La chirurgie carcinologique guidée par la fluorescence proche infrarouge : optimisation du marquage tumoral

The goal of tumor surgery is the complete removal of the primary tumor with sufficient safety margins. Obtaining negative margins is essential for complete healing and it also reduces the risk of developing metastases. Currently, tumor limits are established by visual inspection, palpation and extemporaneous histological evaluation. Nevertheless, this has the disadvantage of being time-consuming and sometimes inaccurate. Fluorescence-guided surgery seems to provide answers to this problem of tumor delimitation with the disadvantage of a lack of specificity for the tumor tissue of the most used marker (indocyanine green, ICG). Moreover, different camera systems exist to guide these surgeries and it seems important to explore their capabilities before introducing them in the clinic.The main objective of this project was to optimize tumor labeling in the context of near- infrared fluorescence guided surgery.For this purpose, we coupled ICG with aptamers (E8 and V8) in order to specifically target tumor cells. Two cell lines were studied: FaDu cells from pharyngeal squamous cell carcinomas and U87 cells from human glioblastomas. The FaDu cells were chosen as a positive model because they present the targets of the E8 and V8 aptamers while the U87 cells were the negative model. These 2 cell types have the ability to associate in homogeneous cell clusters thus constituting a very interesting diffusion model. First results suggesting a specific labeling were obtained by microscopy and flow cytometry. In order to increase the amount of ICG bound to aptamers, ICG aggregates were formed and bound to aptamers.Furthermore, we propose a simple, reproducible and innovative model reproducing the microinvasion by tumor cells in the periphery of the primary tumor. It is a model made of spheroids included in a phantom reproducing the optical properties of tissues.L'objectif des chirurgies d'exérèse tumorale est l'ablation complète de la tumeur primitive avec des marges de sécurité suffisantes. L'obtention de marges négatives est indispensable à la guérison complète et diminue également le risque de développement de métastases. Actuellement, les limites tumorales sont établies par une inspection visuelle, une palpation ainsi qu'une évaluation histologique extemporanée. Néanmoins, cela présente l'inconvénient d'être chronophage et parfois inexact. La chirurgie guidée par la fluorescence semble apporter des réponses à ce problème de délimitation tumorale avec cependant l'inconvénient d'un manque de spécificité pour le tissu tumoral du marqueur le plus utilisé (le vert d'indocyanine, ICG). De plus, différents systèmes de caméras existent pour guider ces chirurgies et il semble important de pouvoir en explorer les capacités avant de les introduire en clinique.L'objectif principal de ce projet était d'optimiser le marquage tumoral dans le cadre de chirurgie guidée par la fluorescence proche infrarouge.Pour cela nous avons coupler l'ICG avec des aptamères (E8 et V8) de façon à cibler spécifiquement les cellules tumorales. De premiers résultats semblant indiquer un marquage spécifique ont pu être obtenu en microscopie ainsi qu'en cytométrie en flux. De façon à augmenter la quantité d'ICG liée aux aptamères, des agrégats d'ICG ont été formés et liés aux aptamères. De plus, nous proposons un modèle simple, reproductible et innovant reproduisant le micro-envahissement par les cellules tumorales en périphérie de la tumeur primitive. Il s'agit d'un modèle constitué de sphéroïdes inclus dans un fantôme reproduisant les propriétés optiques des tissus

