Intraoperative molecular imaging clinical trials: a review of 2020 conference proceedings.

SIGNIFICANCE: Surgery is often paramount in the management of many solid organ malignancies because optimal resection is a major factor in disease-specific survival. Cancer surgery has multiple challenges including localizing small lesions, ensuring negative surgical margins around a tumor, adequately staging patients by discriminating positive lymph nodes, and identifying potential synchronous cancers. Intraoperative molecular imaging (IMI) is an emerging potential tool proposed to address these issues. IMI is the process of injecting patients with fluorescent-targeted contrast agents that highlight cancer cells prior to surgery. Over the last 5 to 7 years, enormous progress has been achieved in tracer development, near-infrared camera approvals, and clinical trials. Therefore, a second biennial conference was organized at the University of Pennsylvania to gather surgical oncologists, scientists, and experts to discuss new investigative findings in the field. Our review summarizes the discussions from the conference and highlights findings in various clinical and scientific trials. AIM: Recent advances in IMI were presented, and the importance of each clinical trial for surgical oncology was critically assessed. A major focus was to elaborate on the clinical endpoints that were being utilized in IMI trials to advance the respective surgical subspecialties. APPROACH: Principal investigators presenting at the Perelman School of Medicine Abramson Cancer Center's second clinical trials update on IMI were selected to discuss their clinical trials and endpoints. RESULTS: Multiple phase III, II, and I trials were discussed during the conference. Since the approval of 5-ALA for commercial use in neurosurgical malignancies, multiple tracers and devices have been developed to address common challenges faced by cancer surgeons across numerous specialties. Discussants also presented tracers that are being developed for delineation of normal anatomic structures that can serve as an adjunct during surgical procedures. CONCLUSIONS: IMI is increasingly being recognized as an improvement to standard oncologic surgical resections and will likely advance the art of cancer surgery in the coming years. The endpoints in each individual surgical subspecialty are varied depending on how IMI helps each specialty solve their clinical challenges.

A Pilot Comparison of Multispectral Fluorescence to Indocyanine Green Videoangiography and Other Modalities for Intraoperative Assessment in Vascular Neurosurgery.

BACKGROUND: Digital subtraction angiography (DSA) is the gold standard for vascular imaging, but is not easily integrated into a continuous microsurgical environment. Other available modalities for intraoperative vascular assessment have their own limitations. OBJECTIVE: To investigate multispectral fluorescence (MFL), a new technology based on indocyanine green (ICG) fluorescence, which may provide advantages over current intraoperative imaging modalities. METHODS: Cadaveric intracranial aneurysm models and turkey wing bypasses were created and tested with white light and micro-Doppler ultrasound, indocyanine green videoangiography (ICG-VA), MFL, and DSA in conditions mimicking surgery. Assessments with these modalities were scored by 7 neurosurgeons. RESULTS: DSA was significantly better than other modalities in evaluating the vasculature (P < .0001), but was significantly less ergonomic and efficient (P < .0001). MFL and ICG-VA were not significantly different from each other. Both were significantly better than white light/micro-Doppler ultrasound in assessing occlusion and patency (P ≤ .011), and both were better than DSA in ergonomics and efficiency (P < .0001). CONCLUSION: MFL performs similarly to ICG-VA in a laboratory setting. Further study will be required to determine whether it compares favorably in the operating room. While DSA is the standard for cerebrovascular visualization, MFL and ICG are significantly more ergonomic and efficient.

A collaborative virtual reality environment for neurosurgical planning and training.

OBJECTIVE: We have developed a highly interactive virtual environment that enables collaborative examination of stereoscopic three-dimensional (3-D) medical imaging data for planning, discussing, or teaching neurosurgical approaches and strategies. MATERIALS AND METHODS: The system consists of an interactive console with which the user manipulates 3-D data using hand-held and tracked devices within a 3-D virtual workspace and a stereoscopic projection system. The projection system displays the 3-D data on a large screen while the user is working with it. This setup allows users to interact intuitively with complex 3-D data while sharing this information with a larger audience. RESULTS: We have been using this system on a routine clinical basis and during neurosurgical training courses to collaboratively plan and discuss neurosurgical procedures with 3-D reconstructions of patient-specific magnetic resonance and computed tomographic imaging data or with a virtual model of the temporal bone. Working collaboratively with the 3-D information of a large, interactive, stereoscopic projection provides an unambiguous way to analyze and understand the anatomic spatial relationships of different surgical corridors. In our experience, the system creates a unique forum for open and precise discussion of neurosurgical approaches. CONCLUSION: We believe the system provides a highly effective way to work with 3-D data in a group, and it significantly enhances teaching of neurosurgical anatomy and operative strategies.