Sun Young MD, Presenter: Nothing to Disclose

Jessica C. Lee, Abstract Co-Author: Nothing to Disclose

Robert Corbilla, Abstract Co-Author: Nothing to Disclose

Grace Ih, Abstract Co-Author: Nothing to Disclose

Alessandro D'Agnolo, Abstract Co-Author: Nothing to Disclose

Alan Waxman, Abstract Co-Author: Nothing to Disclose

To qualitatively and quantitatively compare the recommended 4hr scan protocol to the delayed 72hr and 7day scan for detection of pathology proven neuroendocrine tumors with In-111 Pentetrotide scintigraphy; and to determine the time point which provides the maximum information.

Three expert readers independently evaluated 120 whole body In-111-Pentetreotide scans, randomly sorted from the 4hr, 72hr, and 7day (6mci In-111 Pentetrotide at 8cm/min scans) of 40 patients referred to our institution. Patient identifiers were eliminated to blind readers from comparing studies from the same patient. Each reviewer graded areas of uptake by number, location, and intensity with liver being the internal background control. Comparisons of total number of lesions detected and their intensity were made. To quantify the data, 23 patients with pathology proven neuroendocrine tumors of the 40 had regions of interest (ROI) drawn around each lesion as well as a ROI adjacent background liver. An average count/pixel was determined for each ROI and Target/Background (T/B) ratios calculated at 4hr, 72hr and 7 day. The percent change from the 4hr T/B was then calculated for the 72hr and 7day study. The mean and standard deviation for all sites were calculated using a t-test comparison.

For 40 patients between the 3 readers: the 72hr study detected greater intensity and/or more lesions than the 4hr study in an average of 14(35%) more patients; the 7 day study detected greater intensity and/or more lesions than the 4hr study in an average of 9(22.5%) more patients; and the 7day study detected greater intensity and/or more lesions than the 72hr study in an average of 6.6(16.5%) more patients. Mean differences of quantified T/B ratios of all the positive studies between the 72hr vs 4hr studies and 7day vs 4hr studies were +62% (p-value=0.005) and +55% (p-value=0.003) respectively.

The 72hr and 7 day In-111-Pentetreotide scan are significantly more sensitive than the recommended 4hr octreotide scan for detection of pathology proven neuroendocrine tumors.

In-111-Pentetreotide imaging is optimized for detection of neuroendocrine tumors at the 72hr or greater. The recommended 4hr scan is inadequate

Young, S, Lee, J, Corbilla, R, Ih, G, D'Agnolo, A, Waxman, A, Delayed In-111-Pentetreotide Imaging Improves Neuroendocrine Tumor Detection.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5011914.html