Why use fiducial markers?

Fiducial markers are small, radiopaque implants, typically gold, placed in or near the target volume to enhance the accuracy of image-guided radiotherapy (IGRT). They provide consistent reference points on imaging, enabling precise tumor localization and motion management, which is essential for delivering high-dose treatments while minimizing exposure to surrounding healthy tissue. Using fiducial markers for radiotherapy treatments have proven to not only improve treatment outcomes in terms of reduced side effects but also in terms of tumor control.

precision with fiducial markers

Increased Accuracy

98% CTV dose coverage was achieved using fiducial markers, comparable to using MR-Linac. When using CBCT without fiducial markers CTV dose coverage was 62%1.

Reduced side effects

50% reduction in acute grade ≥2 GU toxicity has been observed when reducing PTV margins from 4 mm to 2 mm for prostate SBRT2. Real-time tracking with fiducial markers may enable the use of such margins3.

Improved treatment outcome

97% biochemical control at 3 years in high-risk patients when positioned using fiducial markers  vs. 78% without IGRT4.  

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  1. Nicosia L, et al. Acta Oncol. 2021;60(2):215–22. https://doi.org/10.1080/0284186X.2020.1821090

  2. Neylon J, et al. Int J Radiat Oncol Biol Phys. 2024;118(5):1181–91. https://doi.org/10.1016/j.ijrobp.2023.12.035

  3. Ghadjar P, et al. Radiother Oncol. 2019;141:5–13. https://doi.org/10.1016/j.radonc.2019.08.027

  4. Zelefsky MJ, et al. Int J Radiat Oncol Biol Phys. 2012;84(1):125–9. https://doi.org/10.1016/j.ijrobp.2011.11.047

Watch this 7-minute video to better understand the critical role fiducial markers play in achieving greater precision during radiation therapy.