Radiation oncology is the practice of using radiation to treat cancer. The practice is over 100 years old. Since that time, radiation oncology has seen many advances (the MegaVoltage machines, the use of CAT-scan based treatments, IMRT).

Cancer cells are cells that have one goal: to keep dividing. They do not listen to normal feedback mechanisms that tell them to stop dividing. Even though all cancers love to keep multiplying, they are not all the same. Different ones respond differently to radiation treatments. Because of this, different cancers are treated with different radiation doses and different treatment schemes.

Radiation oncologists use radiation (X-rays) to kill cancer cells. The X-rays are similar to the X-rays used for getting a chest X-ray or for getting a X-ray for a broken bone, but have much more energy. Although radiation can damage normal cells, normal cells usually recover faster and more fully than cancer cells. This difference in recovery from damage allows the radiation oncologist to use daily treatment to preferentially kill cancer cells.

There are two forms of radiation therapy:

External Beam Radiation Therapy (EBRT)

Also called teletherapy (long distance therapy). This is the form of radiation most patients receive and the one shown in the movie below. In this particular case, you are brought into the treatment room by the radiation therapist. Then, the therapist will lay you on a treatment bed. The machine will be turned on and radiation will pass through your body. The treatment last about 10minutes and then the machine is turned off. Treatment itself is painless. Patients do not see or feel anything during treatment. You will not be radioactive and it is safe for you to interact with others. You will not expose others to radiation. There are different forms of EBRT, including 3-D conformal, Intensity Modulated Radiation Therapy, and Stereotactic RadioSurgery.

Brachytherapy

Unlike teletherapy where the radiation source is far away and transiently passes through your entire body, brachytherapy has the radioactive source near or within the tumor. During your brachytherapy you will be radioactive and will need to take special precautions.

Radiation therapy is usually directed at one particular part of the body (i.e., the lung). Even within that particular body part (i.e., the lung), the radiation beam is targeting a small region (i.e., the left upper lung). Determining where to aim the beam and how to position your body for daily treatments happens during the simulation.

The first step will be seeing the radiation oncologist in consultation. During this time, he or she will speak with you about your condition and determine if you need radiation. He or she will also explain the specifics of your treatment. OHSU is a teaching hospital, so before seeing the attending physician you may see a medical student or a resident physician. This may be considered beneficial because more people will be involved in your care.

Click here to tour the Department of Radiation Medicine

Simulation is the process where the doctor and the radiation therapist figure out the logistics of your treatment.

First, you are brought back to the simulation room and then you are positioned on the simulation table. To ensure that your position on the treatment table is reproducible, a VacLok or Aquaplast mask is sometimes made. Next, fluoroscopy is used to figure the target area. Then, an X-ray film is taken of that area. Finally, small permanent tattoos are made on your body depicting the borders of the radiation field. These tattoos help to line you up once you start your daily treatments.

Once this is done, you may require a CAT-scan. A CAT-scan allows for 3-D conformal treatment planning. It is not for diagnostic purposes. The CAT-scan data is subsequently put into a computer. The radiation oncologist then contours in the target area (i.e., the cancer) as well as avoidance structures (i.e., the heart). This allows the radiation beam to home in on the cancer and avoid other structures.

Treatment usually begins one to three weeks after your simulation. During this time, the radiation oncologist is planning your treatment

Radiation treatment is painless.

The radiation machine may make some noise, but we have a CD-player for your listening pleasure during the treatment. Feel free to bring your favorite CDs with you.

You will be in the treatment room alone. However, there are video cameras and an intercom on at all times. The radiation therapist is constantly watching the video monitor. To make a request during treatment, simply speak out and they will respond promptly.

If needed, they can stop the treatment machine at any time to address your concerns. Once you feel okay, they will re-start the treatment machine. Treatment usually last about 10 minutes.

Radiation is usually given 5 days a week, Monday through Friday. Each session is fairly short; from the time you come into the clinic, wait for your turn, get your treatment, and are able to leave takes about 45 minutes. For most types of cancer, radiation therapy lasts from 5 to 7 weeks.

Side effects are related to site being radiated. Certain side effects are seen with most types of radiation therapy and go away a few weeks after radiation therapy has finished. These are the most common side effects experienced.

