Intraoperative imaging and localization techniques for part-solid nodules

Abstract

With the implementation of guidelines for low-dose computed tomography (CT) scans for high-risk patients starting in 2011, combined with the overall increased use of computed axial imaging, solitary nodules are being detected more frequently, with a prevalence of up to 24% in high-risk smokers. In appropriate patients, part-solid lesions with a solid component greater than 8 mm, as well as lesions with evidence of growth on serial CT scans, are high risk for metastases if left untreated and should be considered for excision for both diagnosis and treatment. inimally invasive wedge resection may often be the modality of choice to diagnose and treat small nodules, especially when nonsurgical CT-guided percutaneous or bronchoscopic biopsy is unattainable, nondiagnostic, or inconclusive in the high-risk setting. However, subcentimeter nodules and ground-glass opacities (GGOs) can be difficult to identify or discern with visual inspection or indirect instrument-based palpation alone, especially in the era of video-assisted thoracic surgery (VATS) and robotic lung resection. Often in this setting, preoperative and intraoperative tumor marking techniques may provide significant aid to the surgeon and decrease time in the operating room and potential morbidity in patients undergoing these procedures. With the availability of hybrid operating rooms, many of these localization techniques may be performed by the surgeon at the time of the operation and not as a separate procedure. Additionally, new radiologic and technical advancements in the last decade have expanded the number of intraoperative localization techniques that may be more widely available to the majority of practicing thoracic surgeons. Finally, emerging new modalities may combine molecular-guided localization and image-based diagnosis of pulmonary malignancies. This article will review the more common localization techniques (other than direct palpation or visualization), as well as discuss emerging image-dependent technologies.