Ultrasound feature | Clinical implication: active surveillance | Clinical implication: surgery |
---|---|---|
Nodule size | As per study inclusion criteria (< 2 cm in Clinicaltrials.gov: NCT03271892) | |
Nodule measurement | Maximum dimension on an axial image, maximum dimension perpendicular to the axial measurement on the same image and the maximum longitudinal dimension on a sagittal image | |
Nodule location | Ensure that PTC is identified and labeled accurately for follow-up, especially in patients with MNG and multiple similar sized nodules | |
Evaluation for extrathyroidal extension (ETE) | Confined to the thyroid parenchyma | Loss of perithyroid echogenic line at site of contact of PTC |
Thyroid margin bulge without disruption of perithyroid echogenic line | ||
Nodule relationship to the trachea | < 7 mm nodule irrespective of relationship to trachea | – |
≥ 7 mm nodule if acute angle to the trachea | ≥ 7 mm if obtuse angle to the trachea | |
Nodule relationship to tracheo-esophageal groove (TEG) | < 7 mm nodule irrespective of relationship to TEG | – |
≥ 7 mm nodule if thyroid rim present between the PTC and TEG | Lacking normal thyroid rim between TEG and PTC or protrusion of nodule to TEG or posteriorly | |
Evaluation of lymph nodes | No suspicious cervical lymph nodes | Lymph node(s) suspicious for metastatic disease (require biopsy confirmation) |
Nodule growth at follow-up | < 3 mm in any one plane | ≥ 3 mm in any one plane or maximal diameter |
(> 3 mm in Clinicaltrials.gov: NCT03271892) |