Digital dynamic discrimination of primary colorectal cancer using systemic indocyanine green with near-infrared endoscopy.

As indocyanine green (ICG) with near-infrared (NIR) endoscopy enhances real-time intraoperative tissue microperfusion appreciation, it may also dynamically reveal neoplasia distinctively from normal tissue especially with video software fluorescence analysis. Colorectal tumours of patients were imaged mucosally following ICG administration (0.25 mg/kg i.v.) using an endo-laparoscopic NIR system (PINPOINT Endoscopic Fluorescence System, Stryker) including immediate, continuous in situ visualization of rectal lesions transanally for up to 20 min. Spot and dynamic temporal fluorescence intensities (FI) were quantified using ImageJ (including videos at one frame/second, fps) and by a bespoke MATLAB® application that provided digitalized video tracking and signal logging at 30fps (Fluorescence Tracker App downloadable via MATLAB® file exchange). Statistical analysis of FI-time plots compared tumours (benign and malignant) against control during FI curve rise, peak and decline from apex. Early kinetic FI signal measurement delineated discriminative temporal signatures from tumours (n = 20, 9 cancers) offering rich data for analysis versus delayed spot measurement (n = 10 cancers). Malignant lesion dynamic curves peaked significantly later with a shallower gradient than normal tissue while benign lesions showed significantly greater and faster intensity drop from apex versus cancer. Automated tracker quantification efficiently expanded manual results and provided algorithmic KNN clustering. Photobleaching appeared clinically irrelevant. Analysis of a continuous stream of intraoperatively acquired early ICG fluorescence data can act as an in situ tumour-identifier with greater detail than later snapshot observation alone. Software quantification of such kinetic signatures may distinguish invasive from non-invasive neoplasia with potential for real-time in silico diagnosis.

Visual probing of rectal neoplasia: near-infrared interrogation of primary tumors and secondary lymph nodes.

Laparoscopic and endoscopic colorectal intervention and operations have their basis in real-time, image-based decision-making and step-by-step sequenced technical progress. The capacity to visualize accurately malignant disease wherever it may be including within the primary lesion and its draining lymph node basin as well as at potential sites of metastatic harbor (i.e. peritoneum, liver and lung) would allow more accurate surgery at the time of operation and enable personalized, stratified surgical intervention. In addition, such capacity could efficiently compress the diagnostic and therapeutic stages of a patient's progress from presentation, through work-up and onto appropriate treatment, important in this era of restricted resource and increased user demand. Near-infrared endolaparoscopic illumination enables broad spectral imaging of tissue in situ, most often, at present, in conjunction with the approved safe and low-cost fluorophore indocyanine green. While additional targeted agents are in development, here we detail how this developed and available technology may be used as a visual probe of neoplasia to inform surgeons regarding functional, tissue characterization through the direct observation of metabolic and metabolomic processes within the area under inspection perhaps helping in the distinction between invasive cancer and non-invasive dysplastic lesions. This understanding can inform and accelerate development of specific agents and techniques that can better advance surgical practice into the era of surgical data science and true precision surgery.