Near-Infrared Fluorescence-guided surgery : optimization of tumor marking

L'objectif des chirurgies d'exérèse tumorale est l'ablation complète de la tumeur primitive avec des marges de sécurité suffisantes. L'obtention de marges négatives est indispensable à la guérison complète et diminue également le risque de développement de métastases. Actuellement, les limites tumorales sont établies par une inspection visuelle, une palpation ainsi qu'une évaluation histologique extemporanée. Néanmoins, cela présente l'inconvénient d'être chronophage et parfois inexact. La chirurgie guidée par la fluorescence semble apporter des réponses à ce problème de délimitation tumorale avec cependant l'inconvénient d'un manque de spécificité pour le tissu tumoral du marqueur le plus utilisé (le vert d'indocyanine, ICG). De plus, différents systèmes de caméras existent pour guider ces chirurgies et il semble important de pouvoir en explorer les capacités avant de les introduire en clinique.L'objectif principal de ce projet était d'optimiser le marquage tumoral dans le cadre de chirurgie guidée par la fluorescence proche infrarouge.Pour cela nous avons coupler l'ICG avec des aptamères (E8 et V8) de façon à cibler spécifiquement les cellules tumorales. De premiers résultats semblant indiquer un marquage spécifique ont pu être obtenu en microscopie ainsi qu'en cytométrie en flux. De façon à augmenter la quantité d'ICG liée aux aptamères, des agrégats d'ICG ont été formés et liés aux aptamères. De plus, nous proposons un modèle simple, reproductible et innovant reproduisant le micro-envahissement par les cellules tumorales en périphérie de la tumeur primitive. Il s'agit d'un modèle constitué de sphéroïdes inclus dans un fantôme reproduisant les propriétés optiques des tissus.The goal of tumor surgery is the complete removal of the primary tumor with sufficient safety margins. Obtaining negative margins is essential for complete healing and it also reduces the risk of developing metastases. Currently, tumor limits are established by visual inspection, palpation and extemporaneous histological evaluation. Nevertheless, this has the disadvantage of being time-consuming and sometimes inaccurate. Fluorescence-guided surgery seems to provide answers to this problem of tumor delimitation with the disadvantage of a lack of specificity for the tumor tissue of the most used marker (indocyanine green, ICG). Moreover, different camera systems exist to guide these surgeries and it seems important to explore their capabilities before introducing them in the clinic.The main objective of this project was to optimize tumor labeling in the context of near- infrared fluorescence guided surgery.For this purpose, we coupled ICG with aptamers (E8 and V8) in order to specifically target tumor cells. Two cell lines were studied: FaDu cells from pharyngeal squamous cell carcinomas and U87 cells from human glioblastomas. The FaDu cells were chosen as a positive model because they present the targets of the E8 and V8 aptamers while the U87 cells were the negative model. These 2 cell types have the ability to associate in homogeneous cell clusters thus constituting a very interesting diffusion model. First results suggesting a specific labeling were obtained by microscopy and flow cytometry. In order to increase the amount of ICG bound to aptamers, ICG aggregates were formed and bound to aptamers.Furthermore, we propose a simple, reproducible and innovative model reproducing the microinvasion by tumor cells in the periphery of the primary tumor. It is a model made of spheroids included in a phantom reproducing the optical properties of tissues

La chirurgie carcinologique guidée par la fluorescence proche infrarouge : optimisation du marquage tumoral

The goal of tumor surgery is the complete removal of the primary tumor with sufficient safety margins. Obtaining negative margins is essential for complete healing and it also reduces the risk of developing metastases. Currently, tumor limits are established by visual inspection, palpation and extemporaneous histological evaluation. Nevertheless, this has the disadvantage of being time-consuming and sometimes inaccurate. Fluorescence-guided surgery seems to provide answers to this problem of tumor delimitation with the disadvantage of a lack of specificity for the tumor tissue of the most used marker (indocyanine green, ICG). Moreover, different camera systems exist to guide these surgeries and it seems important to explore their capabilities before introducing them in the clinic.The main objective of this project was to optimize tumor labeling in the context of near- infrared fluorescence guided surgery.For this purpose, we coupled ICG with aptamers (E8 and V8) in order to specifically target tumor cells. Two cell lines were studied: FaDu cells from pharyngeal squamous cell carcinomas and U87 cells from human glioblastomas. The FaDu cells were chosen as a positive model because they present the targets of the E8 and V8 aptamers while the U87 cells were the negative model. These 2 cell types have the ability to associate in homogeneous cell clusters thus constituting a very interesting diffusion model. First results suggesting a specific labeling were obtained by microscopy and flow cytometry. In order to increase the amount of ICG bound to aptamers, ICG aggregates were formed and bound to aptamers.Furthermore, we propose a simple, reproducible and innovative model reproducing the microinvasion by tumor cells in the periphery of the primary tumor. It is a model made of spheroids included in a phantom reproducing the optical properties of tissues.L'objectif des chirurgies d'exérèse tumorale est l'ablation complète de la tumeur primitive avec des marges de sécurité suffisantes. L'obtention de marges négatives est indispensable à la guérison complète et diminue également le risque de développement de métastases. Actuellement, les limites tumorales sont établies par une inspection visuelle, une palpation ainsi qu'une évaluation histologique extemporanée. Néanmoins, cela présente l'inconvénient d'être chronophage et parfois inexact. La chirurgie guidée par la fluorescence semble apporter des réponses à ce problème de délimitation tumorale avec cependant l'inconvénient d'un manque de spécificité pour le tissu tumoral du marqueur le plus utilisé (le vert d'indocyanine, ICG). De plus, différents systèmes de caméras existent pour guider ces chirurgies et il semble important de pouvoir en explorer les capacités avant de les introduire en clinique.L'objectif principal de ce projet était d'optimiser le marquage tumoral dans le cadre de chirurgie guidée par la fluorescence proche infrarouge.Pour cela nous avons coupler l'ICG avec des aptamères (E8 et V8) de façon à cibler spécifiquement les cellules tumorales. De premiers résultats semblant indiquer un marquage spécifique ont pu être obtenu en microscopie ainsi qu'en cytométrie en flux. De façon à augmenter la quantité d'ICG liée aux aptamères, des agrégats d'ICG ont été formés et liés aux aptamères. De plus, nous proposons un modèle simple, reproductible et innovant reproduisant le micro-envahissement par les cellules tumorales en périphérie de la tumeur primitive. Il s'agit d'un modèle constitué de sphéroïdes inclus dans un fantôme reproduisant les propriétés optiques des tissus

