Comparison of delayed enhanced CT and 18F-FDG PET/CT in the evaluation of adrenal masses in oncology patients.

Objective: To retrospectively compare delayed enhanced computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET)/CT (PET/CT) evaluating adrenal masses in oncology patients undergoing both examinations.

Methods: Twenty adrenal masses in 14 patients were retrospectively included. For delayed enhanced CT, a metastasis was diagnosed if a mass had an absolute percentage loss of enhancement value of less than 60%. For PET/CT, a metastasis was diagnosed if a mass had FDG uptake equal to or greater than that of the liver.

Results: The adrenal masses were confirmed as 8 metastases and 12 adenomas by pathological examinations in 5 patients and follow-up CT examinations in 9 patients. The sensitivity and specificity for adenoma at delayed enhanced CT were all 100% and were 88 (7/8) and 75% (9/12) for PET/CT, respectively. Delayed enhanced CT correctly characterized 1 more metastasis and 3 more adenomas than PET/CT.

Conclusions: Delayed enhanced CT might characterize adrenal masses in oncology patients more exactly than PET/CT.