Sentinel lymph node mapping of the gastrointestinal tract by using invisible light.
BACKGROUND
Because many gastrointestinal (GI) tumors spread by way of lymphatics, histological assessment of the first draining lymph nodes has both prognostic and therapeutic significance. However, sentinel lymph node mapping of the GI tract by using available techniques is limited by unpredictable drainage patterns, high background signal, and the inability to image lymphatic tracers relative to surgical anatomy in real time. Our goal was to develop a method for patient-specific intraoperative sentinel lymph node mapping of the GI tract by using invisible near-infrared light.


METHODS
We developed an intraoperative near-infrared fluorescence imaging system that simultaneously displays surgical anatomy and otherwise invisible near-infrared fluorescence images of the surgical field. Near-infrared fluorescent quantum dots were injected intraparenchymally into the stomach, small bowel, and colon, and draining lymphatic channels and sentinel lymph nodes were visualized. Dissection was performed under real-time image guidance.


RESULTS
In 10 adult pigs, we demonstrated that 200 pmol of quantum dots quickly and accurately map lymphatic drainage and sentinel lymph nodes. Injection into the mid jejunum and colon results in fluorescence of a single lymph node at the root of the bowel mesentery. Injection into the stomach resulted in identification of a retrogastric node. Histological analysis in all cases confirmed the presence of nodal tissue.


CONCLUSIONS
We report the use of invisible near-infrared light for intraoperative sentinel lymph node mapping of the GI tract. This technology overcomes the limitations of currently available methods, permits patient-specific imaging of lymphatic flow and sentinel nodes, and provides highly sensitive, real-time image-guided dissection.
Soltesz
Edward G
EG
Department of Surgery, Brigham and Women's Hospital, 75 Francis Street, Boston, Massachusetts 02115, USA.
Kim
Sungjee
S
Kim
Sang-Wook
SW
Laurence
Rita G
RG
De Grand
Alec M
AM
Parungo
Cherie P
CP
Cohn
Lawrence H
LH
Bawendi
Moungi G
MG
Frangioni
John V
JV
D000818:Animals; D005260:Female; D005453:Fluorescence; D005770:Gastrointestinal Neoplasms / Q000473:pathology*; D007432:Intraoperative Period; D008027:Light; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008208:Lymphatic System; D008297:Male; D045663:Quantum Dots; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013552:Swine