Diagnostic performance of ultrasound vs. ultrasound-guided FNAc in thyroid nodules: data from the ElaTION trial

ElaTION is a large multi-centre pragmatic randomised controlled trial, performed in 18 secondary/tertiary hospitals across England, comparing elastography ultrasound-guided fine needle aspiration cytology (EUS-FNAC) with ultrasound-guided FNAC (US-FNAC) alone in the diagnostic assessment of thyroid nodules. Secondary trial outcomes, reported here, assessed the accuracy of ultrasound-alone (US) compared with US-guided FNAC to inform and update current practice guidelines. Adults with single or multiple thyroid nodules who had not undergone previous FNAC were eligible. Radiologists assessed all thyroid nodules using US alone, thereby enabling assessment of its accuracy (sensitivity and specificity) versus US-FNAC. Of the 982 participants, a final definitive diagnosis was obtained in 688, who were included in the final analyses. The sensitivity of US-alone was the same as US-FNAC (0.91, [95% CI 0.85, 0.97] vs 0.87 [95%CI 0.80-0.95], p=0.37). US alone had statistically significant lower specificity than US-FNAC alone (0.48 vs 0.67 respectively, p