Sunkuk Kwon BS, Abstract Co-Author: Nothing to Disclose

Shi Ke MD, Abstract Co-Author: Nothing to Disclose

Wei Wang, Abstract Co-Author: Nothing to Disclose

Eva M. Sevick-Muraca PhD, Presenter: Nothing to Disclose

In the past, angiogenesis has provided a hallmark for characterizing cancers as well as several other diseases. Recently, the role of lymphoangiogenesis has been implicated in cancer. Yet to date there is no method for in vivo imaging of the lymph in small animal imaging. Herein we demonstrate preliminary optical imaging of both angiogenic vessels (through the targeting of integrin alpha v beta 3) and lymphatics associated with human Kaposi´s sarcoma (KS SLK).

KS SLK cells were implanted subcutaneously into the hind region of nude mice. Fluorescence imaging of the mice took place using 785 nm excitation illumination and 830 nm collection optics. Xenografts were imaged immediately after the injection of 111-In-DTPA-IRDye800-c(KRGDf) for a period of 40 min, and every 24 hrs thereafter for up to 48 hrs. Scintigrams were also acquired. After 24 or 48 hrs following the initial injection of dual-labeled conjugate, Cy5.5 was injected into the rear left mouse foot using 27-gauge needle. After 40 minutes, fluorescence image guided lymphadenectomy was performed using 690 nm illumination and 710 nm collection optics. Histopathology was performed on excised samples.

Near-infrared fluorescence images and scintigrams showed the uptake of dual-labeled conjugate to alpha v beta 3 receptors expressed in KS SLK. Owing to the high signal to noise offered by fluorescence, dynamic imaging was possible. In addition, popliteal lymph node was imaged in the tumor region at 5 min after injection of Cy5.5 and successfully dissected as guided by red fluorescence imaging.

Real-time dynamic fluorescence imaging can be used not only to detect tumor region with the specifically targeted agents, but also to monitor the rapid distribution of the agents through the animal body due to its high sensitivity. In addition, multi-wavelength dynamic fluorescence imaging can be applied to characterize tumors with different fluorescent conjugates targeting different tissue compartments.

By imaging both angiogenic and lymph vasculatures and following response to treatment, a better understanding of disease progression can be translated into clinical practice.

Kwon, S, Ke, S, Wang, W, Sevick-Muraca, E, Imaging the Lymph Network and Alpha versus Beta 3 Receptor Expressed in a Xenografts of Kaposi Sarcoma.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4441244.html