a fiducial marker system using digital techniques

Coiled fiducials (Visicoil IBA Dosimetry, Memphis, TN) are flexible gold coil markers measuring 5–30 mm in length by 0.35–1.1 mm in diameter, and are deployed using a needle‐carrier delivery device that fits a 22‐gauge FNA needle. Newer fiducial designs aim to reduce fiducial migration. Traditional fiducials are cylindrical gold seeds measuring 3–5 mm in length by 0.75–1.2 mm in diameter, and are deployed using a 19‐gauge fine needle aspiration (FNA) needle.

Several types of fiducial markers and delivery systems exist. Given the ability of endoscopic ultrasound (EUS) to allow for close proximity to structures in the mediastinum, abdomen, and pelvis that may not otherwise be accessible by percutaneous approaches, the use of EUS‐guided fiducial placement into both luminal and extraluminal targets has become an accepted technique. Fiducials are inert radiographic markers which are implanted into the target lesion for this purpose. IGRT is dependent on reference points by which the target lesion can be identified and tracked. These techniques, such as stereotactic radiosurgery and intensity‐modulated RT, allow for the precise delivery of RT by being able to verify the target location and track its movement during the respiratory cycle. The development of real‐time image‐guided radiation therapy (IGRT) systems allows for the safe delivery of focal high‐dose RT to target lesions while minimizing the amount of collateral damage to normal tissue. Traditional radiation therapy (RT), involving the delivery of high doses of toxic radiation to a target field, is wrought with the unfortunate consequence of acute and chronic injury to healthy tissue adjacent to the tumor.

Icahn School of Medicine at Mount Sinai, New York, NY, USA Cheesman, Satish Nagula, and Christopher J. How to Place Fiducials for Radiation TherapyĪntonio R.

A fiducial marker system using digital techniques