Radiation therapy uses high-energy x-rays, gamma rays, or particles to kill cancer cells. It may be used in different situations for laryngeal and hypopharyngeal cancers.
- Radiation may be used as the main (primary) treatment of some laryngeal and hypopharyngeal cancers. If the cancer is small, it can often be destroyed by radiation without surgery. This treatment can help to preserve better voice quality.
- Radiation can be used to treat some patients whose general health is too poor for surgery.
- It may be used after a cancer is removed with surgery, to try to kill any small areas of cancer that may remain and lower the chance the cancer will come back. This is called adjuvant treatment.
- Radiation therapy can be used to ease symptoms of advanced laryngeal and hypopharyngeal cancer such as pain, bleeding, trouble swallowing, and problems caused by spread of cancer to the bones.
Often, chemotherapy is given along with the radiation. This combination, called chemoradiation, can be more effective than radiation alone, but it also has more side effects. (See the “Chemotherapy” section for more details.)
Types of radiation therapy
There are 2 main types of radiation therapy.
External beam radiation therapy
In the most common type of radiation therapy to treat laryngeal and hypopharyngeal cancer, radiation from a source outside the body is focused on the cancer.
Before your treatments start, the radiation team will take careful measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. Radiation therapy is much like getting an x-ray, but the radiation is stronger. The procedure itself is painless. Each treatment lasts only a few minutes, although the setup time— getting you into place for treatment — usually takes longer.
External beam radiation therapy for laryngeal and hypopharyngeal cancer is usually given in daily fractions (doses), 5 days per week, for about 7 weeks. Other schedules for radiation doses have been studied in clinical trials.
Hyperfractionation refers to giving the total radiation dose in a larger number of doses (2 smaller doses per day instead of 1 larger dose, for example). Accelerated fractionation means that the radiation treatment is completed faster (6 weeks instead of 7 weeks, for instance).
Hyperfractionation and accelerated fractionation schedules may reduce the risk of laryngeal and hypopharyngeal cancer coming back in or near the place it started (called local recurrence) and may help some patients live longer. The drawback is that these schedules also tend to have more severe side effects.
Several newer techniques help doctors focus the radiation more precisely, and may be helpful in some situations.
Three-dimensional conformal radiation therapy (3D-CRT): 3D-CRT uses the results of imaging tests such as MRI and special computers to precisely map the location of the tumor. Several radiation beams are then shaped and aimed at the tumor from different directions. Each beam alone is fairly weak, which makes it less likely to damage normal tissues, but the beams converge at the tumor to give a higher dose of radiation there.
Intensity modulated radiation therapy (IMRT): IMRT is an advanced form of 3D therapy. It uses a computer-driven machine that actually moves around the patient as it delivers radiation. In addition to shaping the beams and aiming them at the tumor from several angles, the intensity (strength) of the beams can be adjusted to minimize the dose reaching the most sensitive nearby normal tissues. This may let the doctor deliver a higher dose to the tumor. Many major hospitals and cancer centers now use IMRT as the standard way to deliver external beam radiation.
Brachytherapy
Internal radiation therapy, also known as brachytherapy, uses radioactive material placed directly into or near the cancer. Brachytherapy may be used alone or in combination with external beam radiation therapy. It is rarely used to treat laryngeal and hypopharyngeal cancer.
Side effects of radiation therapy
Many people treated with radiation to the neck and throat area have problems with painful sores in the mouth and throat. These sores can make eating and drinking very hard, and can lead to weight loss and malnutrition. The sores heal with time after the radiation has stopped.
Some less severe side effects of radiation therapy may include:
- Mild skin problems (similar to a sunburn)
- Dry mouth
- Sore throat
- Worsening of hoarseness
- Trouble swallowing
- Loss of taste
- Possible breathing trouble from swelling of the larynx
- Tiredness
Most of these side effects go away after a short while. Side effects of radiation tend to be worse if chemotherapy is given at the same time. Tell your doctor about any side effects you have because there are often ways to help.
Radiation can worsen any tooth problems that already exist. Depending on the expected radiation plan and the condition of your teeth, some or all of your teeth may need to be removed before starting treatment.
Radiation aimed at areas near the salivary glands may damage them, leading to dry mouth that does not improve with time. In addition to discomfort and problems swallowing, a dry mouth can lead to tooth decay. People with dry mouth after radiation must pay close attention to their oral health.
When radiation is used as the main treatment for cancer of the larynx, it may very rarely lead to breakdown of the cartilage in the throat. If this occurs, the patient may need to be treated with a tracheostomy or laryngectomy.
For more information on radiation therapy, see our document, Understanding Radiation Therapy: A Guide for Patients and Families.
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