Approaches for Lung Fiducial Markers Insertion in Stereotactic Body Radiotherapy: A Systematic Review and...

Pulmonary fiducial markers (FMs) allow real-time tracking for stereotactic body radiotherapy (SBRT) by CyberKnife, which is an alternative to surgery in early-stage inoperable non-small-cell lung cancer (NSCLC) or intrathoracic oligometastatic disease. We conducted a systematic review and meta-analysis to compare the clinical performance and safety of 3 available approaches for FMs insertion for peripheral pulmonary lesions (PPL): transthoracic, endovascular, and endobronchial accesses.

A systematic review with meta-analysis was performed by searching PubMed/MEDLINE and EMBASE databases for all articles on FM implantation before SBRT. Outcomes included clinical performance (inaccurate FM location and tracking rate) and per-procedural complications (pneumothorax and hemoptysis). We included 27 studies for a total of 2065 patients (627 with endobronchial access, 993 with transthoracic access, and 445 with endovascular access) and 4149 FMs insertions.

The lowest inaccurate FM location rate was found with nonlinear FM inserted by endobronchial access (0.030, 95% CI: 0.004-0.074). Tracking rate was high and similar with endobronchial (0.975, 95% CI: 0.949-0.994), endovascular (0.999, 95% CI: 0.941-1.000), and transthoracic approaches (0.985, 95% CI: 0.963-0.998). The highest rates of pneumothorax (0.342, 95% CI: 0.261-0.427) and hemoptysis (0.035, 95% CI: 0.015-0.060) occurred with the transthoracic access.

While nonlinear FM insertion through endobronchial access achieved the lowest rate of inaccurate FM location, all 3 implantation approaches demonstrated high tracking feasibility for SBRT delivered using the CyberKnife system.