET can be a useful adjunct imaging modality to help detect sites of tumor recurrence ( Figure 80-8 ). The sensitivity for detection of tumor recurrence with FDG PET is improved with hormonal withdrawal or administration of recombinant TSH. FDG PET also has a role in the management of patients with anaplastic, Hürthle cell, or medullary thyroid cancers because these tumors are not iodine avid.