AACE Vs ATA Thyroid-Nodule-Management Differences

Based on thyroid nodules’ size and characteristics seen on ultrasound scans, AACE classifies them into three malignancy-risk categories: low, intermediate, and high. ATA goes further, classifying the risk categories as: benign, very low, low, intermediate, and high suspicion.

According to Dr Duick, this difference “most likely reflects decision making where, more commonly, the operator-based sonographer and performer of fine-needle aspiration is an endocrinologist/thyroidologist [in the AACE classification] rather than a radiology technologist, radiologist, or other,” in the ATA classification.

The ATA guidelines recommend that nodules > 1 cm in diameter should be biopsied, but smaller nodules, even if they are suspicious for cancer, only should be followed closely, Dr Gharib said. In contrast, the AACE guideline is somewhat less restrictive and states, “Fine-needle aspiration should be considered for nodules < 10 mm (1 cm) diameter only when suspicious ultrasound signs are present, while nodules < 5 mm should be monitored rather than biopsied.”

“Importantly, [both guidelines] highlight pattern recognition,” Dr Lupo observed, adding that it is important “to have access to a video clip or do [the ultrasound] yourself, to be able to better distinguish a high-risk feature from an artifact.”

And tests for molecular markers for thyroid cancer, a hotly debated area, are treated differently in the two guidelines, Dr Gharib noted. The ATA guidelines suggest that clinicians should order these tests if cytology findings are atypical, whereas the AACE guideline uses more cautious wording: “At present, no single cytochemical or genetic marker can definitely rule out malignancy in indeterminate nodules. Nevertheless, these tools should be considered together with clinical data.”

There is no need to treat most thyroid nodules, and levothyroxine (LT4) suppression is not recommended, according to the AACE guideline update.

The document also discusses noninvasive treatment in more detail. “Percutaneous ethanol injection (PEI) should be the first-line treatment option for relapsing, benign cystic lesions, while [ultrasound]-guided thermal ablation treatments may be considered for solid or mixed symptomatic benign thyroid nodules,” the AACE authors write.
“Minimally invasive procedures are much more commonly done in Europe than in the United States,” Dr Gharib observed, adding that “we have to tell our colleagues” that alcohol ablation is easy to do and radiofrequency ablation is both effective and cost-effective.

Last, “surgery remains the treatment of choice for malignant or suspicious nodules,” according to the AACE thyroid nodule management guideline update.

Need to Consider Individual Patient, Avoid Overtreatment

According to Dr Gharib, technologic advances are enabling clinicians to detect smaller nodules, which often leads to surgery, and “perhaps we are a little bit too aggressive with chasing small nodules.”

In any case, “the individual patient situation may not conform to rigid guidelines,” Dr Lupo noted. “You have to always use clinical judgment and tools that are available in your location.