Notification of abstract acceptance
announced via E-mail on July 31st.
Abstract view



Oct. 19 (Fri)  208 Room - SS24 GU
17:20-17:30 [SS 24 GU-09] 
Comparison of Adrenal Protocol CT and 18FDG-PET/CT: Accuracy for Adenoma Characterization
   
Speaker Sung Yoon Park (Samsung Medical Center)
Authors Sung Yoon Park,Byung Kwan Park,Chan Kyo Kim
Affiliation Samsung Medical Center
PDF View  SS 24 GU-09.pdf

PDF File View :
PURPOSE:
To compare adrenal protocol CT and 18FDG-PET/CT for accuracy for adenoma characterization.

MATERIALS AND METHODS:
This retrospective study was approved byIRB and informed consent was waived. Between June 2006 and December 2010, 75 oncologic patients with 75 solid adrenal masses underwent both adrenal protocol CT and 18FDG-PET/CT. For adrenal protocol CT, adenoma was diagnosed if a mass had an absolute percentage loss of enhancement (PLE) of more than 60% or relative PLE of more than 40%. Absolute and relative PLE values were calculated by [CTE – CTD] x 100/[CTE – CTU] or by [CTE – CTD] x 100/CTE: CTU, CTE, and CTD were attenuation values of an adrenal mass at unenhanced, early, and delayed enhanced CT. For 18FDG-PET/CT, adenoma was diagnosed if a mass was iso- or hypermetabolic compared to liver. Sensitivity, specificity, positive predictive value, and negative predictive value for adenoma were compared between adrenal protocol CT and 18FDG-PET/CT. The sensitivity for adenoma of adrenal protocol CT and 18FDG-PET/CT was obtained with a standard reference of pathologic diagnosis or size stability on follow-up examination. McNemar¡¯s test was used for comparison of adrenal protocol CT and 18FDG-PET/CT in terms of accuracy for adenoma.

RESULTS:
Of 75 adrenal masses, 54 were histologically or clinically confirmed as adenoma. Sensitivity, specificity, positive predictive value, and negative predictive value for adenoma using adrenal protocol CT and 18FDG-PET/CT were 87% (47/54) and 81% (44/54), 90% (19/21) and 81% (17/21), 96% (47/49) and 92% (44/48), and 73% (19/26) and 63% (17/27), respectively. Therefore, overall accuracies for adenoma using adrenal protocol CT and 18FDG-PET/CT were 88% (66/75) and 81% (61/75), respectively However, there was no significant difference between adrenal protocol CT and 18FDG-PET/CT in terms of accuracy for adenoma (p= 1.00).

CONCLUSION:
18FDG-PET/CT may miss a substantial number of adenomas that are correctly diagnosed by adrenal protocol CT although there is no significant difference between these two modalities in terms of accuracy for adenoma.

¨Ï Korean Society of Radiology. All Rights Reserved.