Increased cure rates and decreased complications were soon documented. Supervoltage X rays became available with betatrons in the 1960s and linear accelerators in the late 1960s and 1970s. Again, improved control of local and regional disease occurred, as did further reductions in complications. This occurred primarily because the maximum energy deposition reached 4 cm in depth. Conformal radiation therapy was developed in the late 1980s and 1990s as a sophisticated attempt to confine more precisely the high doses of photon radiation to target tissues.
X rays can compliment surgery and medical oncology.
X rays are an outpatient procedure and are, therefore, one of the most financially efficient therapeutic modalities used for oncology. X rays have been studied for 100 years and are medically well understood. Conforming the high-dose region of radiation beams to the tumor volume and avoiding unnecessary irradiation of normal tissues has been and is the major thrust in radiation oncology. Protons, which are radiobiologically similar to X rays, do this exquisitely, thus reducing complications and morbidity. Ernest Rutherford discovered protons in 1919.