Frequent Screening With Serial Neck Ultrasound Is More Likely to Identify False-Positive Abnormalities Than Clinically Significant Disease in the Surveillance of Intermediate Risk Papillary Thyroid Cancer Patients Without Suspicious Findings on Follow-Up Ultrasound Evaluation

Context: American Thyroid Association (ATA) intermediate-risk thyroid cancer patients who achieve an excellent treatment response demonstrate a low risk of structural disease recurrence. Despite this fact, most patients undergo frequent surveillance neck ultrasound (US) during follow-up. Objective: The objective of the study was to evaluate the clinical utility of routine screening neck US in ATA intermediate-risk patients documented to have a nonstimulated thyroglobulin less than 1.0 ng/mL and a neck US without suspicious findings after therapy. Patients and Design: Retrospective review of 90 ATA intermediate-risk papillary thyroid carcinoma patients treated with total thyroidectomy and radioactive iodine ablation in a tertiary referral center. Main Outcome Measures: A comparison between the frequency of finding false-positive US abnormalities and the frequency of identifying structural disease recurrence in the study cohort was measured. Results: Over a median of 10 years, 90 patients had a median of six US (range 2–16). Structural disease recurrence was identified in 10% (9 of 90) at a median of 6.3 years. Recurrence was associated with other clinical indicators of disease in 5 of the 90 patients (5.6%, 5 of 90) and was detected without other signs of recurrence in four patients (4.8%, 4 of 84). False-positive US abnormalities were identified in 57% (51 of 90), leading to additional testing, which failed to identify clinically significant disease. Conclusions: In ATA intermediate-risk patients who have a nonstimulated thyroglobulin less than 1.0 ng/mL and a neck US without suspicious findings after therapy, frequent US screening during follow-up is more likely to identify false-positive abnormalities than clinically significant structural disease recurrence.