The added benefit of a dedicated neck F-18 FDG PET-CT imaging protocol in patients with suspected recurrent differentiated thyroid carcinoma.
OBJECTIVE
To retrospectively analyze whether adding a delayed high-resolution dedicated neck F-18 FDG positron emission tomography-computerized tomographic (PET-CT) imaging protocol in patients with recurrent differentiated thyroid cancer increases the number of abnormal foci within the neck.


METHODS
Seventeen PET-CT studies from a total of 10 patients with suspected recurrent differentiated thyroid cancer between March 2003 and June 2004 were retrospectively reviewed. Each study included a whole body acquisition (WBA), followed by higher resolution dedicated neck acquisition (DNA). Two board-certified nuclear medicine physicians reviewed either the DNA or WBA for each study and recorded the number of abnormal foci, along with presence or absence of a soft tissue abnormality, and maximum standardized uptake value for each foci. Consensus review was used for all discrepancies. Statistical analysis was performed to determine whether there was a statistically significant increase in the number of studies demonstrating new abnormal foci with the addition of a DNA.


RESULTS
Five of 17 studies demonstrated an increase in the number of abnormal foci with the addition of the DNA (P < 0.04). A total of 8 abnormal foci were noted on the WBA, 4 of which were within the neck. Eleven additional abnormal foci were seen on the DNA. All abnormal foci within the neck had corresponding soft tissue abnormalities except for one.


CONCLUSIONS
Adding a higher resolution delayed DNA to the WBA for patients undergoing PET-CT imaging to detect recurrent thyroid cancer increases the number of abnormal sites of FDG accumulation.
Davison
Jonathan M
JM
Department of Radiology, Walter Reed Army Medical Center, Nuclear Medicine Clinic, Washington, DC 20307, USA. jonathan.davison@gmail.com
Stocker
Derek J
DJ
Montilla-Soler
Jaime L
JL
Jurgens
Jennifer S
JS
Allen
Thomas W
TW
Holley
Timothy S
TS
Stack
Aaron L
AL
D002277:Carcinoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D002454:Cell Differentiation; D003287:Contrast Media / Q000494:pharmacology; D004247:DNA / Q000737:chemistry; D019788:Fluorodeoxyglucose F18 / Q000494:pharmacology*; D006801:Humans; D009333:Neck / Q000000981:diagnostic imaging / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000494:pharmacology*; D012008:Recurrence; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D004247:DNA