Assessment of Per-Endoscopic Placement of Fiducial Gold Markers for Small Peripheral Lung Nodules < 20 mm Before Stereotactic Radiation Therapy

Abstract

Stereotactic radiotherapy is used to treat peripheral lung cancer in inoperable patients. Placement of fiducial gold markers (FMs) is crucial for tracking small lesions that are not visible on chest radiographs. Our objective was to assess endoscopic FM placement in small peripheral lung nodules (PLNs) that are not trackable using automated tracking software. All patients benefiting from virtual bronchoscopy and radial endobronchial ultrasonography (R-EBUS)-guided placement of FMs for PLNs< 20mm were included. After confirmation by biopsy sampling, a gold-seed FM was inserted into the nodule using a bronchial brush, without the use of fluoroscopy. The performance and complications of the procedure were recorded. From May 2010 to June 2015, FMs were placed in the PLNs of 54 consecutive patients, 34 of whom presented with a nodule< 20mm. Seventy-six percent of the procedures were performed using local anesthesia on an outpatient basis. The median long- and short-axis diameters of nodules were 15mm (9-20mm) and 11mm (6-20mm), respectively, with 31 of 34 nodules exhibiting a short axis of< 15mm. In 23 cases (79%), histologic samples were obtained during the procedure that allowed FM placement. Migration occurred in six cases, including two in the hours following the procedure. FMs were in place and visible on CT imaging performed 3months after radiation therapy in 80%of cases. No complications were reported. Diagnosis of peripheral nodules< 20mm and FM placement using R-EBUS are efficient and safe in a single procedure.