Imaging Off Therapy/Surveillance
Six months postoperatively, all patients without evidence of active disease should undergo surveillance imaging with neck ultrasound, including the surgical bed, central and lateral neck, and upper mediastinum. 9 (GRADE C; SOR 2.0, moderate recommendation) For patients in the ATA pediatric low risk level, ultrasound surveillance should be performed annually for 5 years. In both the ATA pediatric Intermediate and High-Risk groups, ultrasound surveillance should be performed every 6-12 months for 5 years. Neck ultrasound can continue less frequently after 5 years for the intermediate and high-risk levels based on individual recurrence risk.9 Thyroglobulin levels can be useful to guide imaging assessment as a marker of residual or recurrent disease and are performed at similar time points.
123I-diagnostic whole-body scan is recommended in patients treated with RAI at 1-2 years following therapy. (GRADE C; SOR 1.36, very strong recommendation)123I-diagnostic whole-body scan is also recommended in patients with increasing thyroglobulin levels or with concern for recurrence at other imaging. 9 (GRADE A; SOR 1.07, very strong recommendation) Table 3 details timing of imaging surveillance.
Are there late effects that change the goal of surveillance imaging?
Differentiated thyroid cancer recurrence has been reported several decades after initial treatment, therefore long-term surveillance is necessary.9 In addition, relative risk of a secondary primary malignancy, most commonly leukemia, is increased in those treated with RAI.39-43