Near-Infrared Imaging with Indocyanine Green for Detection of Endometriosis Lesions (Gre-Endo Trial): A Pilot Study

Study Objective: To evaluate near-infrared radiation imaging with intravenous indocyanine green (NIR-ICG) during laparoscopic intervention to identify endometriosis lesions. Design: A single-center, prospective, single-arm pilot study (Canadian Task Force classification II-2). Setting: An academic tertiary care and research center. Patients: Twenty-seven patients with symptomatic endometriosis were enrolled. Interventions: Patients underwent laparoscopic surgery using a laparoscopic system prototype with NIR-ICG. Measurements and Main Results: A total of 116 suspected endometriosis lesions were removed from 27 patients. One hundred lesions had already been visualized in white light imaging by an expert surgeon; the remaining 16 were detected and removed using NIR-ICG. A total of 111 specimens were positive for endometriosis pathology. Positive predictive value of 95% and 97.8% and negative predictive value of 86.2% and 82.3% were found by white light imaging and NIR-ICG, respectively, with sensitivity of 85.6% and 82% and specificity of 95.2% and 97.9%, respectively. Conclusion: NIR-ICG may be a tool for intraoperative diagnosis, confirmation of visible endometriosis lesions, and a marker for identifying occult endometriosis. Further prospective studies with a larger population sample are warranted to validate these encouraging preliminary results.