Leiden University Scholarly Publications

Persistent URL of this record https://hdl.handle.net/1887/118847

In Collections

This item can be found in the following collections:

Vorst, J.R. van der; Hutteman, M.; Mieog, J.S.D.; Rooij, K.E. de; Kaijzel, E.L.; Lowik, C.W.G.M.; ... ; Vahrmeijer, A.L. (2011)

Near-Infrared Fluorescence Imaging of Liver Metastases in Rats using Indocyanine Green

Article / Letter to editor
BACKGROUND: Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) is a promising technique to obtain real-time assessment of the extent and number of colorectal liver metastases during surgery. The current study aims to optimize dosage and timing of ICG administration. MATERIALS AND METHODS: Liver tumors were induced in 18 male WAG/Rij rats by subcapsular inoculation of CC531 rat colorectal cancer cells into three distinct liver lobes. Rats were divided in two groups: imaging after 24 and 48 h or 72 and 96 h after intravenous ICG administration. In each time group, rats were allocated to three dose groups: 0.04, 0.08, or 0.16 mg ICG. Intraoperative imaging and ex vivo measurements were performed using the Mini-FLARE imaging system and confirmed by fluorescence microscopy. Fluorescence intensity was quantified using the Mini-FLARE software and the difference between tumor signal and liver signal (tumor-to-liver ratio; TLR) was calculated. RESULTS: In all 18 rats, all...Show moreBACKGROUND: Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) is a promising technique to obtain real-time assessment of the extent and number of colorectal liver metastases during surgery. The current study aims to optimize dosage and timing of ICG administration. MATERIALS AND METHODS: Liver tumors were induced in 18 male WAG/Rij rats by subcapsular inoculation of CC531 rat colorectal cancer cells into three distinct liver lobes. Rats were divided in two groups: imaging after 24 and 48 h or 72 and 96 h after intravenous ICG administration. In each time group, rats were allocated to three dose groups: 0.04, 0.08, or 0.16 mg ICG. Intraoperative imaging and ex vivo measurements were performed using the Mini-FLARE imaging system and confirmed by fluorescence microscopy. Fluorescence intensity was quantified using the Mini-FLARE software and the difference between tumor signal and liver signal (tumor-to-liver ratio; TLR) was calculated. RESULTS: In all 18 rats, all colorectal liver metastases (n = 34), some as small as 1.2 mm, were identified using ICG and the Mini-FLARE imaging system. Average tumor-to-liver ratio (TLR) over all groups was 3.0 ± 1.2. TLR was significantly higher in the 72 h time group compared with other time points. ICG dose did not significantly influence TLR, but a trend was found favoring the 0.08 mg dose group. Fluorescence microscopy demonstrated a clear fluorescent rim around the tumor. CONCLUSIONS: This study demonstrates that colorectal cancer liver metastases can be clearly identified during surgery using ICG and the Mini-FLARE imaging system, with optimal timing of 72 h post-injection and an optimal dose of 0.08 mg (0.25 mg/kg) ICG. NIR fluorescence imaging has the potential to improve intraoperative detection of micrometastases and, thus, the completeness of resection.Show less
All authors
Vorst, J.R. van der; Hutteman, M.; Mieog, J.S.D.; Rooij, K.E. de; Kaijzel, E.L.; Lowik, C.W.G.M.; Putter, H.; Kuppen, P.J.K.; Frangioni, J.V.; Velde, C.J.H. van de; Vahrmeijer, A.L.
Date
2011-02-02
Journal
Journal of Surgical Research
DOI
doi:10.1016/j.jss.2011.01.009