External Beam Radiation Therapy

External beam radiation therapy (also called radiotherapy) is the safe delivery of high-energy X-rays to your cancer. A linear accelerator focuses the radiation beam to a precise location in your body for an exact period of time. Radiation is given in a series of daily treatments, Monday through Friday, for several weeks. In small cell lung cancer, two treatments may be given each day. The full course of treatment varies but can span three to seven weeks.

Before beginning treatment, you will be scheduled for a planning session to map out the treatment area. This procedure is called a simulation. You will undergo a CT scan to design your treatment and small tattoos will be made on the skin to make sure your treatments are accurate.

Different techniques can be used to give radiation for lung cancer.

• Three-dimensional conformal radiotherapy (3-D CRT) combines multiple radiation treatment fields to deliver precise doses of radiation to the lung tumor. Radiation oncologists are able to tailor each of the radiation beams to focus on the tumor while protecting nearby healthy tissue.
• Intensity modulated radiation therapy (IMRT) is a specialized form of 3-D CRT that modifies the radiation by varying the intensity of each radiation beam. IMRT is still being studied for lung cancer.
• Stereotactic body radiation therapy (SBRT) is a specialized form of radiation that delivers high doses of radiation to small and very precisely defined targets over a shortened course of therapy, usually in five treatments or less.
• Proton beam therapy is a type of external beam radiation therapy that uses proton beams rather than X-rays, which can give less radiation to normal tissue. The benefits of proton beam therapy over other external beam radiation therapies are still being studied.