Background/Aim: Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) is used to visualize colon-cancer liver metastases (CCLM) during surgery. The present study aimed to use ICG to visualize small CCLM in an orthotopic mouse model. Materials and Methods: A 3-mm fragment of HT29 human colon cancer was implanted to the liver of 5 athymic nude mice (nu/nu). The Pearl Trilogy Small Animal Fluorescence Imaging system was used 24 h after intravenous (IV) injection of 0.025 mg (0.25 mg/ml) ICG. Results: In four of the five mice, tumor fluorescence was detected. Small tumors (approximately 3 mm) were distinctly visualized with a minimal fluorescence liver signal, with a mean tumor to liver signal ratio of 1.81 (SD±0.167). Conclusion: Small CCLM can be clearly identified by ICG fluorescence in an orthotopic nude-mouse model. This model is translatable to the clinic for the detection of occult early CCLM.

中文翻译：

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吲哚菁绿标记极早期结肠癌肝转移的原位裸鼠模型

背景/目的：使用吲哚菁绿 (ICG) 的近红外 (NIR) 荧光成像用于在手术期间可视化结肠癌肝转移 (CCLM)。本研究旨在使用 ICG 在原位小鼠模型中可视化小型 CCLM。材料和方法：将 3 毫米的 HT29 人结肠癌片段植入 5 只无胸腺裸鼠 (nu/nu) 的肝脏。在静脉 (IV) 注射 0.025 mg (0.25 mg/ml) ICG 后 24 小时使用 Pearl Trilogy 小动物荧光成像系统。结果：在五只小鼠中的四只中检测到肿瘤荧光。小肿瘤（约 3 毫米）清晰可见，具有最小的肝脏荧光信号，平均肿瘤与肝脏信号比为 1.81 (SD±0.167)。结论：在原位裸鼠模型中，ICG 荧光可以清楚地识别小 CCLM。