Development and evaluation of a connective tissue phantom model for subsurface visualization of cancers requiring wide local excision

• Published in: Journal of biomedical optics 2017-12, Vol.22 (12), p.121613-121613
• Main Authors: Samkoe, Kimberley S, Bates, Brent D, Tselepidakis, Niki N, DSouza, Alisha V, Gunn, Jason R, Ramkumar, Dipak B, Paulsen, Keith D, Pogue, Brian W, Henderson, Eric R
• Format: Article
• Language: English
• Subjects: Special Section on Translational Biophotonics
• ISSN: 1083-3668; 1560-2281
• DOI: 10.1117/1.JBO.22.12.121613

Wide local excision (WLE) of tumors with negative margins remains a challenge because surgeons cannot directly visualize the mass. Fluorescence-guided surgery (FGS) may improve surgical accuracy; however, conventional methods with direct surface tumor visualization are not immediately applicable, and properties of tissues surrounding the cancer must be considered. We developed a phantom model for sarcoma resection with the near-infrared fluorophore IRDye 800CW and used it to iteratively define the properties of connective tissues that typically surround sarcoma tumors. We then tested the ability of a blinded surgeon to resect fluorescent tumor-simulating inclusions with ∼1-cm margins using predetermined target fluorescence intensities and a Solaris open-air fluorescence imaging system. In connective tissue-simulating phantoms, fluorescence intensity decreased with increasing blood concentration and increased with increasing intralipid concentrations. Fluorescent inclusions could be resolved at ≥1-cm depth in all inclusion concentrations and sizes tested. When inclusion depth was held constant, fluorescence intensity decreased with decreasing volume. Using targeted fluorescence intensities, a blinded surgeon was able to successfully excise inclusions with ∼1-cm margins from fat- and muscle-simulating phantoms with inclusion-to-background contrast ratios as low as 2∶1. Indirect, subsurface FGS is a promising tool for surgical resection of cancers requiring WLE.