Postoperative assessment after thyroid cancer surgery

Postoperative assessment after thyroid cancer surgery is performed in the surgical bed and regional lymph nodes, looking for possible recurrence of disease.

Radiographic features

Ultrasound

• usually performed in first 6-12 months, and then as needed by the patient's risk factors
• suspicious lymph nodes are biopsied with fine needle aspiration (FNA)
  • thyroid cells in the node indicate a metastasis
  • if the FNA is nondiagnostic, an assay for elevated thyroglobulin in the sample will indicate a metastasis
• ~34% of postoperative patients have small thyroid bed nodules
  • rate of growth is slow and 81% do not increase in size over a three-year period
  • only 33% of malignant nodules show interval growth

Nuclear medicine

content pending

CT

Ultrasound is the first line modality for evaluation of the postoperative neck.

CT may be useful in certain situations :

• bulky and widely distributed recurrent nodal disease, where ultrasound may not completely delineate disease

• assessment of possible invasive recurrent disease where potential aerodigestive tract invasion requires complete assessment

• when neck ultrasound is felt to be inadequately visualizing possible neck nodal disease (e.g. high thyroglobulin, negative neck US)

When CT is employed in followup, this is often performed without contrast in the early post-operative period if radio-iodine ablation has not been performed, since iodinated contrast can compete with radio-iodine treatment for uptake. If a study with IV contrast is necessary, radioiodine can be administered 4–8 weeks following the injection of contrast medium .

Differential diagnosis

• scar fibrosis: often more linear in shape
• suture granuloma
• postoperative / traumatic neuroma
• residual thyroid tissue

Siehe auch:

• Heiserkeit