Cancer Radiation

 Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is called radiation oncology.

Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of cancerous tissue leading to cellular death.

To spare normal tissues (such as skin or organs which radiation must pass through to treat the tumor), shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger absorbed dose there than in the surrounding, healthy tissue. Besides the tumour itself, the radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumor, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumor to allow for uncertainties in daily set-up and internal tumor motion. These uncertainties can be caused by internal movement and movement of external skin marks relative to the tumor position.  Wikipedia

Common side effects of radiation therapy include:

Skin problems. Some people who receive radiation therapy experience dryness, itching, blistering, or peeling. These side effects depend on which part of the body received radiation therapy. Skin problems usually go away a few weeks after treatment ends. If skin damage becomes a serious problem, your doctor may change your treatment plan.

Fatigue. Fatigue describes feeling tired or exhausted almost all the time. Your level of fatigue often depends on your treatment plan. For example, radiation therapy combined with chemotherapy may result in more fatigue. Learn more about how to cope with fatigue.

Long-term side effects. Most side effects go away after treatment. But some continue, come back, or develop later. These are called late effects. One example is the development of a second cancer. This is a new type of cancer that develops because of the original cancer treatment. The risk of this late effect is low. And the risk is often smaller than the benefit of treating the primary, existing cancer.

Site-specific side effects of radiation therapy:

Some side effects depend on the type and location of radiation therapy.

Head and neck. Radiation therapy aimed at a person’s head or neck may cause these side effects:

• Dry mouth
• Mouth and gum sores
• Difficulty swallowing
• Stiffness in the jaw
• Nausea
• Hair loss
• A type of swelling called lymphedema
• Tooth decay

Learn more about dental health during cancer treatment.

Chest. Radiation therapy aimed at the chest may cause these side effects:

• Difficulty swallowing
• Shortness of breath
• Breast or nipple soreness
• Shoulder stiffness
• Cough, fever, and fullness of the chest, known as radiation pneumonitis. This happens between 2 weeks and 6 months after radiation therapy.
• Radiation fibrosis, which causes permanent lung scars from untreated radiation pneumonitis. The radiation oncologist knows how to lower the risk of fibrosis.

Stomach and abdomen. Radiation therapy aimed at the stomach or abdomen may cause these side effects:

• Nausea and vomiting
• Diarrhea

These symptoms will likely disappear after treatment. And your doctor can prescribe drugs to manage these side effects. Making changes to your diet may also reduce your discomfort.

Pelvis. Radiation therapy aimed at the pelvis may cause these side effects:

• Diarrhea
• Rectal bleeding
• Incontinence, which is when a person is not able to control his or her bladder
• Bladder irritation

Additionally, men and woman may have different symptoms.
Potential side effects for men include:

• Sexual problems, such as erectile dysfunction, which is the inability to get or maintain an erection
• Lowered sperm counts and reduced sperm activity. This can occur from radiation therapy to the testes or prostate. And it may affect a man's ability to father a child. Learn about ways to preserve your fertility.

For women:

• Changes in menstruation, such as having menstruation stop
• Symptoms of menopause, such as vaginal itching, burning, and dryness
• Infertility, which is the inability to conceive a child or maintain a pregnancy. This may occur if both ovaries receive radiation therapy. Learn about ways to preserve your fertility.

Radiation recall

• Radiation recall is a rash that looks like a severe sunburn. It is rare and happens when certain types of chemotherapy are given during or soon after external beam radiation therapy.
• The rash appears on the part of the body that received radiation. Symptoms may include redness, tenderness, swelling, wet sores, and peeling skin.

Typically, these side effects start within days or weeks of radiation therapy. But they can also appear months or years later. Doctors treat radiation recall with medications called corticosteroids. Rarely, you may wait until the skin heals before continuing chemotherapy.
Coping with side effects

Everyone’s experience with cancer treatment is different. Before treatment, ask your health care team which side effects you may develop.

And continue talking with the team throughout your treatment schedule. Communicate when side effects appear or worsen. That will allow your health care team to provide treatment options.