There are two types of radiation therapy. These two types of radiation therapy are external beam radiation also known as teletherapy and internal radiation therapy or brachytherapy. Both radiation types are helpful in treating the cancer tumors.
In first type among types of radiation therapy, radiations are projected from distance source and directed at the desire body part. Systems used in external beam radiation are Cobalt-60 machine, orthovoltage X-ray machine, linear accelerator, neutron beam machine and proton beam machine. Selection of the machine depends upon the treatment. Generally, oncologist selects the appropriate machine for the treatment. External beam treatment is best to treat the cancers of neck, head, breast, chest, colon, lungs and prostate.
According to the tumor locations, intensity of the radiation will depend. Surface tumors are treated with low energy radiation where as deeper cancer is treated with high-energy radiations. Another therapy among types of radiation therapy is stereo-tactic radiations that focus the radiation beam on small area and delivers high does of the radiation. External beam therapy is painless as radiations just focus the body.
In the internal radiation beam therapy, radiation sources are placed closely to the tumor. In some types of radiation therapy, sources are directly inserted into the tumor. The radioactive sources used are in the form of wires, rods or molds. A cervix, vagina, uterus, eye, rectum, head and neck cancer reduces effectively with this treatment. Treatment is also effective for brain, breast, skin, throat, lungs, anus, bladder and prostate cancers.
Some times treatment is used in combination with external beam therapy. Various types of the internal beam therapy are characterized with different methods of placing radiation inside the body. These types are intracavitary brachytherapy, interstitial brachytherapy, radioactively tagged molecules given intravenously and intraluminal radiation therapy.
In interstitial brachytherapy treatment, radioactive needles or wires are planted in the tumor area and taken out on same day, after several days or may keep permanently in the body. In case of intracavitary brachytherapy, radioactive sources are placed in body cavities by using metal or plastic devices.
These are main types of radiation therapy used for the treatments according to the type of cancer.