NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,791 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.
- listen (eh-fuh-PROK-sih-rul)
- A substance being studied in the treatment of brain tumors and some other types of cancer. It increases the amount of oxygen in tumor tissues, which may make the tumor cells easier to kill with radiation therapy. Efaproxiral is a type of radiosensitizing agent. Also called RSR13.