ABSTRACT
In 1895, W. C. Roentgen reported the discovery of invisible rays that were capable of passing through cardboard, paper, and other substances and could cast shadows of solid objects on lm. Roentgen also found that these rays (called x-rays, with “x” denoting an unknown quantity) could pass through human tissues, casting shadows of bones and metal objects. Soon aer the discovery of x-rays, radiation biologists began to experiment with the use of radiation to treat a variety of nonmalignant and malignant conditions. In 1900, or Stenbeck used radiation to treat a patient with skin cancer. Since that time, radiation has been used extensively for the treatment of cancer. e medical eld concerned with various aspects of using radiation to treat cancers is known as radiation oncology. Radiology, by contrast, has come to be used to describe the use of radiation for imaging rather than for treatment.
