Radiation Therapy for Lung Cancer
Facts About Lung Cancer
- Lung cancer is the second most diagnosed cancer in men and women, but it is the number one cause of death from cancer each year in both men and women.
- According to the American Cancer Society, 219,000 Americans were diagnosed with lung cancer in 2009.
- Cigarette smoking is the most common cause of lung cancer.
- Exposure to asbestos, radon, environmental factors and secondhand smoke can also cause lung cancer.
Types of Lung Cancer
There are two main types of lung cancer, non-small cell lung cancer and small cell lung cancer. These names refer to how a cancer looks under the microscope.
- Non-small cell lung cancer is the most common type of lung cancer and accounts for 80 percent of cases. There are different types of non-small cell lung cancer, including squamous cell carcinoma, adenocarcinoma, bronchioalveolar carcinoma and large cell undifferentiated carcinoma.
- Small cell lung cancer is less common and accounts for 20 percent of cases. Although the cells are small, they multiply quickly and can form large tumors that may spread throughout the body. This type of lung cancer is almost always due to smoking.
Treating Lung Cancer
Lung cancer treatment depends on several factors, including the type and stage of the lung cancer and your overall health. The main treatment options are surgery, radiation therapy and chemotherapy. New treatments are also showing promise.
Non-small cell lung cancer (NSCLC):
- Non-small cell lung cancer can be treated with surgery, radiation therapy and/or chemotherapy.
- Stage I NSCLC (small tumor in the middle of the lung) is primarily treated with surgery. For patients who for health reasons cannot undergo surgery, stereotactic body radiation therapy may be an excellent alternative. It is non-invasive and is usually given in one to five treatments.
- Stage II NSCLC (larger tumors, extension outside of the lung itself, or early involvement of lymph nodes) is treated with surgery, followed by chemotherapy. Stereotactic body radiation therapy has not been well studied for these tumors, and conventional external beam radiation therapy would commonly be recommended for patients who for health reasons cannot undergo surgery.
- Stage III NSCLC (tumor extending into other organs or involvement of lymph nodes in the middle of the chest) can be treated in several different ways. For some patients, initial chemotherapy or chemoradiation therapy followed by surgery is a reasonable approach. For other patients, definitive chemoradiation therapy without surgery is preferred. The radiation typically takes six to several weeks.
- Stage IV NSCLC (tumor has spread from the lungs, and involves other locations such as the brain, the bone or the liver) is usually treated with chemotherapy. Radiation therapy is used for local control of tumor to prevent symptoms such as pain or neurological dysfunction similar to stroke and typically lasts one to two weeks.
Small cell lung cancer (SCLC):
- Small cell lung cancer most often is treated with radiation therapy and chemotherapy.
- Limited stage SCLC is disease confined to the chest. It roughly corresponds to Stage I-III for NSCLC above. It is primarily treated with simultaneous chemotherapy and radiation to the chest. Because there is a high rate of microscopic tumor deposits to the brain, giving radiation therapy to the brain (prophylactic cranial irradiation) is frequently offered after completion of the primary chemoradiation therapy to the chest. This is to kill any tiny cancer cells that may have spread to the brain.
- Extensive stage SCLC is metastatic disease, and corresponds to Stage IV NSCLC above. It is primarily treated with chemotherapy. Radiation therapy is used for local control of tumor to prevent symptoms such as pain or neurological dysfunction similar to stroke and typically takes one to two weeks of treatment.
In addition to your radiation oncologist and primary care physicians, several different healthcare professionals will be involved in your care.
- Thoracic surgeons are physicians who use surgery to remove cancerous tumors and tissue from the chest. They usually have specialized training in cancer surgery.
- Medical oncologists are doctors who specialize in treating cancer using various chemotherapy drugs.
Understanding Radiation Therapy
- Radiation therapy, sometimes called radiotherapy, is the use of high-energy X-rays to safely and effectively kill cancer cells.
- Radiation therapy works within cancer cells by damaging their ability to multiply. When these cells die, the body naturally eliminates them.
- More specifically, radiation therapy damages the DNA of the cancer cells. The DNA is a blueprint that tells each cell what to do and how to divide. When the cancer cell tries to divide next time, it realizes that its DNA has been damaged and dies instead.
- This process determines how quickly the tumor will respond to radiation therapy. Tumors that grow rapidly (such as small cell lung cancer) will discover their DNA has been damaged more rapidly, and will also die more rapidly. Tumors that grow more slowly (such as prostate cancer tumors), will also die more slowly, and it may take one to two years before they are completely eradicated. Non-small cell lung cancers may take weeks to months before being completely killed.
- Healthy cells are also affected by radiation, but they are able to repair themselves in a way cancer cells cannot.
- Radiation oncologists use radiation therapy to try to cure cancer, to control tumor growth or to relieve symptoms, such as pain.
External Beam Radiation Therapy
External beam radiation therapy is the safe and effective delivery of high-energy X-rays to your cancer. A radiation-delivery machine called 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. Treatments are painless and last less than 30 minutes.
