Colorectal cancer is the fourth most diagnosed malignancy worldwide and surgery is one of the cornerstones of the treatment strategy. Near-infrared (NIR) fluorescence imaging is a new and upcoming technique, which uses an NIR fluorescent agent combined with a specialised camera that can detect light in the NIR range. It aims for more precise surgery with improved oncological outcomes and a reduction in complications by improving discrimination between different structures. A systematic search was conducted in the Embase, Medline and Cochrane databases with search terms corresponding to 'fluorescence-guided surgery', 'colorectal surgery', and 'colorectal cancer' to identify all relevant trials. The following clinical applications of fluorescence guided surgery for colorectal cancer were identified and discussed: (1) tumour imaging, (2) sentinel lymph node imaging, (3) imaging of distant metastases, (4) imaging of vital structures, (5) imaging of perfusion. Both experimental and FDA/EMA approved fluorescent agents are debated. Furthermore, promising future modalities are discussed. Fluorescence-guided surgery for colorectal cancer is a rapidly evolving field. The first studies show additional value of this technique regarding change in surgical management. Future trials should focus on patient related outcomes such as complication rates, disease free survival, and overall survival.
Laryngeal cancer is a prevalent head and neck malignancy, with poor prognosis and low survival rates for patients with advanced disease. Treatment consists of unimodal therapy through surgery or radiotherapy in early staged tumors, while advanced stage tumors are generally treated with multimodal chemoradiotherapy or (total) laryngectomy followed by radiotherapy. Still, the recurrence rate for advanced laryngeal cancer is between 25 and 50%. In order to improve surgical resection of laryngeal cancer and reduce local recurrence rates, various intraoperative optical imaging techniques have been investigated. In this systematic review, we identify these technologies, evaluating the current state and future directions of optical imaging for this indication. Narrow-band imaging (NBI) and autofluorescence (AF) are established tools for early detection of laryngeal cancer. Nonetheless, their intraoperative utility is limited by an intrinsic inability to image beyond the (sub-)mucosa. Likewise, contact endoscopy (CE) and optical coherence tomography (OCT) are technically cumbersome and only useful for mucosal margin assessment. Research on fluorescence imaging (FLI) for this application is sparse, dealing solely with nonspecific fluorescent agents. Evidently, the imaging modalities that have been investigated thus far are generally unsuitable for deep margin assessment. We discuss two optical imaging techniques that can overcome these limitations and suggest how they can be used to achieve adequate margins in laryngeal cancer at all stages.
The lymphatic system plays a crucial role in the spread of solid tumors and is often the first site of metastasis, as cancer cells typically invade nearby lymph nodes (LN) before potentially spreading to other LNs through the lymphatic system and distant organs through the bloodstream
Background/Objectives: Intraoperative fluorescence imaging (FI) with tumor-targeted tracers offers a promising approach to improve surgical precision in cancer surgery. cRGD-ZW800-1, an integrin-targeted fluorescent tracer, has previously demonstrated safety, tumor specificity, and utility in detecting inadequate margins in oral cancer. During this study, we observed variability in background fluorescence between different subsites of the oral cavity. Therefore, this study aimed to systematically evaluate intraoperative in vivo and ex vivo mucosal contrast ratios across various oral cavity subsites using FI with cRGD-ZW800-1. Methods: Thirty-one patients with oral squamous cell carcinoma underwent intraoperative FI following intravenous injection of cRGD-ZW800-1 at least 18 h preoperatively. In vivo imaging was performed using the Quest Spectrum platform. In addition, ex vivo FI of the resected specimen was performed using the Pearl Trilogy Small Animal Imaging System. As these ex vivo images were obtained under uniform and controlled acquisition conditions, they allow for direct comparison with the intraoperative fluorescence signals. Fluorescence intensities and tumor-to-background ratios (TBRs) were assessed per oral subsite using manually drawn regions of interest (ROIs) on the tumor and adjacent healthy mucosa using Quest’s Spectrum Software, version 4.8.2, (in vivo images) and the Pearl’s integrated software ImageStudio version 6.2 (ex vivo images). A TBR ≥ 1.5 was considered sufficient. Results: Under uniform imaging settings, all samples exhibited adequate contrast (TBR ≥ 2.3), allowing clear tumor visualization and precise evaluation of mucosal margins on final histopathology. Notably, intraoperative in vivo contrast in the posterior located maxillary alveolar process was comparatively lower, which was attributable to suboptimal imaging conditions and subsite-specific background fluorescence. Conclusions: Our findings indicate that, although contrast varies across different oral subsites, all specimens exhibited sufficient ex vivo mucosal contrast to allow reliable tumor delineation. As in vivo imaging may be affected by subsite-specific background fluorescence and inherent limitations of intraoperative imaging geometry, fluorescence signals should be interpreted in conjunction with standard visual and tactile assessment. Due to anatomical constraints, different oral subsites may appear within the same field of view, which can influence perceived signal intensity. Therefore, intraoperative ex vivo fluorescence evaluation is recommended for signal interpretation.