Radiation Therapy
OVERVIEW
What is radiation therapy?
Radiation is a special type of energy carried by waves or a stream of particles. It can come from radioactive substances and special machines. There are many different levels of radiation energy. We have all been exposed to low levels of radiation energy, such as radiation from the sun or radiation used to make a chest x-ray or mammogram. When radiation energy is used at high levels, it can treat cancer and other illnesses. The use of high-energy rays or particles to treat a disease is called radiation therapy.
Cancer is a tumor, or an overgrowth of abnormal cells. These cells grow by multiplying or dividing to rapidly make new tumor cells. Their ability to multiply without limits, grow quickly, and invade surrounding normal tissues makes cancer cells different from normal cells. There are many different types of cancer, each of which is unique in how it grows and how it responds to treatment. One way to stop the cancer from growing is to interfere with the cancer cell’s ability to multiply. Radiation, used at high doses, causes changes in the cancer cell that stops the cell’s ability to multiply and eventually kills the cancer cell.
Radiation therapy is one of four approaches to the treatment of cancer. The other three are surgery, chemotherapy, and biological therapy. Since each type of cancer is unique, research has helped physicians determine which treatment or combination of treatments is appropriate for each type of cancer. Radiation therapy may be used alone or in combination with surgery, chemotherapy, and/or biological therapy. It may be used in an attempt to cure the cancer or treat unpleasant symptoms the cancer is causing such as pain or bleeding. The most common types of cancer that radiation therapy is used for are brain tumors, head and neck cancers, lung cancer, breast cancer, prostate cancer, skin cancer, rectal cancer, cervix and uterine cancers, lymphoma, and sarcoma.
How is Radiation Therapy Given?
Radiation therapy for the treatment of cancer may be given in two different ways. External beam irradiation is the most common method. The radiation is delivered to a specific area of the body using a large machine similar to an x-ray machine. The treatment is given each day, Monday through Friday, for 1 to 8 weeks depending on the type of cancer and the purpose of the treatment. The treatment may be given once, twice, or as many as three times a day for certain cancers.
The other method of delivering radiation treatment is called brachytherapy. In this method, a source of radiation in the shape of needles or seeds is implanted in the body. This treatment is often given before or after external beam irradiation as a way of increasing the radiation dose directly to the tumor. Brachytherapy is often used in cervical, uterine, and prostate cancers, some head and neck cancers, and sarcomas. The implants are placed in the body while the patient is anesthetized in the operating room. Some of the implants stay in place permanently, whereas others are removed after 2 or 3 days.
Who Gives the Radiation Treatment?
At our Radiation Therapy centers a team approach to treating patients has been developed. The team consists of a radiation oncologist, physicist, dosimetrist, radiation therapists, and a nurse.
The radiation oncologist is a physician who has completed a residency in radiation oncology. The radiation oncologist is responsible for determining the role of radiation therapy in a patient’s care, planning the treatment, and evaluating the patient's response to the treatment. The physicist and dosimetrist help the radiation oncologist develop the treatment plan. They are responsible for designing the immobilization devices, generating the computer plan, calculating the dose of radiation, and conducting weekly checks to make sure the treatment is being given accurately. The radiation therapists are responsible for the simulation procedure and the daily treatments. Each day they position the patient for treatment, ensure that the radiation field is accurate, and deliver the treatment. They work closely with the radiation oncologist to identify any shifts or changes in the field before the daily treatment is administered.
The nurses are responsible for coordinating all of the patient’s care both during and after treatment, such as assisting the radiation oncologist with making appointments, evaluating symptoms related to the treatment, and making referrals for social services and nutritional evaluations as needed. In addition, they provide patient and family education regarding the treatment, it's side effects, medications, and long-term planning. Additional support staff include social workers, dieticians, secretaries, clerical staff, data managers, and research staff.