SRU guidelines for assessment of thyroid nodules

The Society of Radiologists in Ultrasound (SRU) guidelines for the assessment of thyroid nodules were defined in a consensus conference statement published in 2005 focused on which thyroid nodules detected on ultrasonography should undergo fine needle aspiration.

Recommendations

The recommendations apply to thyroid nodules ≥1 cm in maximal diameter, evaluated by ultrasonography, in adult patients without a history of thyroid cancer . The language of the recommendations leave room for physician discretion based on the individual patient scenario. The biopsy technique of choice is ultrasound-guided fine needle aspiration.

Solitary nodule

The risk of malignancy, and therefore management recommendation, depends on the presence of the following sonographic features and size thresholds:

• microcalcifications: strongly consider biopsy if ≥1 cm
• coarse calcifications: strongly consider biopsy if ≥1.5 cm
• solid or mainly solid: strongly consider biopsy if ≥1.5 cm
• mixed solid and cystic or mainly cystic with solid mural component: consider biopsy if ≥2.0 cm
• substantial growth since prior ultrasound: consider biopsy
• almost entirely cystic with none of the above features: biopsy probably unnecessary

Multiple nodules

• multiple nodules: consider biopsy of one or more nodules prioritized by the criteria for solitary nodules in the order listed above
• diffusely enlarged gland with multiple similar-appearing nodules without intervening parenchyma: biopsy is likely unnecessary

Lymphadenopathy

• presence of abnormal lymph nodes: biopsy lymph node and/or ipsilateral nodule (this finding overrides thyroid nodule features)

Nondiagnostic biopsy

If the initial fine needle aspiration is nondiagnostic, a repeat fine needle aspiration should be considered for nodules meeting the original criteria above.