Preoperative localization of solitary pulmonary nodule: a narrative review

Abstract

The diffusion of lung cancer screening programs using CT scan and the improvement in imaging technologies have led to an increased number of indeterminate solid and subsolid small lung lesions, in which percutaneous or bronchoscopic diagnostic procedures may be unsuccessful or not technically feasible. In these cases, a surgical resection using minimally invasive techniques can be indicated, with both diagnostic and therapeutic purposes. Intraoperative detection of small lung nodules is still a challenge for surgeons, especially in the era of video and robot-assisted thoracic surgery, which could make direct finger palpation of lung parenchyma through thoracoscopic incisions demanding and thus require conversion to a standard thoracotomy to find the lesion. In this scenario, several preoperative and intraoperative localization techniques for small lung nodules are available, from image-guided techniques with percutaneous markers placement or injection of liquid agents (dyes, radio-tracers), to novel promising marking methods using electromagnetic navigation bronchoscopy (ENB) or Hybrid Room technology. The proper localization technique should be selected according to the lesion's position, size, and radiological characteristics, as well as the expertise and the preferences of the staff performing preoperative and surgical procedures. The aim of this narrative review is to describe and compare various available preoperative and intraoperative localization techniques in terms of safety, possible complications, cost/effectiveness and feasibility in everyday clinical practice, and to provide information on this topic for clinicians dealing with non-palpable or deep-located small lung nodules.