SPECT/CT imaging in children with papillary thyroid carcinoma

Department of Radiology, Cincinnati Children's Hospital, Cincinnati, OH 45229, USA.
Pediatric Radiology (Impact Factor: 1.57). 05/2011; 41(8):1008-12. DOI: 10.1007/s00247-011-2039-x
Source: PubMed


SPECT/CT improves localization of single photon-emitting radiopharmaceuticals.
To determine the utility of SPECT/CT in children with papillary thyroid carcinoma.
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.
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.

10 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: One of the main problems in quantification of single photon emission computer tomography imaging is scatter. In iodine-123 (I-123) imaging, both the primary 159 keV photons and photons of higher energies are scattered. In this experimental study, different scatter correction methods, based on energy window subtraction, have been compared with each other. Iodine-123 single photon emission computed tomography images of a phantom with a known intensity ratio between background and hollow spheres were acquired for three different collimators (low energy high resolution, low energy general purpose, and medium energy general purpose). The hollow spheres were filled with a higher activity concentration than the uniform background activity concentration, resulting in hot spots. Counts were collected in different energy windows, and scatter correction was performed by applying different methods such as effective scatter source estimation, triple and dual energy window (TEW and DEW), double peak window (DPW) and downscatter correction. The intensity ratio between the spheres and the background was used to compare the performance of the different methods. The results revealed that the efficiency of the scatter correction techniques vary depending on the collimator used. For the low energy high resolution collimator, all correction methods except the effective scatter source estimation and the DPW perform well. For the medium energy general purpose collimator, even without scatter correction, the calculated ratio is close to the real ratio. The DEW and DPW methods tend to overestimate the ratio. For the low energy general purpose collimator, only the DEW and the combined DEW and downscatter correction methods perform well. The only correction method that provides a ratio that differs by less than 5% from the real ratio for all the collimators is the combined DEW and downscatter correction method.
    No preview · Article · Apr 2012 · Nuclear Medicine Communications
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Radioiodine scintigraphy and therapy has played a major role in the treatment and follow-up of thyroid cancer patients for decades. Single-photon emission computed tomography/computed tomography in this setting is emerging as a useful tool in accurately localizing sites of pathological uptake and physiological mimics of disease, thus providing more accurate staging prognostic information for risk stratification, which in turn tailors management and follow-up regimes. This review presents the current evidence and potential indications of single-photon emission computed tomography/computed tomography in thyroid cancer.
    Full-text · Article · Jun 2012 · Nuclear Medicine Communications
  • [Show abstract] [Hide abstract]
    ABSTRACT: Thyroid cancer is the most common endocrine malignancy in adults, with 44,670 (10,740M:33,930F) newly diagnosed cases reported in the USA in 2010 and 1,690 deaths. The incidence of thyroid cancer continues to rise, with a 2.4-fold increase in incidence since 1975, based largely upon detection of small (≤2 cm) tumors, which represent 87 % of newly diagnosed cases. After initial diagnosis, staging and risk stratification are used to individualize treatment decisions, inform on prognosis for an individual patient, decide on the use of postoperative 131I therapy, and determine the frequency and intensity of follow-up. A growing number of studies confirm that radioiodine 131I SPECT/CT is a powerful diagnostic tool, overcoming many limitations encountered with planar imaging interpretation. SPECT/CT reduces the number of equivocal radioiodine foci encountered in the neck and body and allows more precise characterization of the etiology (benign vs. malignant) of focal radioiodine uptake, contributing to completion of staging in thyroid cancer by improved characterization of N and M scores. The additional information obtained with SPECT/CT impacts management in a significant number of patients. The new technology of SPECT/CT has changed the field and may lead to reassessment of current management protocols and guidelines in thyroid cancer. © 2014 Springer-Verlag Berlin Heidelberg. All rights are reserved.
    No preview · Article · Jan 2014
Show more