Ex vivo detection of tumoral lymph nodes of colorectal origin with fluorescence imaging after intraoperative intravenous injection of indocyanine green.
OBJECTIVE
The aim of this study was to investigate the potential role of indocyanine green (ICG) fluorescence imaging after intraoperative intravenous (IV) injection for the "ex vivo" detection of metastatic lymph nodes (mLNs) of colorectal cancer origin.


METHODS
Fresh-fixed LNs in cassettes and/or paraffin-embedded LNs of patients included in a study that evaluated the role of ICG in the detection of peritoneal metastases of colorectal origin (Protocol NCT-01995591) were further explored with a dedicated near-infrared camera system for their fluorescence. An IV injection of ICG was delivered intraoperatively at 0.25 mg/kg. Signal to background ratios (SBRs) were calculated.


RESULTS
LNs on operative specimens were evaluated for 12 patients (5 males, 7 females). A total of 182 LNs were analyzed. The mean LN number per patient was 15.2 (median: 15.5; range 3-22). SBRs of mLNs were significantly more fluorescent than benign LNs, 1.41 versus 1.04 arbitrary units (P < 0.0002). On univariate analysis, fluorescence was statistically correlated with LN surface area (>20 mm(2) ) (P < 0.0004).


CONCLUSIONS
Ex vivo ICG fluorescence imaging after intraoperative IV injection represents a potential method for detecting invaded LN's of colorectal cancer origin on operative specimens. Further clinical studies are needed to better define optimal techniques. J. Surg. Oncol. 2016;114:348-353. © 2016 Wiley Periodicals, Inc.
Department of Surgical Oncology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Gabriel
G
Liberale
Department of Pathology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Maria Gomez
MG
Galdon
Data Centre and Statistics Department, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Michel
M
Moreau
Department of Nuclear Medicine and Clinic-Unit of Lymphology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Sophie
S
Vankerckhove
Department of Surgical Oncology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Issam
I
El Nakadi
Department of Pathology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Denis
D
Larsimont
Department of Surgical Oncology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Vincent
V
Donckier
Department of Nuclear Medicine and Clinic-Unit of Lymphology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium.
Pierre
P
Bourgeois
D000368:Aged; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D005456:Fluorescent Dyes; D006801:Humans; D007208:Indocyanine Green; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061848:Optical Imaging; D010534:Peritoneal Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D012680:Sensitivity and Specificity
D005456:Fluorescent Dyes; D007208:Indocyanine Green
colorectal neoplasms; ex vivo; fluorescence imaging; indocyanine green; lymph nodes; metastatic