Page 42 - Fluorescence-guided cancer surgery

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Chapter 3
ABSTRACT
Background: Despite recent developments in preoperative breast cancer imaging, intraoperative localization of tumor tissue can be challenging, resulting in tumor-positive resection margins during breast conserving surgery. Based on certain physicochemical similarities between Technetium(99mTc)-sestamibi (MIBI), an SPECT radiodiagnostic with a sensitivity of 83-90% to detect breast cancer preoperatively, and the near-infrared (NIR) uorophore Methylene Blue (MB), we hypothesized that MB might detect breast cancer intraoperatively using NIR uorescence imaging.
Methods: Twenty-four patients with breast cancer, planned for surgical resection, were included. Patients were divided in 2 administration groups, which di ered with respect to the timing of MB administration. N = 12 patients per group were administered 1.0 mg/kg MB intravenously either immediately or 3 h before surgery. The mini-FLARE imaging system was used to identify the NIR uorescent signal during surgery and on post-resected specimens transferred to the pathology department. Results were con rmed by NIR uorescence microscopy.
Results: 20/24 (83%) of breast tumors (carcinoma in N=21 and ductal carcinoma in situ in N=3) were identi ed in the resected specimen using NIR uorescence imaging. Patients with non-detectable tumors were signi cantly older. No signi cant relation to receptor status or tumor grade was seen. Overall tumor- to-background ratio (TBR) was 2.4 ± 0.8. There was no signi cant di erence between TBR and background signal between administration groups. In 2/4 patients with positive resection margins, breast cancer tissue identi ed in the wound bed during surgery would have changed surgical management. Histology con rmed the concordance of uorescence signal and tumor tissue.
Conclusions: This feasibility study demonstrated an overall breast cancer identi cation rate using MB of 83%, with real-time intraoperative guidance having the potential to alter patient management.