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

Endobronchial coil spring fiducial markers for CyberKnife® stereotactic body radiation therapy

“…Other large retrospective series focusing on endobronchial FM placement in peripheral nodules 12,13 included a number of patients similar to our study. We observed a 50–70% lower migration rate compared to previously published conventional linear‐gold FM series (18–20%), 13–16 but a higher migration rate compared to cs‐FM airway deployment using ENB (<1%) 10,12 . Our data suggest that non‐linear FM should be preferred to the linear ones for PPL marking.…”

“…The reported rate of complications is low. Pneumothorax occurs in 0–6% of cases and is associated with guided transbronchial biopsies (TBB) performed before FM insertion 10–13 …”

“…The first reports of FM insertion guided by electromagnetic bronchoscopy (ENB) or radial‐endobronchial ultrasound (R‐EBUS) used linear‐gold FM. These are associated with a high migration rate, reaching 14–27% of the total number of inserted FM 14,15 and 18–20% of treated peripheral pulmonary lesions (PPL) 13,16 . Subsequently, non‐linear FM have been developed to reduce the migration rate.…”

Fiducial marker placement for stereotactic body radiation therapy via convex probe endobronchial ultrasound: a case series and review of literature

“…CyberKnife tracking depends on contrast differences between tumor and adjacent tissue. FMs are essential to aid accurate targeting, particularly when the lesion of interest is less than 20 mm in diameter or is adjacent to the heart or spine (34). Traditionally, FMs have been placed using a transthoracic CT-guided approach, a procedure with up to a 30-50% rate of pneumothorax rate when performed for this indication (27,(35)(36)(37)(38)(39).…”

“…While the two modalities have not been directly compared, the estimated rate of pneumothorax with CT-guided FM delivery versus RP-EBUS + ENB FM delivery is approximately 30% versus 6%, respectively (33,42). Notably, FMs delivered via either approach have not been shown to migrate out of position after placement over time (28,34,41,56).…”