Matthew Joseph Brady MD, Presenter: Nothing to Disclose

John Thomas MBBS, Abstract Co-Author: Nothing to Disclose

Erik K. Paulson MD, Abstract Co-Author: Consultant, Siemens AG Consultant, Koninklijke Philips Electronics NV Consultant, General Electric Company

Terrence Zekon Wong MD, PhD, Abstract Co-Author: Nothing to Disclose

To test the hypothesis that adrenal lesion SUVmax may differentiate between adenomas and malignant lesions in a consecutive series of biopsy proven adrenal lesions.

From January, 2003 to December, 2005, 33 patients (mean age 58 years, 64% male, 36% female) with adrenal lesions who underwent either PET or PET/CT and adrenal biopsy were identified. Indications for scanning were: non-small cell lung CA (23), small cell lung CA (2), breast CA (2), melanoma (2), ampullary CA (1), cervical CA (1), unknown primary (1), adrenal lesion with no primary (1). In patients who underwent PET only, data from a recent CT scan was utilized. The size, mean density, lesion SUVmax, and lesionSUVmax/liverSUVavg ratio were measured for each lesion and compared to histologic diagnosis.

Eight adenomas had the following imaging parameters: 2.2 cm (range 1.0-3.3cm), 22.3 HU (range 2.1-43.2HU), SUVmax 5.1 (range 2.0-10.2), lesionSUVmax/liverSUVavg 1.9 (range 0.6-4.1). Twenty-three metastatic lesions had the following imaging parameters: 3.7 cm (range 1.2-8.8cm), 34.9HU (range 14.9-53.5HU), SUVmax 14.1 (range 2.9-25.8), lesionSUVmax/liverSUVavg 5.4 (range 1.2-9.2). One pheochromocytoma measured 2.3cm, 40.9HU, SUVmax 4.5, lesionSUVmax/liverSUVavg 1.7. One angiomyolipoma measured 1.9cm, 21.0HU, SUVmax 7.6, lesionSUVmax/liverSUVavg 4.0.

Though lesion SUVmax for most adenomas is below the SUVavg of liver, some measure well above the SUVavg of liver. However, only two adenomas had values more than 2.5 times that of liver. A lesionSUVmax/liverSUVavg ratio of >2.5 is a specific test for malignancy.

Occasionally adrenal adenomas can have FDG avidity significantly above that of the liver. However, this value is only rarely greater than 2.5 times the liver.

Brady, M, Thomas, J, Paulson, E, Wong, T, Discriminating FDG-avid Adrenal Adenomas from Primary and Metastatic Adrenal Lesions Using SUV: A Biopsy Proven Case Series.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5007049.html