Breast-conserving surgery is facing the challenge of objective
tumor margin identification intraoperatively. Near-infrared fluorescence imaging would be an ideal approach to visualize
tumor margins during surgeries. In this preliminary study, the feasibility of
methylene blue-based near-infrared fluorescence imaging technique for
breast cancer detection was assessed in resected human breast specimens after
breast cancer surgeries. Thirty patients with
breast cancer scheduled for surgical treatment were enrolled, including 10 patients with preoperative
chemotherapy and 20 patients without. Each of them received an injection of 1 mg/kg
methylene blue intravenously 3 hours before the surgery. Then, a home-developed
methylene blue-specific near-infrared fluorescence imaging system was employed to image the resected breast tissues and identify the
tumor by the fluorescence contrast. Specimens were taken for pathological examinations as the reference. There were no severe adverse events attributable to
methylene blue. Of 20 patients, who did not receive preoperative
chemotherapy, 16 exhibited fluorescent contrast on their resected tissues (signal-to-background ratio: 1.94 ± 0.71). In contrast,
tumors were identified in 3 of 10 specimens from patients who underwent preoperative
chemotherapy (signal-to-background ratio: 1.63 ± 0.38). A total of 35 tissues were sampled from 30 specimens. Besides 30
tumor samples, 5 more suspicious samples with fluorescence signal were confirmed to be benign hemorrhagic tissues. Therefore, a sensitivity of 0.63 and a positive predictive value of 0.79 were achieved by the
methylene blue fluorescence imaging strategy. Here, we demonstrate the feasibility of using
methylene blue fluorescence imaging to identify
breast cancer. Preoperative
chemotherapy had an impact on imaging effect, which may reduce the detection rate. After all,
methylene blue fluorescence imaging has great potential to be used into
breast-conserving surgery for
tumor-positive margins detection, but further clinical trial study is needed ( http://www.chictr.org.cn/ Clinical Trial Registry ID: ChiCTR1800015400, Near-infrared fluorescence imaging applied in
breast cancer identification with
methylene blue).