The value of adding (18)F-FDG PET/CT to adrenal protocol CT for characterizing adrenal metastasis (≥ 10 mm) in oncologic patients.
OBJECTIVE
The objective of our study was to evaluate the value that PET/CT adds to adrenal protocol CT for characterizing adrenal metastasis in oncologic patients.


METHODS
Sixty-eight oncologic patients with 68 adrenal masses underwent both adrenal protocol CT and (18)F-FDG PET/CT. For adrenal protocol CT, metastasis was diagnosed if a mass measured more than 10 HU on unenhanced CT and if the absolute and relative percentage washouts were less than 60% and 40%, respectively. For PET/CT, metastasis was diagnosed if FDG uptake of the lesion was equal to or greater than that of the liver. Diagnostic accuracies were compared between these two imaging modalities.


RESULTS
The accuracy of adrenal protocol CT and PET/CT for a metastatic lesion, defined as a lesion with FDG uptake equal to or higher than that of the liver, was 85.3% (58/68) and 76.5% (52/68), respectively. However, the accuracy of PET/CT increased to 89.7% (61/68) when a lesion with high FDG uptake alone was considered a metastatic lesion. When both adrenal protocol CT and PET/CT were positive for metastasis, the accuracy increased to 91.2% (62/68), but the sensitivity decreased to 70.6% (12/17).


CONCLUSIONS
Adding PET/CT to adrenal protocol CT improves the accuracy for adrenal metastasis in oncologic patients when a lesion with high FDG uptake alone is considered metastasis.
1 All authors: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, Korea.
Sung Yoon
SY
Park
Byung Kwan
BK
Park
Chan Kyo
CK
Kim
D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D007472:Iohexol; C038192:iopromide