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Fiducial Placement

Fiducial next to penny

These small gold seeds called fiducials are implanted near a soft tissue tumor to act as a marker to define the lesion(s) position with sub-millimeter precision. They are usually not necessary for brain or spine lesions.

If fiducial placement is required, keep in mind the following:

  • Some medications such as aspirin, ibuprofen or Plavix will need to be held for one week prior. Others should be held for only 48 hours prior to the exam. Be sure to review all prescribed and over-the-counter medications with the CyberKnife nurse prior to your exam date.
  • In most scenarios, fiducial placement is done as an outpatient service in the Radiology Department and you are able to return home in 4 to 8 hours.
  • The physicians will prescribe the best fiducial placement for you and the CyberKnife center staff will make all the arrangements.
  • Depending on the exact fiducial placement procedure used, the patient may not be able to eat or drink for up to 6-12 hours prior to the fiducial placement procedure.
  • A designated driver will be needed to drive the patient home.
  • There may be slight discomfort after the procedure

Fiducial placement is potentially required about one week prior to treatment for the following conditions:

Head and neck and soft tissue lesions
Typically anesthesia is required to place 3-6 fiducials by a surgeon or percutaneously by a radiologist under CT guidance.

Lung lesions
CT- guided lung fiducials may result in a complication known as pneumothorax – air trapped in the space between the lung and the chest wall – also referred to as “collapsed lung”. This complication occurs in about 1/3 of the patients. If a pneumothorax occurs, it may be minor, requiring no further treatment, or it may require a chest tube to remove this air pocket and re-expand the lung, potentially resulting in admission to the hospital overnight. Other fiducial placement methods such as placing them through a scope that passes through the bronchus or esophagus may be used.

Liver, pancreatic, retroperitoneal and kidney lesions
Placement in these instances is usually done under CT guidance in the Radiology Department or if surgical exploration is done, then fiducial placement may be done by the surgeon directly.

Prostate cancer
Prostate fiducials will typically be placed under ultrasound guidance, either by the urologist or by the radiation oncologist.

Spine lesions
Your physician will prescribe whether the small screws are necessary to mark the condition. Not all spine lesions require them.

Your pre-treatment set up and imaging will follow the above fiducial placement about one week after fiducial placement to allow the fiducials to settle into a stable position. If spinal fiducials are used, then treatment planning and your scheduled treatment days may occur sooner. You will be contacted throughout the steps in the process to schedule your appointment dates and times.