Fatigue: You may have some fatigue, usually noticeable after a few weeks of radiotherapy. You should still be able to do all your normal activities, though you may not be able to do them for as long. You may require an additional nap in the afternoon towards the end of treatment and will require more hours of sleep at night.

Sunburning of skin: You may notice your skin becoming dry, itchy, and red. This is seen about 4 weeks into treatment and most noticeable on patients receiving radiation for head and neck cancers or breast cancers. You may purchase some alcohol-free aloe-vera gel prior to beginning radiation treatment. You can start applying the gel to the site where radiation will be given. Do not apply the gel before your daily radiation treatments; instead apply it after your treatment.

Hair loss: This will be limited to the area under treatment. Unless you are receiving chemotherapy or brain radiation, you will not lose the hair on you head.

Loss of appetite: This can happen for a multitude of reasons. The best thing you can do is to take in as many calories as possible. Because you have cancer and are receiving radiation therapy, your body's caloric demand is much greater than normal. This means that you have to eat more than before just to maintain your weight. The best way to do this is to eat many small meals throughout the day. Supplement this with high calorie drinks like Boost or Ensure.

You should still be able to do all your normal activities, though you may not be able to do them for as long. Radiation therapy alone will not put any restriction on your activities, although your cancer or other medical problems might.

We use the latest technologies to treat cancer. Learn more about the equipment used during treatment.

3-D conformal therapy allows us to go to higher doses without increased toxicities to normal structures. Any time a CAT-scan is used to plan out treatment, it is referred to as 3-D conformal treatment. With the CAT-scan, the radiation oncologist is able to determine the 3-D shape and volume of the tumor. Multiple different radiation beams and angles are then used that conform to the tumor. This allows the radiation oncologist to maximize the dose to the tumor and minimize dose to normal nearby structures.

IMRT stands for Intensity Modulated Radiation Therapy. It is a sub-type of 3-D conformal therapy. This is one of the latest technologies in radiation oncology. It gives the radiation oncologist a way to deliver high doses to the cancer, while avoiding sensitive normal organs.

IMRT allows the radiation oncologist to sculpt the radiation beams much more precisely than with conventional 3-D conformal therapy. IMRT is used when a radiation sensitive organ is nearby the cancer, or when trying to give a very high dose to a tumor. IMRT is frequently used for head and neck cancers and prostate cancer.

Brachytherapy translates to short therapy, where the radiation is placed in or near the cancer. Because the radiation source is placed within or near the cancer, the cancer receives a very high dose, while most normal tissue receive little, if any, radiation.

The radiation source can be placed either temporarily or permanently. These sources may be placed into a cavity (endocavitary brachytherapy), within the body tissue (interstitial brachytherapy), or within the bronchus (endobronchial brachytherapy). Brachytherapy is only used for some types of cancers and may be paired with external beam radiation therapy (EBRT). When paired with external beam radiation therapy, brachytherapy is usually given after EBRT.

Temporary Sources: Defined as either Low dose rate (LDR) or High dose rate (HDR) depending on how much dose they give per minute. LDR procedures take 2 to 5 days to deliver, while HDR procedures take a few minutes. Once an adequate dose has been reached, the source is removed. Temporary LDR is used at OHSU for certain endometrial and cervical cancers (Cesium137 sources), some head and neck sites, and biliary tree cancers. Chorodial melanomas are also treated with LDR (Iodine 125 sources). HDR is used for endobronchial, esophageal, and most gynecology cancers.

Permanent Sources: These radioactive sources are placed near or within the tumor and stay there permanently. Iodine 125 or Palladium 103 are used for permanent prostate seed implants. Permanent seed placement requires 3 steps, pre-planning stage, placement of the seed, and post-implant dose calculations.

• During the pre-planning stage, an ultrasound image of the prostate is acquired. This is then used to plan the distribution of seed placement within the prostate. The plan is reviewed and approved by the doctor.
• Seed placement is an outpatient procedure. You are usually home by late afternoon.
• For the post-implant dose calculation, a CAT-scan of the pelvis is performed about one month after the implant. Based on this CAT-scan, a final dose calculation is performed.

