01-01-2016 | Endocrine cancers | Book chapter | Article
15. Imaging for Preoperative Assessment and Staging of Thyroid Cancer
Authors: James X. Wu, M.D., Michael W. Yeh, M.D., F.A.C.S.
Publisher: Springer International Publishing
Abstract
Long-term outcomes in thyroid cancer are heavily influenced by the quality of surgery, which is in turn dependent on thorough preoperative imaging. Neck ultrasound is the first-line imaging modality in the planning of both initial and subsequent surgery for thyroid cancer. Ultrasound is useful in characterizing both the primary tumor and suspicious cervical lymph nodes. Lymph nodes classified as abnormal based on size, shape, internal sonographic features, and blood flow patterns may be investigated further with fine-needle aspiration biopsy (FNA) and/or targeted for compartmental clearance. In the vast majority of thyroid cancer cases, ultrasound alone is sufficient for surgical planning.
In select patients, cross-sectional imaging with CT or MRI may supplement ultrasound. Indications for cross-sectional imaging include clinical or sonographic evidence of local invasion or the finding of extensive disease (either the primary tumor or malignant lymphadenopathy) that extends beyond the area that can be fully imaged by ultrasound. Cross-sectional imaging may also be indicated when ultrasound expertise is not available at a given institution, though this scenario is likely diminishing in frequency given the recent expansion of formal ultrasound training across several clinical disciplines. At present, the role of functional imaging with PET-CT is limited to a subset of patients with disease recurrence.