Page 136 - Fluorescence-guided cancer surgery

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Chapter 9
ABSTRACT
Introduction: Intraoperative uorescence imaging of the folate-receptor alpha (FRα) could support completeness of resection in cancer surgery. Feasibility of EC17, a FRα-targeting agent that uoresces at 500nm, was demonstrated in a limited series of ovarian cancer patients. Our objective was to evaluate EC17 in a larger group of ovarian cancer patients. In addition, we assessed the feasibility of EC17 in patients with breast cancer.
Methods: Two-to-three hours before surgery 0.1mg/kg EC17 was intravenously administered to 12 patients undergoing surgery for ovarian cancer and to 3 patients undergoing surgery for biopsy-proven FRα-positive breast cancer. The number of lesions/positive margins detected with uorescence and concordance between uorescence and tumor- and FRα-status was assessed in addition to safety and pharmacokinetics.
Results: Fluorescence imaging in ovarian cancer patients allowed detection of 57 lesions of which 44 (77%) appeared malignant on histopathology. Seven out of these 44 (16%) were not detected with inspection/palpation. Histopathology demonstrated concordance between uorescence and FRα- and tumor status. Fluorescence imaging in breast cancer patients, allowed detection of tumor- speci c uorescence signal. At the 500nm wavelength, auto uorescence of normal breast tissue was present to such extent that it interfered with tumor identi cation.
Conclusions: FRα is a favorable target for uorescence-guided surgery as EC17 produced a clear uorescent signal in ovarian and breast cancer tissue. This resulted in resection of ovarian cancer lesions that were otherwise not detected. Notwithstanding, auto uorescence caused false-positive lesions in ovarian cancer and di culty in discriminating breast cancer-speci c uorescence from background signal. Optimization of the 500nm uorophore, will minimize auto uorescence and further improve intraoperative tumor detection.