Radiation therapy (radiotherapy) uses high doses of radiation to kill cancer cells and keep them from spreading. There are external and internal radiation therapies. Depending on the patient’s condition, radiation therapy may be combined with chemotherapy or surgery.
External radiation therapy
A machine sends radiation to a specific portion of your body without touching you. A typical course of treatment is once a day, five days a week, anywhere from 2 to 10 weeks, depending on your condition. This is usually an outpatient treatment that doesn’t require you to stay in the hospital.
There are different types of external-beam radiation therapy, such as:
- Three-dimensional conformal radiation therapy
- Intensity-modulated radiation therapy
- Stereotactic radiosurgery (including Gamma Knife radiosurgery)
- Stereotactic body radiation therapy
- Intraoperative radiation therapy
- Proton therapy*
Talk to your physician to see which radiation therapy is the right treatment for you.
What to expect
After a consultation with your physician, a radiation oncologist and radiation therapist will use X-rays to help determine where your body will receive the radiation.
The radiation therapist will mark your skin to designate the treatment area. These marks will remain throughout the course of your therapy. Be careful not to remove them and let the therapist know if the marks fade.
We may make a body mold to help keep your body from moving during treatment and to ensure that you are in the exact position for each treatment. For radiation treatment to the head, a mask keeps your head in the same position for each treatment.
This type of external radiation therapy uses a narrow, high-powered radiation beam that focuses on a small area of the body. This targets the cancer cells better than more conventional radiation therapy.
Stereotactic radiosurgery treats tumors that are difficult to remove with surgery or patients who might be too weak for surgery. Conditions treated include:
- Brain metastases
- Pituitary tumors
- Uveal melanoma (cancer of the eye)
- Acoustic neuroma
- Spinal cord tumors
- Blood vessel malformations
- Movement disorders
- Some forms of epilepsy
- Parkinson’s disease
- Trigeminal neuralgia
- Liver cancer
- Lung cancer
- Prostate cancer
Internal radiation therapy
Internal radiation therapy (brachytherapy) delivers radiation in solid form such as seeds, capsules or even ribbons.
These are placed in the body at or near the cancer cells and delivers a high dose of radiation to a specific body area. Internal radiation can also be delivered in a liquid form, through a pill or intravenously. The liquid radiation travels through the body targeting cancer cells. Brachytherapy treats patients with cancers affecting:
- Head and neck
- Gall bladder
Liquid radiation is most often for:
- Thyroid cancer
- Non-Hodgkin lymphoma
Brachytherapy is typically placed with a catheter (thin tube), although it may be placed with a larger device called an applicator.
You will be sedated or anesthetized to prevent pain. If you feel pain or discomfort, let your physician or nurse know. They will give you medication to help you manage the pain.
The radiation may be kept in place for a very short period of time or for a long period of time, depending on your condition.
Types of brachytherapy
- Low-dose rate implants: Radiation is placed for 1 to 7 days, during which time you will likely be hospitalized. Once the treatment is finished, the radiation sources are removed
- High-dose rate implants: The radiation source is placed for 10 to 20 minutes at a time before it is taken out. Course of treatment may run twice a day for 2 to 5 days, or it may run once a week for 2 to 5 weeks, depending on the type of cancer. It may require a hospital stay or you may be able to come and go to receive the treatment
- Permanent implants: The radiation source is placed and will permanently stay in your body. The radiation source gets weaker each day, although, when initially placed, you must be careful to not spend time with children or pregnant women. Over time, the radiation release lessens and stops, even though the implant will remain
Depending on the radiation therapy, you must take particular precautions. Your physician or nurse will inform you of safety measures to take.
If you receive high-dose radiation, you may have to stay in a private hospital room to protect others from the radiation coming from your body. Specialists will provide the care you need but may keep a distance from you. Visitors may have to follow these precautions:
- No visitors immediately after initial placement of radiation sources
- Checking with hospital staff before they see you
- Visits lasting no more than 30 minutes each day, depending on the type of radiation and what area is being treated
- Staying at the door instead of entering the room
- No visits from children under 18 years or pregnant women
These precautions may also apply once you leave the hospital.
Effects on healthy cells
Radiation kills cancer cells but can also harm healthy cells. Your physician tries to protect healthy cells during the course of treatment through a variety of means.
- Using medicines: Certain drugs can help protect parts of your body exposed to radiation
- Treatment time: Spreading out the course of treatment over time allows normal cells to recover during therapy
- Precise targeting: Physicians can use intensity-modulated radiation therapy or 3-D conformal radiation therapy to more precisely aim doses of radiation at the cancer, reducing impact on nearby, healthy cells
- Low doses: Physicians determine the highest effective dose, while keeping dosages low enough to limit damage to healthy cells
Receiving radiation therapy does not hurt, although side effects from it may cause discomfort or pain. Your physician will help you manage any side effects of radiation therapy.
Life after radiation therapy
Once your course of treatment ends, you will need to regularly follow-up with your radiation oncologist or nurse to determine:
- Effectiveness of the radiation therapy
- The condition of your cancer
- Any additional side effects
Your physician will also see how you are feeling, whether you need any additional medicines. We may order additional lab tests or imaging tests.
You should be alert to any unusual symptoms after radiation therapy and should let your physician or nurse practitioner know about them, including:
- New lumps, bumps, swellings, bruises, rashes or bleeding
- Changes in appetite
- Nausea, vomiting, diarrhea or constipation
- Unexplained weight loss
- Pain, fever, cough or hoarseness that does not go away
- Any other unusual symptoms that cause concern
Radiation Therapy InformationLearn important information about these various procedures.
The physicians who practice at the Northwestern Medicine Proton Center are neither agents nor employees of Northwestern Memorial HealthCare or any of its affiliate organizations. These physicians have selected our facilities as the place where they want to treat and care for their private patients.