No abstract

Endoscopic resection of sinonasal squamous cell carcinoma has become the standard of care, but challenges remain in obtaining clear resection margins. The current study evaluated the feasibility of endoscopic fluorescence-guided surgery (FGS) to improve surgical resection in a human sinus surgical model. Methods: A fluorescence endoscope optimized for near-infrared (NIR) fluorescence detection was evaluated in a phantom study. Various endoscope diameters (4 and 10 mm) and viewing angles (0, 30, and 45 degrees) were evaluated to determine the sensitivity of the system for IRDye800CW detection at various working distances (1-5 cm). Endoscopic FGS was then validated in a three-dimensional human sinus surgical model to which squamous cell tumors derived from mice were inserted. Mice had received intravenous panitumumab-IRDye800CW and upon fluorescence-guided tumor resection, mean fluorescence intensity (MFI) and tumor-to-background ratio (TBR) were calculated in in situ and ex vivo settings. Results: A significantly higher fluorescence intensity was found when using the 10-mm diameter endoscope compared to the 4mm diameter endoscope (P < .001). No significant difference in MFI was found among the viewing angles of the 4-mm diameter endoscope. Using the human sinus model, the highest MFI and TBR were obtained at a 1-cm working distance compared to longer working distances. Conclusion: We demonstrate that clinically acceptable TBRs were obtained with several working distances to discriminate tumor tissue from adjacent normal tissue in a human sinus model, and that endoscopic FGS may have great potential in identifying residual tumor tissue regions during surgery.

Clinical imaging performance using a fluorescent antibody was compared across 3 cancers to elucidate physical and biologic factors contributing to differential translation of epidermal growth factor receptor (EGFR) expression to macroscopic fluorescence in tumors. Methods: Thirty-one patients with high-grade glioma (HGG, n 5 5), head-and-neck squamous cell carcinoma (HNSCC, n 5 23), or lung adenocarcinoma (LAC, n 5 3) were systemically infused with 50 mg of panitumumab-IRDye800 1-3 d before surgery. Intraoperative open-field fluorescent images of the surgical field were acquired, with imaging device settings and operating room lighting conditions being tested on tissue-mimicking phantoms. Fluorescence contrast and margin size were measured on resected specimen surfaces. Antibody distribution and EGFR immunoreactivity were characterized in macroscopic and microscopic histologic structures. The integrity of the blood-brain barrier was examined via tight junction protein (Claudin-5) expression with immunohistochemistry.Stepwise multivariate linear regression of biologic variables was performed to identify independent predictors of panitumumab-IRDye800 concentration in tissue. Results: Optimally acquired at the lowest gain for tumor detection with ambient light, intraoperative fluorescence imaging enhanced tissue-size dependent tumor contrast by 5.2-fold, 3.4-fold, and 1.4-fold in HGG, HNSCC, and LAC, respectively. Tissue surface fluorescence target-to-background ratio correlated with margin size and identified 78%-97% of at-risk resection margins ex vivo. In 4-mm-thick tissue sections, fluorescence detected tumor with 0.85-0.89 areas under the receiver-operating-characteristic curves. Preferential breakdown of blood-brain barrier in HGG improved tumor specificity of intratumoral antibody distribution relative to that of EGFR (96% vs. 80%) despite its reduced concentration (3.9 ng/mg of tissue) compared with HNSCC (8.1 ng/mg) and LAC (6.3 ng/mg). Cellular EGFR expression, tumor cell density, plasma antibody concentration, and delivery barrier were independently associated with local intratumoral panitumumab-IRDye800 concentration, with 0.62 goodness of fit of prediction. Conclusion: In multicancer clinical imaging of a receptor-ligand-based molecular probe, plasma antibody concentration, delivery barrier, and intratumoral EGFR expression driven by cellular biomarker expression and tumor cell density led to heterogeneous intratumoral antibody accumulation and spatial distribution whereas tumor size, resection margin, and intraoperative imaging settings substantially influenced macroscopic tumor contrast.

Background As receptor-ligand based strategies emerge for surgical imaging, the relative importance of receptor expression in different tumor types is unknown. Near-infrared (NIR) labeled epidermal growth factor receptor (EGFR) antibody, panitumumab-IRDye800, was evaluated across three cancers to demonstrate its clinical utilities and a holistic analysis framework. Methods Thirty-one patients diagnosed with high-grade glioma (HGG, n=5, NCT03510208), head and neck squamous cell carcinoma (HNSCC, n=23, NCT02415881) or lung adenocarcinoma (LAC, n=3, NCT03582124) received systemic administration of 50 mg panitumumab-IRDye800 days prior to surgery. Intraoperative NIR laparoscopic or open-field images of the surgical field were acquired and tissue mimicking phantoms were constructed to identify optimal imaging conditions. Margin distance was correlated to fluorescence on resected specimen surface. Panitumumab-IRDye800 distribution was registered to histology in fixed tissue sections. Immunohistochemistry characterized EGFR expression. Results Intraoperative NIR imaging enhanced tumor contrast against surrounding healthy tissue by 5.2-fold, 3.4-fold and 1.4-fold in HGG, HNSCC and LAC, respectively. Imaging quality was optimal at the lowest gain possible under ambient light. Ex vivo NIR fluorescence identified 78-97% of at-risk resection margins, with 72-92% sensitivity and 67-96% specificity for tumor in fixed tissue sections. Intratumoral panitumumab-IRDye800 concentration correlated with total tumoral EGFR expression (HGG > HNSCC > LAC) and delivery barrier. Cellular EGFR expression (80%) and tumor cell density (3000 cells/mm2) was highest in HGG. Conclusions In multiple tumor types, EGFR-targeting in fluorescence-guided surgery translated to enhanced macroscopic tumor contrast and successful margin assessment despite disparate tumor cell density and heterogeneous delivery of pantimumab-IRDye800.