Malignancy Risk Assessment in Patients with Thyroid Nodules Using Classification and Regression Trees

Figure 3

Optimal decision tree for stratifying patients based on their risk for thyroid cancer. Subjects categorized in the gray boxes (high-risk patients) in the first step are reevaluated in the second step using US findings. Syntax: if nodule size ≤2 cm and hypoechogenicity/microcalcification → high risk. If size >2 cm and (age <30 or >60) and hypoechogenicity/microcalcification → high risk. If (2≤ size ≤5) and (30≤ age ≤60) and male sex and hypoechogenicity/microcalcification → high risk. Otherwise → low risk.