title: Small portable interchangeable imager of fluorescence for fluorescence guided surgery and research.
abstract: Fluorescence guided surgery (FGS) is a developing field of surgical and oncologic research. Practically, FGS has shown useful applications in urologic surgery, benign biliary surgery, colorectal cancer liver metastasis resection, and ovarian cancer debulking. Most notably in in cancer surgery, FGS allows for the clear delineation of cancerous tissue from benign tissue. FGS requires the utilization of a fluorescent contrast agent and an intraoperative fluorescence imaging device (IFID). Currently available IFIDs are expensive, unable to work with multiple fluorophores, and can be cumbersome. This study aims to describe the development and utility of a small, cost-efficient, and interchangeable IFID made from commercially available components. Extensive research was done to design and construct a light-weight, portable, and cost-effective IFID. We researched the capabilities, size, and cost of several camera types and eventually decided on a near-infrared (NIR) charged couple device (CCD) camera for its overall profile. The small portable interchangeable imager of fluorescence (SPIIF) is a "scout" IFID system for FGS. The main components of the SPIIF are a NIR CCD camera with an articulating light filter. These components and a LED light source with an attached heat sink are mounted on a small metal platform. The system is connected to a laptop by a USB 2.0 cable. Pixielink © software on the laptop runs the system by controlling exposure time, gain, and image capture. After developing the system, we evaluated its utility as an IFID. The system weighs less than two pounds and can cover a large area. Due to its small size, it is easily made sterile by covering it with any sterile plastic sheet. To determine the system's ability to detect fluorescent signal, we used the SPIIF to detect indocyanine green under ex and in-vivo conditions and fluorescein under ex-vivo conditions. We found the SPIIF was able to detect both ICG and fluorescein under different depths of a semi-opaque colloid. Second, we found that a concentration as low as 0.5 g/ml of indocyanine green dissolved in plasma was detectable. Lastly, in a murine and human cancer model, the SPIIF was able to detect indocyanine green signal within tumors and generate a signal-to-background ratio (SBR) of 3.75. This study shows that a low-cost IFID can be made from commercially available parts. Second, this IFID is capable of in and ex-vivo detection of multiple fluorophores without sacrificing its small size or favorable ergonomics.
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA Olugbenga.Okusanya@uphs.upenn.edu.
authors.forename: Olugbenga T
authors.initials: OT
authors.lastname: Okusanya
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Brian
authors.initials: B
authors.lastname: Madajewski
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Erin
authors.initials: E
authors.lastname: Segal
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Judy
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Ollin G
authors.initials: OG
authors.lastname: Venegas
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Judy
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Jon G
authors.initials: JG
authors.lastname: Quatromoni
authors.affiliation: Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia.
authors.forename: May D
authors.initials: MD
authors.lastname: Wang
authors.affiliation: Departments of Biomedical Engineering and Chemistry, Emory University, Atlanta, Georgia.
authors.forename: Shuming
authors.initials: S
authors.lastname: Nie
authors.affiliation: Thoracic Surgery Research Laboratory, Department of Surgery, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA.
authors.forename: Sunil
authors.initials: S
authors.lastname: Singhal
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000601:surgery*; D018827:Carcinoma, Lewis Lung / Q000175:diagnosis / Q000601:surgery*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000601:surgery*; D045744:Cell Line, Tumor; D005260:Female; D019793:Fluorescein; D005456:Fluorescent Dyes; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D008810:Mice, Inbred C57BL; D008875:Middle Aged; D009368:Neoplasm Transplantation; D061848:Optical Imaging / Q000295:instrumentation*; D012516:Osteosarcoma / Q000175:diagnosis / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*
chemical_list: D005456:Fluorescent Dyes; D007208:Indocyanine Green; D019793:Fluorescein
keywords: Fluorescence guided surgery; Indocyanine green; Intraoperative imaging; Near infrared.