Imaging Post-Thyroidectomy
Whole-body RAI scintigraphy with 123I is recommended within 12 weeks following surgery for postoperative staging in ATA Intermediate and High-Risk patients to detect residual locoregional disease and distant metastasis 37 in order to identify patients who may benefit from additional surgery or RAI for remnant ablation or therapy.39 (GRADE A; SOR 1.07, very strong recommendation) 123I is preferred due to superior imaging resolution, the ability to utilize single photon emission computed tomography with integrated conventional CT (SPECT/CT), and slightly lower dose to the patient, however higher cost may be prohibitive. In such cases, 131I remains an acceptable alternative. While planar imaging is generally used for whole-body RAI scintigraphy, the addition of targeted SPECT/CT when focal abnormal uptake is identified offers improved disease localization and characterization.9 Therefore, when focal RAI uptake is identified on planar imaging, SPECT/CT is recommended. (GRADE C; SOR 2.36, moderate recommendation).