- Radiation therapy uses multiple radiation fields to deliver high doses of radiation to the cancer while minimizing the radiation received by surrounding healthy cells.
- Three-dimensional conformal radiotherapy (3D-CRT) combines multiple radiation treatment fields to deliver precise doses of radiation to the lung tumor.
- Intensity modulated radiation therapy (IMRT) is a specialized form of 3D-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 IMRT that delivers high doses of radiation to small and very precisely defined targets over a shortened course of therapy, often in as few as three to five treatments. It requires specialized immobilization devices to hold the patient fixed in place, as well as taking specialized CT scan to identify the tumor before each treatment. SBRT is currently being studied for the treatment of selected patients with lung cancer.
- Proton beam therapy is a type of external beam radiation therapy that uses proton beams rather than X-rays. It is only available at a few clinics in the U.S. and is being studied to determine whether it may allow doctors to better keep radiation away from other parts of the body that don’t need treatment.
- Radiation oncologists are able to tailor each of the radiation beams to focus on the tumor while protecting nearby healthy tissue.
- More about external beam radiation therapy
Internal radiation or brachytherapy is the placement of radioactive material directly into or near your tumor. Before treatment your doctor will place one or two thin plastic tubes or catheters into your nose and into the airways of the lung where the tumor is located.
The tube or tubes are then connected to a brachytherapy machine. The tube serves as a channel to deliver a dose of radiation by briefly placing a tiny radioactive source near the lung tumor. The source is often the size of tiny seeds or ribbons.
There are two different situations when this might happen:
- The surgeon works with the radiation oncologist to place strands of radioactive seeds into the area from where the tumor was removed. The seeds will remain inside of your chest forever, and over the course of several months will deposit their radiation into the area immediately around where the tumor used.
- Your doctor and your physicist will discuss with you if you need to take any short-term precautions, but typically there are no radiation safety worries from you to other people.
For tumors involving trachea or the bronchus:
- If you have a tumor that is involving one of your breathing tubes (trachea or bronchus), your doctor may place one or two thin plastic tubes or catheters into your nose and into the airways of the lung where the tumor is located prior to treatment. The tube or tubes are then connected to a brachytherapy machine.
- The tube serves as a channel to deliver a dose of radiation by placing a tiny radioactive source near the lung tumor for a short period of time. You may undergo between one and five treatment sessions on separate days.
- Because the radioactive seeds are removed at the end of each treatment and will not remain inside of you, there is no radiation hazard from you to other people.
Possible Side Effects
- Side effects are different for everyone. Some patients feel fine during treatment while others may feel uncomfortable.
- Side effects are caused by the radiation beam passing through and damaging normal tissues and organs on its way to the tumor. The direction the beam travels through the body differs from patient to patient, and so their side effects may also be different
- Different organs respond to radiation in different ways. Some become damaged relatively quickly, and you may experience the side effects within two to three weeks after starting your treatment. Other organs become damaged slowly, and you may experience side effect anywhere from six months to many years after the treatment is ends.
- Be sure to talk to your radiation oncologist before your treatment begins which side effects you could expect, and how likely they will happen.
- Skin: Skin irritation, including redness, dryness, tanning, and itchiness. Skin breakdown and ulcer formation (“skin burn”) is extremely rare during lung cancer treatment.
- Hair: Loss of hair on your chest, but not the hair on your head. However, certain types of chemotherapy that may be given together with radiation may cause hair loss on your head as well.
- Lung: Shortness of breath, dry cough.
- Esophagus: Difficulty or pain swallowing, narrowing of the esophagus.
- Fertility: Chest radiation will not affect your ability to have children.
- Stomach: You should typically not experience any nausea, diarrhea or vomiting.
- General: Tiredness, fatigue, general "blah" feeling.
- Talk to your doctor about any discomfort or pain you may feel. He or she can provide treatments, nutritional supplements, dietary recommendations or medications to help.
- Everyone responds differently to the stress of cancer and treatment. In addition to your own friends and family, your doctors, nurses, social workers and support groups are all available to help.
Caring For Yourself During Treatment
- Get plenty of rest during treatment, and don’t be afraid to ask for help.
- Follow your doctor’s orders. In many cases, your doctor may ask you to call if you develop a fever of 101° F or higher.
- Ask if you are unsure about anything. There are no silly questions.
- It helps to bring a friend, family member or adult child with you to your appointments to help take notes and process the information.
- Tell your doctor about any medications or vitamins you are taking to make sure they are safe to use during radiation therapy.
- Eat a balanced diet. Radiation to the chest should not upset your stomach, so tell your doctor or dietician if food tastes funny or if you’re having trouble eating. They might be able to help you change the way you eat to help you feel better.
- If you develop a heartburn or discomfort when you swallow, tell your doctor or nurse. They might provide you with a special liquid mix you can take before you eat food, which will make swallowing easier.
- Treat the skin exposed to radiation with special care. Wear a shirt when you’re in the sun, avoid hot or cold packs, only use lotions and ointments after checking with your doctor or nurse, and clean the area with warm water and mild soap.
- Coping with cancer can be very stressful. Support groups and friends may be able to help.