Fluorodeoxyglucose-positron-emission tomography/computed tomography imaging for adrenal masses in patients with lung cancer: review and diagnostic algorithm.
OBJECTIVE
Positron-emission tomography/computed tomography (PET/CT) with fluorine-18 fluorodeoxyglucose (FDG) is used as first-line staging for patients with newly diagnosed non-small cell lung cancer (NSCLC). Our purpose was to review the accuracy of FDG-PET/CT to predict adrenal gland metastasis, explain the causes for false-positive PET, and provide a diagnostic algorithm.


METHODS
Two patients with incidentally discovered lung masses were found to have hypermetabolic adrenal activity by FDG-PET/CT with maximal standard uptake value (SUV) of 4.5 and 6.5. A MEDLINE search was performed on the topic of FDG-PET/CT, adrenal gland metastasis, and NSCLC. Literature was reviewed with regard to diagnosis, accuracy, outcomes, and alternative imaging or diagnostic strategies.


RESULTS
Both patients underwent transabdominal laparoscopic adrenalectomy and were found to have nodular hyperplasia without evidence of adrenal tumor. A total of seven articles containing 343 patients were identified as having pertinent oncologic information for NSCLC patients with adrenal lesions. Sensitivity and specificity of PET/CT for distant metastasis was 94% and 85%, respectively, but only 13% (44/343) of these patients had histologically confirmed adrenal diagnoses. Based on this, a diagnostic algorithm was created to aid in decision making.


CONCLUSIONS
Although PET/CT has high sensitivity and specificity for adrenal metastasis in the setting of NSCLC, adrenal biopsy or other secondary imaging should be considered to confirm the finding. Adrenalectomy in lieu of biopsy may have both diagnostic and therapeutic benefit in cases where the adrenal mass is ≥10 mm with high PET maximum SUV (≥3.1) and SUV ratios (>2.5), where washout CT or chemical shift MRI is positive, or where percutaneous biopsy is deemed too difficult or unsafe.
1 Department of Urology, University of Florida , Gainesville, Florida.
W Zachary
WZ
Stone
David C
DC
Wymer
Benjamin K
BK
Canales
D000310:Adrenal Gland Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary; D000465:Algorithms; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology; D019788:Fluorodeoxyglucose F18; D006801:Humans; D033162:Incidental Findings; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18