A novel surgical marking system for small peripheral lung nodules based on radio frequency identification technology: Feasibility study in a canine model

ObjectiveWe investigated the feasibility and accuracy of a novel surgical marking system based on radiofrequency identification (RFID) technology for the localization of small peripheral lung nodules (SPLNs) in a canine model.MethodsThe system consists of 4 components: (1) micro RFID tags (13.56 MHz, 1.0 × 1.0 × 0.8 mm), (2) a tag delivery system with a bronchoscope, (3) a wand-shaped locating probe (10-mm diameter), and (4) a signal processing unit with audio interface. Before the operation, pseudolesions mimicking SPLNs were prepared in 7 dogs by injecting colored collagen. By use of a computed tomographic (CT) guide, an RFID tag was placed via a bronchoscope close to each target lesion. This was then followed by scanning with the locating probe, and wedge resection was performed when possible. Operators can locate the tag by following the sound emitted by the system, which exhibits tone changes according to the tag-probe distance. The primary outcome measure was the rate of wedge resection with good margins.ResultsA total of 10 pseudolesions imitating SPLNs were selected as targets. During thoracoscopic procedures, 9 of 10 tags were detected by the system within a median of 27 seconds. Wedge resections were performed for these 9 lesions with a median margin of 11 mm. The single failure was caused by tag dislocation to the central airway.ConclusionsSuccessful localization and wedge resection of pseudolesions with appropriate margins were accomplished in an experimental setting. Our RFID marking system has future applications for accurately locating SPLNs in a clinical setting.