Fig. 3.

Image-guided surgery in the visible and NIR-I or NIR-II windows. (A) (Upper) Color/visible imaging recorded during surgery. NIR-I fluorescence imaging (Middle) and NIR-II fluorescence imaging (Lower) of 4T1 tumor removal 24 h after i.v. injection of IRDye800-TRC105. Fluorescence was excited by an 808-nm laser. NIR-I and NIR-II emissions were collected in the 900- to 1,000-nm and 1,100- to 1,400-nm windows, respectively. The skin covering the tumor was resected initially to expose the tumor, and then the tumor was removed step by step. The largest FOV (44 × 34 mm²) of the zoomable lens set was used to guide surgery (step 1 to step 3). The tumor area marked by a rectangle in step 2 was locally magnified using the highest magnification (FOV: 22 × 18 mm²) of the zoomable lens set. (B) Normalized intensity profiles along the dotted lines in A. A strong body signal was left after tumor removal 24 h p.i. of IRDye800-TRC105. (C) T/M ratios of IRDye800-TRC105 in NIR-I and NIR-II windows. T/M ratios were calculated using the fluorescence intensity of tumor and muscle measured after skin resection (step 2 in A). Data in C are presented as box plots (center line, median; interquartile range, 25th and 75th percentiles; whiskers, 1.5 × SD; points, outliers).