Rianne Verhees MD, Presenter: Nothing to Disclose

M. de Jong MD, Abstract Co-Author: Nothing to Disclose

G L Beets MD, PhD, Abstract Co-Author: Nothing to Disclose

M F von Meyenfeldt MD, PhD, Abstract Co-Author: Nothing to Disclose

J M Van Engelshoven MD, PhD, Abstract Co-Author: Nothing to Disclose

Regina G. H. Beets-Tan MD, PhD, Abstract Co-Author: Nothing to Disclose

To asses the accuracy of ultra small iron oxide (USPIO)-MR imaging for the detection of nodal metastases in patients with primary rectal cancer.

13 patients with primary rectal cancer underwent preoperative local staging with phase array MRI at 1.5T. T2W fast SE and T2*W GRE sequences were performed before and after USPIO contrast enhancement. A radiologist experienced in pelvic MR reading evaluated prospectively the images. Both contrast enhanced and not enhanced sequences were simultaneously read. All mesorectal nodes were recorded on a standard pelvic-node-sheet. Nodal status prediction was given per patient. After TME surgery an expert pathologist evaluated the resection specimen according to the standard (Quirke) method. Side by side comparison together with the radiologist was done to obtaine an accurate node by node analysis

146 mesorectal nodes in 13 patients were harvested. 20 out of 146 were node positives (7/13 patiens). The sensitivity, specitivity, PPV and NPV for the detection of mesorectal nodal metastases were; 74% (20/20+7), 92% (109/109+10), 67% (20/20+10), 94% (109/109+7). On a patient bases the sensitivity, specitivity, PPV and NPV for the detection of mesorectal nodal metastases were; 100% (8/8+0), 80% (4/4+1), 89% (8/8+1), 100% (4/4+0).

This pilot study in a limited number of patients suggests that USPIO MR imaging could be valuable for the detection of nodal metastases in patients with primary rectal cancer and shows a high accuracy for the prediction of N0 status. The latter is useful for the selection of low risk rectal cancer patients without nodal involvement in whom surgical treatment alone might be adequate and radiotherapy could be withheld

Verhees, R, de Jong, M, Beets, G, von Meyenfeldt, M, Van Engelshoven, J, Beets-Tan, R, How Accurate Can We Predict the Nodal Status in Primary Rectal Cancer Using USPIO MRI?.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4410926.html