Barry Benson Goldberg MD, Presenter: Nothing to Disclose

Daniel Arthur Merton, Abstract Co-Author: Nothing to Disclose

Ji-Bin Liu MD, Abstract Co-Author: Nothing to Disclose

Mohan Aaruva PhD, Abstract Co-Author: Nothing to Disclose

Boby Mathew- PhD, Abstract Co-Author: Nothing to Disclose

Kaijun Zhang, Abstract Co-Author: Nothing to Disclose

Mathew L. Thakur PHD, Abstract Co-Author: Nothing to Disclose

Flemming Forsberg PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To determine the accuracy of lymphosonography {i.e., ultrasound imaging (US) after peritumoral injection of an ultrasound contrast agent}used for the detection of sentinel lymph nodes (SLNs) in swine with naturally occurring melanoma tumors and to compare the US results to lymphoscintigraphy using injection of blue dye with surgical dissection as the gold standard.

Twelve Sinclair swine with 28 melanomas were evaluated. Sonazoid (GE Healthcare, Oslo, Norway) was administered in 4 sites around each melanoma (1 ml total dosage). Gray scale phase-inversion harmonic US was performed with an Elegra system and 7.5 MHz probe (Siemens Medical, Issaquah, WA). Lymphoscintigraphy was performed after peritumoral injections of Tc99m with a Starcam 300 (GE Healthcare, Milwaukee, WI). Peritumoral injections of blue dye were performed around each melanoma and the dye-filled lymphatic channels (LCs) were used to locate SLNs and, in some cases, second echelon nodes. The accuracy of SLN detection with the two imaging methods was compared using the sign test.

Lymphosonography identified 55 SLNs (including 1 false positive) while lymphoscintigraphy identified 38 "hot spots" suspected of representing SLNs (including 2 false positives and 2 second-echelon nodes). Blue dye-guided surgical dissection identified 62 lymph nodes of which 2 were determined to represent second echelon nodes (i.e., blue dye was identified in efferent LCs emanating from SLNs to the blue dye-stained nodes). The SLNs detected ranged in size from 3 mm to 32 mm. Twenty-one of the 26 nodes not seen with lymphoscintigraphy were detected with lymphosonography, whereas only 1 SLN detected with lymphoscintigraphy was not detected by lymphosonography. The accuracy of SLN detection was 90% (54/60) for lymphosonography, which was significantly higher than the 57% (34/60) achieved with lymphoscintigraphy (p= 0.0164).

Lymphosonography was statistically better than lymphoscintigraphy for the detection of SLNs in this animal model. This research was funded by a grant from GE Healthcare, Oslo, Norway and by NIH CA100370.

B.B.G.: Received grant funding from GE Healthcare to support this research.

Goldberg, B, Merton, D, Liu, J, Aaruva, M, Mathew-, B, Zhang, K, Thakur, M, Forsberg, F, et al, , Detection of Sentinel Lymph Nodes in Swine with Melanoma Tumors: Comparison of Contrast-enhanced US, Nuclear Medicine, and Blue Dye with Surgical Dissection.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4412530.html