Using Visicoil MR Fiducial Markers for IGRT Fiducial Tracking



Abstract

Objectives: Tracking fiducial markers is a direct method of tumor localization in IGRT. The NEW Visicoil MR Platinum fiducial markers can be inserted using narrow needle (Gauges 19, 21 & 22) with less morbidity. We explored the feasibility of using Visicoil MR fiducial makers for IGRT.

Methods: The Visicoil MR Platinum fiducial markers used in this tested are:

  • 0.35 mm Diameter x 1.0 cm Length (22g Needle)
  • 0.50 mm Diameter x 0.5 cm Length (21g Needle)
  • 0.75 mm Diameter x 0.5 cm Length (19g Needle)

For Visicoil MR 0.35mm x 1.0 cm, the varied pitch of the very thin coil allows it to ‘fold up’ consistently into a ball shape when injected; which mitigates the possibility of fiducial migration. In our study, Visicoil MR 0.35 mm x 1.0 cm, Visicoil MR 0.50 mm x 0.5 cm, and Visicoil MR 0.75 mm x 0.5 cm were inserted into a phantom material along with two standard cylindrical gold fiducial markers (1.17 mm x 0.3 cm and 1.17 mm x 0.5 cm). The phantom was scanned by different MRI units (Siemens, GE and Philips) each using a variety of MRI sequences.

Results: All fiducial markers are clearly visible on MRI series. The fiducials were most clearly visible by a different pulse sequence for each MRI machine. All markers are clearly visible with CyberKnife kilo-voltage imaging devices. In our CyberKnife test, Visicoil MR fiducial markers were visible under default X-ray parameters. The precision of the lock-on is within 1 mm.

Conclusions: The Visicoil MR fiducial markers appear comparable with standard cylindrical gold fiducial markers for the purpose of CyberKnife tracking while being offered in much smaller gauge needles. Visicoil fiducial markers exhibit fewer artifacts on both CT and MRI. Their visibility on MRI scans should be optimized for different MRI manufacturers.

Related content

abstract
non-peer-reviewed

Using Visicoil MR Fiducial Markers for IGRT Fiducial Tracking


Author Information

Jing Feng Corresponding Author

Philadelphia Cyberknife, Philadelhia Cyberknife

Jun Yang

Radiation Oncology, JunXin Oncology, Guangzhou, CHN

Liang Xing

Philadelphia Cyberknife, Philadelphia CyberKnife

Andrew J. Cardin

Radiation Physics Solutions, LLC

Kevin Reynolds

Oncology, Iba/radiomed

Richard Brancaleone

Oncology, Iba/radiomed


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