Thoracoscopy Combined with Autofluorescence Imaging and Narrow Band Imaging for the Diagnosis of Malignant Pleural Mesothelioma

Abstract

Background and Objective. Thoracoscopy is an essential procedure for the definitive diagnosis of malignant pleural mesothelioma(MPM). However, in some cases of early-stage MPM, it is difficult to detect a lesion even through conventional thoracoscopy. In the present study, to improve the diagnostic accuracy of thoracoscopy on MPM, autofluorescence imaging(AFI) and a narrow band imaging(NBI) system were assessed in combination with the conventional method. Subjects and Methods. Thoracoscopy combined with AFI and NBI was performed on 12 patients with pleural fluid retention, suspected of MPM. Thoracoscopy under local anesthesia and video-assisted thoracoscopic surgery(VATS) were performed on 7 and 5 patients, respectively. Examination was carried out using a flexible bronchoscope(Olympus BF-F260) for AFI and a conventional white light thoracoscope(Olympus LTF-240) for NBI. Results. In 7 of 12 patients, a diagnosis of MPM was made by pleural biopsy using thoracoscopy combined with AFI and NBI. Autofluorescence thoracoscopy showed that nodules suspicious for mesothelioma were clearly visualized as magenta fluorescence, while the intact pleura appeared green in color. In the cases of MPM, thoracoscopy with NBI demonstrated emphasized irregularity of the pleura compared with findings on conventional white light thoracoscopy, and abnormal pink/white nodules with increased vessel growth were easily detected. Conclusion. Thoracoscopy combined with AFI and NBI is a novel tool for the diagnosis of MPM. There is a possibility that this procedure may make it possible to distinguish between pleural lesions due to MPM and the intact pleura more accurately.