Surgical guidance of soft tissue sarcoma excision using near-infrared Raman spectroscopy and autofluorescence imaging

Abstract

Soft tissue sarcomas (STS) are a rare and heterogeneous form of malignant tumors that arise from mesenchymal progenitors and are primarily treated through surgical resection and radiation. A positive surgical margin is the greatest predictor of local recurrence, however, margin statuses are often determined weeks after the surgery and can suffer from sampling error. This delayed process increases patient morbidity rates, increases healthcare costs, and indicates the need for a rapid and accurate tool that can provide surgeons with immediate feedback during surgery. Towards that goal, this thesis describes the ever in vivo study of near-infrared (NIR) autofluorescence and Raman spectroscopy within patients undergoing STS resections in which the presence of a high NIR autofluorescence signal within the human body was observed. This discovery lead to the development of a modular wide-field NIR autofluorescence imaging system that serves both as a robust laboratory based research platform and as an intraoperative surgical guidance tool. The unknown fluorophore responsible for the endogenous signal was then characterized and identified as hematoporphyrin based. The knowledge gathered from this dissertation has potential for revolutionizing STS tumor resections and many others by providing surgeons with a convenient and intuitive tool for accurately identifying and locating residual cancers during surgery.