Value of surveillance ultrasound following hemithyroidectomy.

Background: There is limited evidence or agreement on the benefit, duration and frequency of post-operative surveillance neck ultrasound in patients with differentiated thyroid cancer treated with hemithyroidectomy alone. This study's primary aim was to assess the benefit of neck ultrasound in this situation, with a secondary aim to assess the detection of malignancy in the contralateral lobe in patients undergoing completion surgery.

Methods: A retrospective observational study was conducted involving patients who had differentiated thyroid cancer found at diagnostic hemithyroidectomy between 1 December 2013 and 31 December 2016.

Results: Of 105 patients, 74 underwent completion thyroidectomy. Thirty-five per cent of these patients had malignancy identified in the contralateral lobe, the majority were unsuspected sonographically. Of 31 hemithyroidectomy patients, 1 had a nodule classified as 'U3' (indeterminate) at the first ultrasound surveillance, ultimately identified as incidental papillary microcarcinomas on completion thyroidectomy. There was no other disease recurrence or malignancy at a median of 3.8 years' follow up.

Conclusion: The findings indicate a limited role for ultrasound follow up of patients with differentiated thyroid cancer treated with hemithyroidectomy alone.