Introduction to Advanced Particle Therapy Localization

Endovascular fiducial marker placement (EVFM) has emerged as a robust alternative for image-guided particle therapy. This technique is particularly vital for proton and carbon-ion radiotherapy. These advanced therapies require precise tumor tracking to minimize radiation exposure to surrounding healthy tissues. Unlike traditional methods, EVFM utilizes the pulmonary arterial system to position markers near the lesion.

Efficacy and Safety of Endovascular Fiducial Marker Placement

A recent study evaluated the safety and feasibility of placing platinum coil markers via the endovascular route. Researchers utilized a 5F catheter system through the right femoral vein. They successfully placed markers in the distal pulmonary arteries of 54 patients. Notably, the cohort included those with both primary and metastatic lung tumors. The results demonstrated that the endovascular fiducial marker placement technique resulted in a median tumor-to-marker distance of only 5 mm. This proximity is critical for ensuring the accuracy of high-dose particle beams.

Procedural Outcomes and Minimal Complications

Clinicians observed no significant complications related to the placement of these markers. Furthermore, transient arrhythmias only occurred when the guide wire passed through the right ventricle. These episodes were self-limiting and did not affect the procedure's success. More importantly, migration during the course of irradiation was almost non-existent. Specifically, the median migration was 0 mm. Consequently, every patient in the study completed their scheduled particle therapy without interruption. Therefore, this method offers a safer profile compared to transthoracic approaches, which often carry a higher risk of pneumothorax.

Comparing Localization Techniques

While bronchoscopy-guided or CT-guided placements are common, EVFM respects the lung's anatomy. It avoids pleural puncture entirely. This procedural advantage reduces the risk of iatrogenic lung collapse. Additionally, the endovascular approach remains feasible even for patients with compromised pulmonary function. In summary, this approach provides accurate localization and high procedural stability for lung cancer patients undergoing advanced radiotherapy.

Frequently Asked Questions

Why is endovascular fiducial marker placement preferred over percutaneous methods?

Endovascular placement significantly reduces the risk of pneumothorax because it does not involve piercing the pleura. This makes it a safer option for patients with underlying respiratory conditions.

How stable are these markers during the radiation treatment period?

Research indicates that these markers exhibit minimal to zero migration. Their placement within the subsegmental pulmonary artery branches ensures they remain fixed relative to the tumor throughout the therapy course.

Is the procedure suitable for all types of lung tumors?

Yes, the technique is effective for both primary and metastatic lung tumors located in various lobes, provided there is a reachable pulmonary artery branch near the lesion.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

1. Terashima K et al. Endovascular pulmonary arterial fiducial marker placement for particle radiotherapy using proton or carbon-ion beams for lung cancer. J Radiat Res. 2026 Apr 23. doi: undefined. PMID: 42024421.

2. Baker S et al. Endovascular Coils as Lung Tumor Fiducial Markers for Real-Time Tumor Tracking in Stereotactic Body Radiotherapy: Comparison of Complication Rates with Transthoracic Fiducial Marker Placement. J Vasc Interv Radiol. 2019 Dec;30(12):1916-1923.

3. Therasse E et al. Safety and Efficacy of Endovascular Fiducial Marker Insertion for CyberKnife Stereotactic Radiation Therapy Planning in Early-Stage Lung Cancer. J Vasc Interv Radiol. 2017 Aug;28(8):1140-1146.