TY - JOUR TI - A phantom based study of short-wave infrared emitting nanocomposites as contrast agents for fluorescence guided surgery DO - https://doi.org/doi:10.7282/t3-489t-6e96 PY - 2019 AB - Accurate, real-time detection and characterization of cancerous lesions is essential for effective surgical resection that both minimizes the chance of recurrence and preserves healthy tissue. In multiple ongoing clinical trials, optically-guided surgical techniques are utilizing fluorescent probes that emit light in the near infrared (NIR) window. Use of NIR light is motivated by lower scattering and autofluorescence in biological tissues than UV or visible light which results in improved imaging depth, contrast, and resolution. Because scattering monotonically decreases with increasing wavelength, several groups have hypothesized that probes emitting at the longer wavelengths in the short-wave infrared (SWIR) window may enable even deeper tissue imaging and greater resolution / contrast. This thesis is focused on engineering an imaging system for fluorescence guided surgery in small animal models using SWIR-emitting human serum albumin encapsulated rare-earth nanocomposites (ReANCs). LabVIEW software controls the illumination, scanning, and imaging hardware components and provides real-time visualization of SWIR emissions overlaid on anatomical (white light) images. A separate Matlab graphical user interface (GUI) was developed to enable quantitative post-processing of images acquired from the SWIR platform. To validate the SWIR imager, a phantom study comparing the attainable imaging depth and resolution when using ReANCs versus the FDA-approved NIR fluorophore indocyanine green (ICG) versus white light was conducted. Tissue-mimicking gelatin phantoms were created with embedded agarose inclusions containing the contrast agent of interest. Inclusion depth, size, and shape were all varied, and inclusion contrast was quantified from SWIR and NIR images of the intact phantoms. Post-imaging, the inclusions were resected under SWIR, NIR, or white light guidance. The resected inclusions and inclusion cavities were then imaged to analyze resection accuracy for each guidance method. A pilot in vivo animal study was performed using female athymic homozygous nude mice injected with Erbium-doped ReANCs. Imaging with the SWIR setup provided insight into future animal work. The cumulative findings of this thesis lay the groundwork for the design of a real-time imager that facilitates fluorescence-guided, deep tissue surgery, which has the potential to improve accuracy of tumor resection and decrease the chance of cancer recurrence. KW - Optical imaging KW - Biomedical Engineering KW - Diagnostic imaging KW - Near infrared spectroscopy LA - English ER -