Angelo Pierangelo1, David Fuks2, Abdelali Benali2, Pierre Validire2, Brice Gayet2. 1Ecole Polytechnique Paris, France, 2Institut Montsouris, Paris, France
Objective of the technology/device:
Characterization of peritoneal nodules is crucial to establish a precise evaluation of the cancer extension and to plan adequate therapy. Yet differentiating between inflammatory and malignant nodules may be challenging during laparoscopic assessment. Confocal Laser Endomicroscopy (CLE) is an emerging technique enabling real-time histology of living tissue. It has been used in a wide range of applications in gastrointestinal endoscopy, urology and pulmonary endoscopy procedures. Indeed, this study aimed at evaluating the accuracy of CLE for the characterization of peritoneal nodules.
Description of the technology and method of application:
Indocyanine Green was either administrated intravenously or applied topically on nodules in order to increase image contrast. Ex vivo CLE examination was performed immediately after resection of liver or peritoneal nodule. A 785nm wavelength laser unit and an ultra high definition (UHD) confocal miniprobe were used. The study was divided into two phases. In the first phase, all CLE recordings were openly evaluated by a pathologist expert in digestive cancer and an expert in CLE image interpretation, in comparison with histological results in order to define criteria of normal, inflammatory and malignant tissues. In the second phase, representative CLE sequences per specimen were randomized and blindly evaluated by a digestive surgeon. CLE accuracy for the diagnostic of benign, inflammatory and malignant nodule was calculated.
210 CLE recordings were acquired on 25 peritoneum specimens (6 benign, 11 inflammatory and 8 malignant) from 30 patients (mean age: 67, male gender: 15/30, mean recordings per specimen = 8,4). Excellent quality images were obtained with 785nm illumination wavelength and interpretation criteria to describe healthy, inflammatory and cancerous cancer could be defined. Overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy for the characterization of peritoneal metastasis were 75%, 100%, 100% and 89%respectively. Interobserver agreement was substantial (kappa 0.69).
This preliminary study enabled to define interpretation criteria for peritoneum and to validate them. CLE provides an important piece of additional information that correlate well with histopathology. Those performance results suggest that CLE is a very promising tool for the real-time characterization of peritoneum carcinomatosis nodules.