Imaging Recommendations for Diagnosis, Staging, and Management of Cancer of the Thyroid, Parathyroid, and Salivary Glands

Abstract

Thyroid cancer ranks as the leading endocrine malignancy in adults. The foundation for primary diagnosis of thyroid cancer is a high-resolution ultrasound (US) of the thyroid gland including US-guided fine-needle biopsy (FNB) of suspected thyroid nodules. Advanced cross-sectional imaging, including computed tomography (CT), magnetic resonance imaging, and positron emission tomography, can be useful in selected patients. The mainstay of treatment of thyroid cancer is surgery. It may be supplemented by radioactive iodine ablation/therapy in high-risk differentiated thyroid cancer. Radiology plays a crucial role in both diagnostic and posttreatment follow-up imaging. Primary hyperparathyroidism (PHPT) is the third most common endocrine disorder with single parathyroid adenoma being its most common cause. The radiologist's aim in parathyroid imaging is to provide the clinician with an illustrative picture of the neck, locating lesions with respect to landmarks. Imaging helps in the detection of solitary versus multiglandular disease, ectopic and supernumerary glands with precise localization. US, nuclear imaging, and four-dimensional CT are the most commonly used imaging modalities for the preoperative localization of the parathyroid disease. Salivary gland tumors account for approximately 0.5% of all neoplasms, the most common location being the parotid gland (70%). Imaging is crucial in salivary gland tumors by defining its location, detecting malignant features, assessing local extension and invasion, staging the tumors according to the tumor-node-metastasis classification, and assessing the feasibility of surgery.