An Objective Structured Clinical Examination (OSCE) for French Dental Students: Feedback after 2 Years

The Objective Structured Clinical Examination (OSCE) is a practical examination that provides a standardized assessment of clinical competence. The aim of this study is to evaluate the objectivity and the reliability of an OSCE in dentistry. To this end, a retrospective monocentric observational study was conducted at the Faculty of Dentistry of Nancy by analyzing the exam results of 81 students. The study population consisted of the fifth-year students. The examination was broken down into six stations which were doubled, and different juries of examiners were constituted (installed in different rooms) according to the same composition. The p-value was set at 0.05. We found an equivalence of the results between the different rooms on the global mean score obtained at the six stations (p = 0.021). In terms of gender, women have statistically significantly higher overall scores than men (p = 0.001). The evaluation of a difference in the scores between full-time and part-time teachers does not find any statistically significant difference or equivalence in the station where it was possible to realize the comparison. However, the students’ waiting time before the exam seems to negatively influence the results. Compared with other international OSCE studies, the results presented seemed sufficiently objective and reliable, although some adjustments are still necessary

A Comparison of the Clinical and Radiological Extent of Denosumab (Xgeva®) Related Osteonecrosis of the Jaw: A Retrospective Study

Medication-related osteonecrosis of the jaw (MRONJ) is a severe side effect of antiresorptive medication. The aim of this study was to evaluate the incidence of denosumab-related osteonecrosis of the jaw and to compare the clinical and radiological extent of osteonecrosis. A retrospective study of patients who received Xgeva® at the Institut de Cancérologie de Lorraine (ICL) was performed. Patients for whom clinical and radiological (CBCT) data were available were divided into two groups: “exposed” for patients with bone exposure and “fistula” when only a fistula through which the bone could be probed was observed. The difference between clinical and radiological extent was assessed. The p-value was set at 0.05, and a total of 246 patients were included. The cumulative incidence of osteonecrosis was 0.9% at 6 months, 7% at 12 months, and 15% from 24 months. The clinical extent of MRONJ was significantly less than their radiological extent: in the “exposed” group, 17 areas (45%) were less extensive clinically than radiologically (p < 0.001) and respectively 6 (67%) for the “fistula” group (p < 0.031). It would seem that a CBCT is essential to know the real extent of MRONJ. Thus, it would seem interesting to systematically perform a CBCT during the diagnosis of MRONJ, exploring the entire affected dental arch

Validation of a Three-Dimensional Head and Neck Spheroid Model to Evaluate Cameras for NIR Fluorescence-Guided Cancer Surgery

Near-infrared (NIR) fluorescence-guided surgery is an innovative technique for the real-time visualization of resection margins. The aim of this study was to develop a head and neck multicellular tumor spheroid model and to explore the possibilities offered by it for the evaluation of cameras for NIR fluorescence-guided surgery protocols. FaDu spheroids were incubated with indocyanine green (ICG) and then included in a tissue-like phantom. To assess the capability of Fluobeam® NIR camera to detect ICG in tissues, FaDu spheroids exposed to ICG were embedded in 2, 5 or 8 mm of tissue-like phantom. The fluorescence signal was significantly higher between 2, 5 and 8 mm of depth for spheroids treated with more than 5 µg/mL ICG (p < 0.05). The fluorescence intensity positively correlated with the size of spheroids (p < 0.01), while the correlation with depth in the tissue-like phantom was strongly negative (p < 0.001). This multicellular spheroid model embedded in a tissue-like phantom seems to be a simple and reproducible in vitro tumor model, allowing a comparison of NIR cameras. The ideal configuration seems to be 450 μm FaDu spheroids incubated for 24 hours with 0.05 mg/ml of ICG, ensuring the best stability, toxicity, incorporation and signal intensity