Radiation therapy uses high energy rays (such as x-rays) to kill or shrink cancer cells. Radiation therapy works by damaging the ability of the cancer cells to multiply and divide. When the cells die, the body naturally eliminates them. Healthy cells are also effected by radiation. That is why there can be side effects during the course of treatment. However, normal cells have a greater capacity to repair themselves than cancer cells can. Therefore, the majority of side effect are temporary.

The high energy rays used to kill the cancer cells are usually delivered by a machine outside the body called a linear accelerator. This is called external beam irradiation. Radioactive materials can also be placed directly in the tumor called internal or implant radiation, also called brachytherapy. External radiation is the type most often used to treat lung cancer.

External beam irradiation is used as the main treatment of lung cancer for those who may not be healthy enough to have surgery or whose cancer has spread too far to be removed by surgery. Often, chemotherapy is given at the same time as the radiation. For other patients, radiation may be used after surgery to kill small areas of cancer that cannot be seen and removed during surgery. Radiation can also be used to relieve symptoms such as pain, bleeding, or blockage of air passages by the tumor. It is also a treatment of lung cancer that has spread to other organs such as the bone or brain.

External beam radiation therapy is usually given in daily doses, five days per week. The radiation may be delivered over a period of two to seven weeks depending on type and stage of the cancer.

Cancer doctors, called Radiation Oncologists, specialize in treating cancer with radiation therapy. They will decide how to deliver the radiation therapy to best target the tumor but avoid as much of the normal surrounding organs as possible. Your tumor may be treated with 3 Dimensional Conformal Radiation Therapy which combines multiple radiation treatment fields to deliver precise doses of radiation to the lung tumor. Tailoring each of the radiation beams to accurately target the tumor protects nearby healthy tissue. IMRT may also be used to treat your tumor. This is even a more sophisticated form of 3D treatment planning that modifies the radiation by varying the intensity of each radiation beam. This technique allows the precise adjustment of radiation doses to the tissue within the target area, possibly allowing a higher radiation dose to the tumor, and keeping more radiation away from nearby normal tissues. Tomotherapy® may also be used to treat your tumor. This is a new and revolutionary way of delivering radiation with a high-output linear accelerator mounted on a CT scan gantry which rotates about the patient in a helical pattern. The radiation beam consists of tiny “beamlets”, each of which strike the patient from a full 360 degrees. Each beamlet can be independently switched on or off at any time depending on whether it is pointed at tumor or normal tissue. Tomotherapy can improve the accuracy and precision of treatment.

For small lung tumors in patients with limited lung function and who are not good candidates for surgery, Stereotactic Body Radiation Therapy (SBRT) offers an exciting treatment alternative. Radiation treatment planning for SBRT is a very complex and exacting process, using specialized “4-dimensional” CT scans that take into account the exact motion of the tumor with breathing. Large, focused radiation doses to very small regions of the lung can be achieved, and tumor control and cure rates are very competitive with surgery. Treatments are non-invasive, and are usually completed within one week. ROA offers this treatment on our Trilogy and Tomotherapy machines, which are both capable of delivering this highly sophisticated therapy. Please see the Stereotactic Body Radiotherapy/SBRT section for more details.