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).