NCI Dictionary of Cancer Terms

  • Resize font
  • Print
  • Email
  • Facebook
  • Twitter
  • Google+
  • Pinterest

The NCI Dictionary of Cancer Terms features 7,861 terms related to cancer and medicine.

Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.

fiducial marker
(fih-DOO-shul MAR-ker)
A medical device or small object placed in or on the body to mark an area for radiation treatment or surgery. For example, tiny gold seeds may be put into the prostate to mark a tumor before radiation therapy. This allows the doctor to give higher doses of radiation to the tumor with less harm to nearby healthy tissue.