The diagnostic value of 124I-PET in patients with differentiated thyroid cancer.
BACKGROUND
The purpose of this prospective study was to evaluate the clinical diagnostic value of iodine-124 (124I)-positron emission tomography (PET) in patients with advanced differentiated thyroid carcinoma (DTC) and to compare the 124I-PET imaging results with the 131I whole-body scan (WBS).


METHODS
Twenty patients with histologically proven advanced DTC (including T4, extra-nodal tumour growth, or distant metastases) underwent diagnostic 131I-WBS, 124I-PET scan, and post-treatment 131I-WBS 4 months after ablation. The findings on the 124I-PET were compared with the findings on the diagnostic and post-therapeutic 131I-WBS and were also correlated with radiologic and/or cytological investigations.


RESULTS
124 I-PET vs diagnostic 131 I-WBS. Eleven patients showed uptake on the 124I-PET. Only 3 of these 11 patients also showed uptake on the diagnostic 131I scan, but the uptake was more clearly visible and the abnormalities were more extensive on the 124I-PET. 124 I-PET vs post-treatment 131 I-WBS. Eleven patients showed uptake on the 124I-PET, which was also visible on the post-treatment scan in nine patients; in the other two patients, no uptake was observed on the post-treatment scan and no anatomical localisation could be confirmed. Two patients showed only uptake on the post-treatment scan without uptake on the 124I-PET: in one, the uptake was confirmed by MRI, and in the other, no anatomical localisation was found. In seven patients, no uptake was observed on both the scans.


CONCLUSIONS
124I-PET proved to be a superior diagnostic tool as compared to low-dose diagnostic 131I scans and adequately predicted findings on subsequent high-dose post-treatment 131I scans.
Phan
Ha T T
HT
Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Jager
Pieter L
PL
Paans
Anne M J
AM
Plukker
John T M
JT
Sturkenboom
M G G
MG
Sluiter
W J
WJ
Wolffenbuttel
Bruce H R
BH
Dierckx
Rudi A J O
RA
Links
Thera P
TP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging*
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals