Laparoscopic narrow band imaging for detection of occult cancer metastases: a randomized feasibility trial

Selection of cancer treatment fundamentally relies on staging of the underlying malignancy. The aim of this study was to evaluate the feasibility and effectiveness of laparoscopic narrow band imaging (NBI) for operative staging and detection of occult peritoneal cancer metastases. A randomized, controlled feasibility trial with crossover design evaluating adult patients with gastrointestinal or gynecologic malignancies who have a clinical indication for diagnostic laparoscopy was conducted. Twenty-three patients were randomized to white-light followed by NBI laparoscopy (n = 11) or NBI followed by white-light laparoscopy (n = 12) using the Olympus Evis Exera II system. Three patients were excluded from analysis. In all 20 study patients, the abdominal cavity was sufficiently illuminated. An enhanced contrast of microvasculature and organ surface pattern was appreciated. Eight of the 20 patients (40 %) were found to have metastases of the peritoneal surface. While NBI did not show any additional peritoneal lesions, 2 of the 63 suspicious-appearing nodules seen on white-light imaging were not visible on NBI (p = 0.50). The median diameter of all the nodules identified was 2 mm (range 1-50 mm) and was identical with each method. The information from this feasibility study demonstrated that NBI provides adequate illumination of the abdominal cavity and a unique contrast that enhances microvasculature and architectural surface pattern. The results suggest that NBI laparoscopy is not superior in detecting peritoneal metastases compared to standard white-light laparoscopy, but might provide a technology that could be applied for other abdominal pathologies.