The most common forms of radiation therapy are external beam treatment, brachytherapy, and radioisotope treatment. The electron beams are used when a tumor is close to the surface, as they deliver a high dose close to the surface, which tapers off rapidly at a depth determined by the energy. Brachytherapy refers to radiation treatments given with radioactive material placed into the patient's body. Interstitial treatment involves the temporary or permanent placement of sources directly into tissue. Isotope treatment involves giving the patient radioactive material either as a pill or as an injection.
Radioisotopes are radioactive forms of naturally occurring elements.
The radioisotopes in common use for radiation treatments are produced either in nuclear reactors or in cyclotrons. The type and intensity of radiation differs, and different radioisotopes are therefore suitable for different applications. Contact radiotherapy involves the use of low energy radiation for the treatment of early stage rectal cancers. Our office is one of the few in this country to offer this modality of treatment.