Feasibility Of Confocal Laser Endomicroscopy Research Articles

Optical biopsy of penile cancer with in vivo confocal laser endomicroscopy

IntroductionSurgical management of penile cancer depends on accurate margin assessment and staging. Advanced optical imaging technologies may improve penile biopsy and organ-sparing treatment. We evaluated the feasibility of confocal laser endomicroscopy for intraoperative assessment of benign and malignant penile tissue. Patients and methodsWith institutional review board approval, 11 patients were recruited, 9 with suspected penile cancer, and 2 healthy controls. Confocal laser endomicroscopy using a 2.6-mm fiber-optic probe was performed at 1 or 2 procedures on all subjects, for 13 imaging procedures. Fluorescein was administered intravenously approximately 3 minutes prior to imaging for contrast. Video sequences from in vivo (n = 12) and ex vivo (n = 6) imaging were obtained of normal glans, suspicious lesions, and surgical margins. Images were processed, annotated, characterized, and correlated with standard hematoxylin and eosin histopathology. ResultsNo adverse events related to imaging were reported. Distinguishing features of benign and malignant penile tissue could be identified by confocal laser endomicroscopy. Normal skin had cells of uniform size and shape, with distinct cytoplasmic membranes consistent with squamous epithelium. Malignant lesions were characterized by disorganized, crowded cells of various size and shape, lack of distinct cytoplasmic membranes, and hazy, moth-eaten appearance. The transition from normal to abnormal squamous epithelium could be identified. ConclusionsWe report the initial feasibility of intraoperative confocal laser endomicroscopy for penile cancer optical biopsy. Pending further evaluation, confocal laser endomicroscopy could serve as an adjunct or replacement to conventional frozen section pathology for management of penile cancer.

Assessing the feasibility of confocal laser endomicroscopy in solitary pulmonary nodules for different part of the lungs, using either 0.6 or 1.4 mm probes.

BackgroundMalignant solitary pulmonary nodules (SPN) have become more prevalent, with upper lobes predilection. Probe-based confocal laser endomicroscopy (pCLE) provides in-vivo imaging of SPN. However, the stiffness of the 1mm confocal probe (AlveoFlex) causes difficult accessibility to the upper lobes. A thinner 600μm probe designed for bile duct exploration (CholangioFlex) has the potential to reach the upper lobes.ObjectivesTo examine the accessibility of malignant SPNs in all segments of the lungs using either the 0.6mm or 1.4 mm probe and to assess the quality and inter observer interpretation of SPN confocal imaging obtained from either miniprobes.MethodsRadial(r)-EBUS was used to locate and sample the SPN. In-vivo pCLE analysis of the SPN was performed using either CholangioFlex (apical and posterior segments of the upper lobes) or AlveoFlex (other segments) introduced into the guide sheath before sampling. pCLE features were compared between the two probes.ResultsFourty-eight patients with malignant SPN were included (NCT01931579). The diagnostic accuracy for lung cancer using r-EBUS coupled with pCLE imaging was 79.2%. All the SPNs were successfully explored with either one of the probes (19 and 29 subjects for CholangioFlex and AlveoFlex, respectively). A specific solid pattern in the SPN was found in 30 pCLE explorations. Comparison between the two probes found no differences in the axial fibers thickness, cell size and specific solid pattern in the nodules. Extra-alveolar microvessel size appeared larger using CholangioFlex suggesting less compression effect. The kappa test for interobserver agreement for the identification of solid pattern was 0.74 (p = 0.001).ConclusionThis study demonstrates that pCLE imaging of SPNs is achievable in all segments of both lungs using either the 0.6mm or 1.4mm miniprobe.

Intraoperative Optical Biopsy during Robotic Assisted Radical Prostatectomy Using Confocal Endomicroscopy