Patients who are scheduled to undergo bone marrow transplantation (BMT) may undergo whole body irradiation prior to BMT. During TBI, the entire body receives a homogenous dose of radiation. Because the dose rate at which radiation is delivered is low (6 to 13cGy/min), a single treatment usually last for 20-30minutes. TBI may be one day or may last up to 4 days.

Non-myeloablative TBI: Patients who receive the one fraction (treatment) of TBI undergo non-myeloablative therapy. Non-myeloablative means that the radiation will not kill the bone marrow cells. This treatment is very well tolerated with few long-term side effects related to the radiation treatment.

Myeloablative TBI: Patients who receive the three to four days of TBI undergo myeloablative therapy. Myeloablative means that the radiation kills the bone marrow cells. This treatment is well tolerated.

Side effects

• During treatment: Patients may have some fatigue, parotid tenderness, or nausea.
• Long term: Risk of alopecia (hair loss), cataract formation, hypothyroidism, pneumonitis (inflammation of the lungs), carditis (inflammation of the lining surrounding the heart), veno-occlusive disease of the liver (blockage of vessels in the liver), and sterility.

Patients with certain lymphomas of the skin are treated with total skin electron beam therapy. Unlike other forms of radiation treatments, which use photons to treat cancer, this particular type uses electrons. Electrons are useful because most of the radiation dose is directed absorbed into the skin.

Low-dose total skin electron beam therapy is usually done over 10 treatments, Monday through Friday. Because we give a homogenous dose to the entire skin, the patient is standing during treatment. We use the Stanford technique, where the patient stands in six different positions each day.

This is a very specialized way to deliver a very high dose of radiation therapy to a very small volume. Unlike any surgeries, there is no cutting involved. Arteriovenous malformations, acoustic neuromas, meningiomas, and other small brain tumors may be treated with SRS. It is an outpatient-based procedure. After your consultation, you may need to have an MRI of the brain done. This usually occurs the day before treatment.

Treatment day is long, requiring you to stay the full day in our department. When you first come in, our nurse will go over the entire day's events with you. Then, the physician will come in and address any concerns or questions you may have. After this, the neurosurgeon will place a head frame on. This takes about 5 to 10 minutes and afterwards you are taken for a CAT-scan. The CAT-scan data is put into the computer planning program. The head frame serves as a point of reference and allows the radiation beam to precisely home in on the tumor. While the planning is underway, you will be resting in one of the patient rooms. During this time, you may read, watch TV (we have a TV and DVD player, as well a selection of DVD movies), or talk with family members.

You may eat after you CAT-scan, which usually happens early in the morning. Finally, at the end of the day, you will have your treatment. Treatment is anti-climatic; you will not see or feel anything during treatment. Treatment lasts approximately 20 to 45 minutes. Once treatment is finished, the neurosurgeon will remove the head frame. Then, you are ready to go home. Treatment is well tolerated, though you may have a headache for a few days.

Mammosite is a way to partially irradiate the breast. It allows the radiation oncologist to deliver radiation right to the tumor bed, while avoiding normal breast tissue. Once the tumor is removed, the surgeon places an empty balloon into the cavity previously occupied by the cancer. At the time of radiation, we inflate the balloon and insert a radioactive source inside it. No source of radiation remains in your body between treatments or after the final treatment is over.

Cancer is a group of cells that divide quickly and grow out of control. To control, or even cure, your cancer, Chemotherapy is used. Everyone's cancer is different and so is the chemo that is given. You and your doctor will decide on what chemo is best for your situation and your type of cancer.

Most chemo drugs are given in one of the following ways:

• You might simply swallow a pill. If your chemo is a pill or liquid, you can often take it at home, but you need to follow your doctor's directions.
• Chemo can be given like a flu shot. The shots may be given in your doctor's office, a hospital, a clinic, or at home.
• Most often, chemo is given right into your veins through a needle or tiny plastic tube. This is called an IV (intravenous) injection.
• You may take chemo once a day, once a week, or even once a month, depending on the type of cancer you have and the chemo you are taking. How long you take chemo also depends on the type of cancer, how you respond to the drugs, and what length of time research has shown produces the best treatment results.

Learn more about Chemotherapy