SPECT/CT imaging in children with papillary thyroid carcinoma
Pediatric Radiology, 06/07/2011
Kim HY et al. – SPECT/CT precisely localizes neck iodine uptake. In small numbers of patients, treatment is affected. SPECT/CT should be used when available in thyroid carcinoma patients.Methods
- 20 SPECT/CT and planar studies were reviewed in 13 children with papillary thyroid carcinoma after total thyroidectomy.
- Seven studies used I–123 and 13 used I–131, after elevating TSH by T4 deprivation or intramuscular thyrotropin alfa.
- Eight children had one study and five children had two to four studies.
- Studies were performed at initial post–total thyroidectomy evaluation, follow–up and after I–131 treatment doses.
- SPECT/CT was performed with a diagnostic–quality CT unit in 13 studies and a localization–only CT unit in 7.
- Stimulated thyroglobulin was measured (except in 2 cases with anti–thyroglobulin antibodies).
- In 13 studies, neck activity was present but poorly localized on planar imaging; all foci of uptake were precisely localized by SPECT/CT. Two additional foci of neck uptake were found on SPECT/CT.
- SPECT/CT differentiated high neck uptake from facial activity.
- In six studies (four children), neck uptake was identified as benign by SPECT/CT (three thyroglossal duct remnants, one skin contamination, two by precise anatomical CT localization).
- In two children, SPECT/CT supported a decision not to treat with I–131.
- When SPECT/CT was unable to identify focal uptake as benign, stimulated thyroglobulin measurements were valuable.
- In three of 13 studies with neck uptake, SPECT/CT provided no useful additional information.