Treatment of pulmonary nodule: from VATS to RATS.

Background: The incidental detection of solitary pulmonary nodule (SPN) is currently increasing due to the widespread use of computed tomography (CT) during the follow up in oncological patients or in screening trials. A quick and definitive histological diagnosis of these nodes is mandatory as, in case of primitive lung cancer, an early detection could improve both surgical results and prognosis. The minimally invasive pulmonary resection (MIPR) is the gold standard procedure for diagnosis and treatment of small lung nodules, but it can be difficult to localize deep nonpalpable nodes that lie in the lung parenchyma. Hence, throughout the years several techniques have been developed to better localize deep or sub solid nodes. We describe our experience with radio-guided technique.

Methods: Patients with SPN smaller than 10 mm and/or with a distance from the visceral pleura equal or larger than 10 mm underwent MIPR after CT injection of a solution containing 0.2 mL Tc-labelled human serum albumin microspheres and 0.1 mL of non-ionic contrast. During surgical procedures, a collimated probe, connected to a gamma-ray detector, was used to scan the lung and detect the target area. The area of major radioactivity was then resected.

Results: Between 2010 and 2015, 175 patients (M/F: 97/78) underwent minimally invasive resection (thoracoscopic or robotic) with radio-guided technique. The mean node diameter was 13 mm (range, 5-20 mm), and the mean distance from the visceral pleura was 15 mm (range, 6-39 mm). No significant CT-guided-injection-related complications occurred, except for 13 patients (7.4%) who developed a pneumothorax (PNX) not requiring chest tube insertion. This technique guaranteed a successfully intra-operative node localization in 100% of cases. The mean duration of the surgical procedure was 44 min (range, 25-130 min). The mean length of pleural drainage and mean hospital stay was 2.6 days (range, 1-5 days) and 3.9 days (range, 1-7 days) respectively. No mortality or perioperative complications occurred. Pathology reports showed 105 metastases, 55 primitive lung cancers and 15 benign lesions. In case of suspicion of primitive lung tumour an intraoperative frozen exam was conducted, and all patients underwent lobectomy or segmentectomy with lymphadenectomy [41 patients with thoracotomy, 11 with robotic surgery and 3 with video-assisted thoracoscopic surgery (VATS)].

Conclusions: Our experience confirms that radio-guided thoracoscopic surgery (RGTS) is a feasible and safe procedure, thanks to its high success rate the radio-guided technique is helpful to overcome the lack of tactile feedback during MIPR [VATS and robotic-assisted thoracoscopic surgery (RATS)] and to limit conversion to open surgery.