Some forms of radiation therapy may make patients radioactive for a certain period of time. External radiation therapy does not pose this risk, but internal radiation therapy does create an area of radioactivity around the implant. In addition, systemic radiation therapy involves radioactive materials circulating throughout the body. In these cases, some of this material leaves the body through saliva, sweat and urine. Certain precautions may be necessary to protect medical staff, visitors and others who come into contact with the patient following systemic radiation and internal radiation therapy.

Patients may be advised to observe the following:

• Wash hands thoroughly after using the toilet
  
  
• Flush the toilet several times after each use
  
  
• Use eating utensils and towels that are kept separate from others
  
  
• Do laundry separately
  
  
• Drink plenty of fluids to flush radioactive iodine from the body
  
  
• Avoid kissing and sexual contact
  
  
• Avoid prolonged contact with infants, children and pregnant women

While radiation therapy can be highly beneficial to cancer patients, it also can cause significant side effects. These are the result of damage to normal cells incurred during treatment. They usually will disappear once treatment has ended. Some side effects are general while others are likely to occur in the area being treated. Side effects can include:

• Fatigue. This is a symptom generally associated with radiation, but its cause is unknown. There is no single treatment for fatigue, but physicians can sometimes offer relief by treating the underlying causes of symptoms. Patients may be instructed to take more frequent naps or modify their daily activities. Also if a patient has anemia, blood transfusions or medications may be ordered to stimulate production of red blood cells.
  
  
• Skin problems. Early in treatment, a faint redness may develop at the site, followed by dryness and peeling. The skin may also become darker and itchy. Moisturizers may help relieve these symptoms. In some patients, extreme weeping and peeling may eventually develop, or thinning or hardening of the skin. A physician can best address how to treat these developments.
  
  
• Mouth problems. Inflammation of the mouth lining (mucositis) may occur with radiation in the head and neck area. Dryness and loss of taste in the mouth also can occur, and can be permanent in the worst cases. Some patients may develope dysphagia (swallowing problems) during the treatment period. These individuals may be referred to a speech-language pathologist for therapy or to a dietitian for nutritional support.
  
  Head and neck cancer patients may be given a radioprotector to help protect healthy tissues from radiation damage. Medications also can be prescribed to improve saliva production. Patients should be careful to keep their mouths clean to reduce the chance of infection. Finally, radiation can sometimes increase the chance of dental problems, such as cavities or loss of teeth. A dentist should be consulted about preventative care prior to radiation treatments of the head and neck.
  
  
• Cognitive problems. Significant changes in brain function can sometimes occur when the radiation is for primary or metastatic brain cancers. These problems can include memory loss, diminished sexual desire and poor tolerance of cold temperatures. In some cases, a large area of dead cells collects in the brain, a condition known as radiation necrosis. This occurs months to years after radiation treatments. In rare cases it can be fatal.   
  
  
• Lung problems. Radiation treatments of the chest area can cause a decrease in surfactant, the substance that keeps the air passages open. This may result in coughing and shortness of breath. Steroids are sometimes prescribed to reduce inflammation. Fibrosis (stiffening and scarring) can occur later, significantly reducing breathing capacity.
  
  
• Cardiac problems. Radiation therapy to the chest has been associated with eventual development of heart disease, including heart attacks. Such problems have occurred many years after radiation treatment and in many cases, the treatment involved much stronger doses of radiation than are currently used for most cancers.
  
  
• Gastrointestinal tract. Radiation in the abdomen may result in swelling or inflammation of the esophagus or intestines. This can cause nausea, vomiting or diarrhea. Antacids can help, as can a diet low in spicy, fried or high-fiber foods. For patients who develop severe nausea and vomiting, certain prescription drugs may help reduce these side effects. In severe cases, dehydration may require administration of intravenous fluids.
  
  
• Reproductive organs. Radiation of the testicles can cause permanent loss of sperm production, while radiation of the abdomen in women can damage the ovaries. In most cases, only one ovary will be involved in radiation therapy, which lessens the likelihood of infertility.
  
  Pelvic radiation can cause the vagina to become tender and inflamed for weeks following radiation. Scarring can narrow the vagina, making intercourse difficult. Pelvic radiation can also damage the arteries that carry blood to the penis, making it difficult to maintain erections.
  
  
• Secondary cancers. Radiation therapy now targets cancers mores precisely, which makes the development of second cancers less of a problem than in the past. The risk remains, but it is low and should be weighed against the potentially life-saving benefits of radiation therapy.