Preclinical evaluation of robotic-assisted sentinel lymph node fluorescence imaging

Michael A Liss; Salman Farshchi-Heydari; Zhengtao Qin; Sean A Hickey; David J Hall; Christopher J Kane; David R Vera

doi:10.2967/jnumed.114.140871

Preclinical evaluation of robotic-assisted sentinel lymph node fluorescence imaging

J Nucl Med. 2014 Sep;55(9):1552-6. doi: 10.2967/jnumed.114.140871. Epub 2014 Jul 14.

Authors

Michael A Liss¹, Salman Farshchi-Heydari², Zhengtao Qin³, Sean A Hickey⁴, David J Hall², Christopher J Kane⁵, David R Vera⁶

Affiliations

¹ Department of Urology, University of California, San Diego, La Jolla, California UCSD Moores Cancer Center. University of California, San Diego, La Jolla, California.
² Department of Radiology, University of California, San Diego, La Jolla, California UCSD In Vivo Cancer and Molecular Imaging Center, University of California, San Diego, La Jolla, California.
³ Department of Radiology, University of California, San Diego, La Jolla, California UCSD In Vivo Cancer and Molecular Imaging Center, University of California, San Diego, La Jolla, California Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California; and.
⁴ Department of Surgery, University of California, San Diego, La Jolla, California.
⁵ Department of Urology, University of California, San Diego, La Jolla, California UCSD Moores Cancer Center. University of California, San Diego, La Jolla, California Department of Surgery, University of California, San Diego, La Jolla, California.
⁶ UCSD Moores Cancer Center. University of California, San Diego, La Jolla, California Department of Radiology, University of California, San Diego, La Jolla, California UCSD In Vivo Cancer and Molecular Imaging Center, University of California, San Diego, La Jolla, California Department of Surgery, University of California, San Diego, La Jolla, California [email protected].

Abstract

An ideal substance to provide convenient and accurate targeting for sentinel lymph node (SLN) mapping during robotic-assisted surgery has yet to be found. We used an animal model to determine the ability of the FireFly camera system to detect fluorescent SLNs after administration of a dual-labeled molecular imaging agent.

Methods: We injected the footpads of New Zealand White rabbits with 1.7 or 8.4 nmol of tilmanocept labeled with (99m)Tc and a near-infrared fluorophore, IRDye800CW. One and 36 h after injection, popliteal lymph nodes, representing the SLNs, were dissected with the assistance of the FireFly camera system, a fluorescence-capable endoscopic imaging system. After excision of the paraaortic lymph nodes, which represented non-SLNs, we assayed all lymph nodes for radioactivity and fluorescence intensity.

Results: Fluorescence within all popliteal lymph nodes was easily detected by the FireFly camera system. Fluorescence within the lymph channel could be imaged during the 1-h studies. When compared with the paraaortic lymph nodes, the popliteal lymph nodes retain greater than 95% of the radioactivity at both 1 and 36 h after injection. At both doses (1.7 and 8.4 nmol), the popliteal nodes had higher (P < 0.050) optical fluorescence intensity than the paraaortic nodes at the 1- and 36-h time points.

Conclusion: The FireFly camera system can easily detect tilmanocept labeled with a near-infrared fluorophore at least 36 h after administration. This ability will permit image acquisition and subsequent verification of fluorescence-labeled SLNs during robotic-assisted surgery.

Keywords: fluorescent tilmanocept; robotic-assisted surgery; sentinel lymph node mapping.

MeSH terms

Animals
Lymph Node Excision
Rabbits
Robotics / methods*
Sentinel Lymph Node Biopsy / methods*
Spectrometry, Fluorescence

Abstract

MeSH terms

Grants and funding