Radiation Side-Effects

Side Effects of Radiation Therapy

It’s very important to remember that every person reacts differently to radiation therapy. Any side effect you might have depends on the location of cancer, the dose of radiation being given and your general health.

Some side effects occur during treatment or shortly after and then dissipate weeks later. Some side effects occur during treatment and then continue for years or permanently. It is also possible to have delayed side-effects that show up several years later.

Prior and during radiation treatment, patients should discuss side-effects with their radiation oncologist to help anticipate or reduce the severity of any side effects. Palliative treatments might include skin lotions, mouth washes, pain medication, nutritional support and more. 

Because ACC is commonly diagnosed in the head and neck area, the following list of side-effects pertains to this area. This list is not all inclusive but includes common side-effects shared by patients.

Trouble swallowing, or difficult swallowing is called dysphagia. Many people who are getting radiation therapy to the head and neck area may have dry mouth due to reduced saliva which can make swallowing difficult. It may also be caused by mouth sores, an infection of the mouth or esophagus (the swallowing tube that goes from the throat to the stomach), or other problems. Patients may experience difficulty starting a swallow, food goes down the wrong pipe, or there is choking and coughing.

Difficulty eating and swallowing food can have a significant impact on a patient’s life after cancer treatment. Consuming enough nutrition is critical to recover after treatment. Recognizing this disorder early allows you and your doctor to implement an effective treatment plan.

Fatigue felt during radiation treatment is different from the fatigue of everyday life, and it might not get better with rest. Patients start to feel tired after a few weeks of radiation therapy. Fatigue usually gets worse as treatment goes on. It can last a long time, sometimes years. No lab tests or x-rays can diagnose or describe your level of fatigue. The best measure of fatigue comes from your own report to your cancer care team Managing fatigue is an important part of care both physically and emotionally and should be shared with your medical team.

In some cases, radiation therapy can cause hair to be thinned or lost in the area being treated. Most people find that their hair grows back after treatment ends, but your hair may be thinner or a different texture than it was before. Ask your cancer care team if you have any questions or concerns about hair loss.
Radiation therapy close to the ear can cause middle and outer ear problems and side effects. These may include inflammation, earwax blocking the ear, fluid building up, and stiff ear bones.  High doses of radiation can also cause sensorineural hearing loss due to damage to the inner ear, the auditory nerve, or the vestibular apparatus. This condition is not reversible. Damage to the vestibular apparatus can also cause dizziness and vertigo.

Radiation treatment is well recognized as a cause of hypothyroidism. The thyroid gland is located low in the central neck and is often in the path of the radiation beam for cancers of the larynx, trachea, hypopharynx, and esophagus. Therefore, damage to the thyroid gland can occur following radiation for head and neck cancers. This will result in hypothyroidism, or an underactive thyroid, which can actually be quite delayed in its presentation. The doctor should check thyroid function with blood tests, especially with new symptoms such as new onset of fatigue or significant weight gain. In general, hypothyroidism slows the body’s normal rate of functioning, causing mental and physical sluggishness that can range from mild to life-threatening.

Patients may develop thick phlegm related to dry mouth and inflammation of the mouth and throat. Symptoms are typically managed with swish and gargle therapy and frequent hydration and occasionally, some products or medications can help decrease the amount of mucus.

This is pain with swallowing. It can be initiated when the mouth and throat lining starts sloughing off and becomes inflamed (mucositis). It can be treated by swishing and swallowing liquids that numb the pain, or in some cases strong pain medication. Rarely, if a patient is not able to eat or drink for an extended period of time, a doctor might suggest placement of a feeding tube until the patient gets through the painful phase.

Oral mucositis is probably the most common, debilitating complication of cancer treatments, particularly chemotherapy and radiation.  Common signs are mouth sores (often soft whitish patches or pus in the mouth or on the tongue), swollen gums or mouth, difficulty swallowing or talking.   It can lead to several problems, including pain, nutritional problems as a result of inability to eat, and increased risk of infection due to open sores. An extreme case of the condition is called confluent mucositis.  In a worst case, the mucous membrane of the patient’s entire mouth and tongue can be coated by a white mucus coating. The combination of mucus, excess saliva and pain can make it difficult or even impossible to eat.

Perhaps, the most severe side effect is osteoradionecrosis (ORN), or bone death. The bone most commonly affected is the mandible and, less commonly, the maxilla. The bone often becomes exposed through the skin or mucosa and can progress to an actual fracture of the bone. Osteoradionecrosis (ORN) can cause severe pain as well as chronic and persistent infections. If ORN sets in, treatment might include antibiotics, frequent debridement, and sometimes even hyperbaric oxygen dives. In severe cases of ORN, where pain, infection, and the risk of fracture are present, removal of the diseased bone may be required.

Before beginning radiation therapy, a patient should see a dentist before treatment to make sure the teeth are in the best possible shape. This prevents post-treatment complications like ORN. Some dentists may also provide mouth guards (or dental/fluoride trays) to wear during treatment. This may help to protect the gums and teeth during treatment.

If a patient needs dental work after head and neck radiation, they should consider seeing a dentist who is familiar with the treatment of ORN.

Pharyngoesophageal (PE) stenosis is an area of narrowing in the pharynx or esophagus. This can be a delayed problem caused by radiation. This narrowing can make it difficult to eat, particularly solid food. If the PE segment becomes completely closed off, the patient won’t be able to eat or drink anything by mouth and will require a feeding tube placed directly into the stomach (gastric tube). Treatment of this complication might include frequent placement of dilating catheters down the throat to stretch open the narrowed segment or surgical removal of the blocked segment with flap reconstruction.

Your skin in the radiation treatment area might look red, swollen, sunburned, blistered or darker. After a few weeks, your skin might become flaky, itchy, or it may peel. These problems usually go away gradually after treatment ends. It’s important to communicate with your cancer care team about any skin changes. They can suggest ways to ease the discomfort, lessen further irritation, and prevent infection.

Taste changes will be more or less pronounced depending on the extent of the radiation field. Changes in taste generally occur by the end of the second week of radiation treatment. This will begin with the dulling of certain flavors and gradually the intensity of all flavors will dull or decrease. Some patients note that most foods begin to taste bitter or unpleasant. For the majority of patients, taste sensation will recover following treatment. This recovery is gradual, and depending on the extent of the radiation field and severity of taste change, can take from 3 months to over 2 years.
The term ‘trismus’ has been used to describe any restriction to mouth opening, including restrictions caused by trauma, surgery or radiation. This limitation in the ability to open the mouth can have serious health implications, including reduced nutrition, difficulty in speaking and swallowing, and compromised oral hygiene.  Trismus can be short or long-term depending on the extent of change in the chewing mechanism of the jaw (joint, bone, and muscles), and patient compliance to treatment exercises and best practices. Early treatment of trismus can prevent or minimize many of the conditions described above. 

The most common short and long-term side effect of radiation therapy for the treatment of head and neck cancer is xerostomia (dry mouth). It occurs when salivary glands are radiated or in the path of the radiation. The degree of permanent xerostomia depends on the volume of salivary gland exposed to radiation and the radiation dose. A common early complaint following radiation therapy is thick or sticky saliva.

Xerostomia increases the risk of dental cavities and dental disease due to the decreased amount of saliva in the mouth. Patients learn to manage xerostomia in a number of ways, including frequent drinking of liquids and the use of artificial saliva preparations and prescribed or over the counter medications. Also, certain medications given around the time of radiation might lessen the severity of xerostomia.