This study was conducted to determine the feasibility of detecting BRAF(V600E) circulating tumor DNA (ctDNA) in the plasma of patients with thyroid nodules, with the goal of distinguishing between benign and malignant nodules. Plasma samples from patients undergoing thyroid surgery for thyroid nodules were obtained prospectively pre-operatively and one month post-operatively, and quantitative-PCR was used determine the presence of BRAF(V600E) ctDNA. These were compared to formalin fixed paraffin embedded samples from the index nodule. Thirty-eight pairs of preoperative and postoperative plasma samples were collected and analyzed. 6/18 (33.3%) patients with classical PTC and 0/8 (0%) patients with nodular hyperplasia had detectable levels of BRAF(V600E) ctDNA pre-operatively, thus BRAF(V600E) ctDNA was able to distinguish between benign and malignant nodules (p \u3c 0.05). The levels of all samples with detectable BRAF(V600E) ctDNA pre-operatively declined post-operatively (p \u3c 0.05). BRAF(V600E) ctDNA can be detected in plasma. Post-operative drop of BRAF(V600E) ctDNA in all cases suggests its utility as a tumor marker