Intraoperative optical biopsy technologies may aid in the identification of important anatomical landmarks and improve surgical outcomes of robotic assisted radical prostatectomy. We evaluate the feasibility of confocal laser endomicroscopy during robotic assisted radical prostatectomy. A total of 21 patients with biopsy proven prostate cancer scheduled for robotic assisted radical prostatectomy were recruited. After intravenous administration of fluorescein 15 patients underwent invivo intraoperative confocal laser endomicroscopy of prostatic and periprostatic structures using a 2.6 or 0.85 mm imaging probe. Standard robotic instruments were used to grasp and maneuver the confocal laser endomicroscopy probes for image acquisition. Confocal laser endomicroscopy imaging was performed exvivo on fresh prostate specimens from 20 patients. Confocal video sequences acquired invivo and exvivo were reviewed and analyzed, with additional image processing using a mosaicing algorithm. Processed confocal images were compared with standard hematoxylin and eosin analysis of imaged regions. Confocal laser endomicroscopy was successfully integrated with robotic surgery, including co-registration of confocal video sequences with white light and probe handling with standard robotic instrumentation. Intraoperative confocal laser endomicroscopy imaging of the neurovascular bundle before and after nerve sparing dissection revealed characteristic features including dynamic vascular flow and intact axon fibers. Exvivo confocal imaging of the prostatic parenchyma demonstrated normal prostate glands, stroma and prostatic carcinoma. We report the initial feasibility of optical biopsy of prostatic and periprostatic tissue during robotic assisted radical prostatectomy. Image guidance and tissue interrogation using confocal laser endomicroscopy offer a new intraoperative imaging method that has the potential to improve the functional and oncologic outcomes of prostate cancer surgery.

In vivomolecular imaging of HER2 expression in a rat model of Barrett's esophagus adenocarcinoma

Human epidermal growth factor receptor 2 (HER2) is involved in the malignant progression of several human cancers, including esophageal adenocarcinoma (EAC). The purpose of this study was to evaluate HER2 overexpression and to explore the feasibility of confocal laser endomicroscopy for in vivo molecular imaging of HER2 status in an animal model of Barrett's-related EAC. Rats underwent esophagojejunostomy with gastric preservation. At 30 weeks post-surgery, the esophagus of 46 rats was studied; endoscopic and histological findings were correlated with HER2 immunofluorescence on excised biopsies and gross specimens. At this age, 23/46 rats developed Barrett's esophagus (BE), and 6/46 had cancer (four EAC and two squamous cell carcinomas). A significant overexpression of HER2 was observed in esophageal adenocarcinoma compared with normal squamous esophagus (9.4-fold) and BE (6.0-fold). AKT and its phosphorylated form were also overexpressed in cancer areas. Molecular imaging was performed at 80 weeks post-surgery in four rats after tail injection of fluorescent-labeled anti-HER2 antibody. At this age, 3/4 rats developed advance adenocarcinoma and showed in vivo overexpression of HER2 by molecular confocal laser endomicroscopy with heterogeneous distribution within cancer; no HER2 signal was observed in normal or Barrett's tissues. Therefore, HER2 overexpression is a typical feature of the surgical induced model of EAC that can be easily quantified in vivo using an innovative mini-invasive approach including confocal endomicroscopy; this approach may avoid limits of histological evaluation of HER2 status on 'blinded' biopsies.

Confocal Laser Endomicroscopy of Bladder Tumors Associated With Photodynamic Diagnosis: An Ex Vivo Pilot Study

To improve the sensitivity of white light cystoscopy, photodynamic diagnosis (PDD) is useful but has low specificity. Recently, confocal laser endomicroscopy (CLE) has been used for the diagnosis of urothelial cell carcinoma. The main objective was to examine the feasibility of simultaneous PDD and CLE. A secondary objective was to determine whether hexyl aminolevulinic acid (HAL) can be used just as fluorescein for CLE. In the present prospective single-center study with a same-patient comparison, patients with suspected urothelial cell carcinoma underwent surgical exploration after receiving a bladder instillation of HAL. After resection of suspected lesions under blue light, the samples were inspected ex vivo using CLE with and without fluorescein. Simultaneous blue light CLE inspection was performed. All samples were then transferred to the pathology laboratory for the classic analysis. Of the 12 patients studied, blue light cystoscopy revealed suspect lesions in 11; 10 had pathology proven urothelial cell carcinoma. CLE analysis was not modified by sample exposure to blue light, which facilitated orientation of the fiber toward the suspect red fluorescence areas. The fluorescence obtained with HAL-CLE was insufficient for microscopic histologic analysis, unlike the resolution obtained with fluorescein. Comparing CLE and the pathologic findings was possible and conclusive for 4 of 12 samples. Combining PDD and CLE ex vivo demonstrated the usefulness of HAL for guiding blue light CLE. HAL was insufficient to allow histologic CLE, which required the use of fluorescein. The results of this pilot study have indicated the feasibility of CLE. However, an in vivo method incorporating fluorescein and PDD will be required to improve the diagnostic specificity of PDD alone.