Penile cancer

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Potential side effects of radiation therapy for penile cancer

Side effects can occur with any type of treatment for penile cancer, but not everyone has them or experiences them in the same way. Side effects of radiation therapy will depend mainly on the:

  • size of the area being treated
  • specific area or organs being treated
  • total dose
  • treatment schedule
  • type of radiation therapy given

Radiation therapy kills cancer cells, but healthy cells in the treatment area can also be damaged, even though steps are taken to protect them as much as possible. Different cells and tissues in the body tolerate radiation differently.

Side effects can happen any time during, immediately after or a few days or weeks after radiation therapy. Most side effects go away shortly after radiation therapy is completed. Late side effects can occur months or years after radiation therapy. Some side effects may last a long time or be permanent. Side effects associated with external beam radiation tend to develop during treatment and will start to go away once treatment has finished. Side effects associated with brachytherapy tend to develop 1-2 weeks after the treatment has ended.

It is important to report side effects to the healthcare team. Many side effects can be relieved by medications, a change in diet or other measures. Sometimes radiation therapy treatments need to be adjusted if side effects are severe.

Skin reactions

Skin reactions occur because external beam radiation travels through the skin of the penis to reach the area being targeted for treatment. The skin in the radiated area may become red, swollen, dry or change colour (become darker or tanned looking). Areas of thickening or scarring (fibrosis) may also occur. Most skin reactions occur within the first 2 weeks of receiving radiation treatment. They usually go away a few weeks after treatment. Some skin changes, like skin darkening or scarring, can be permanent. Some men do not experience any skin reactions with radiation therapy.

Men are advised to practise good hygiene while having radiation therapy. Having frequent soaks with baking soda and water will help to keep the penis clean and prevent infection. Men can resume sexual intercourse once they are comfortable with it. Water-based lubricants are recommended to prevent excess friction while the skin is healing.

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Fatigue is one of the most common side effects of radiation therapy. Fatigue may be caused by anemia, poor appetite or depression. It may also be related to toxic substances that are produced when cancer cells break down and die. During radiation therapy, the body uses more energy to heal itself, so fatigue will not always be relieved by rest. Making daily trips for radiation treatments can also be tiring.

Radiation therapy to any area of the body can make a person feel more tired than usual, but fatigue is more common when larger areas of the body are treated. Fatigue is more likely to occur if radiation is given to the groin, pelvis and the penis.

Fatigue usually occurs during the second week of radiation treatment or later. Symptoms of fatigue may increase or become more severe over the course of treatment. Fatigue usually goes away gradually after treatment has ended, but some people continue to feel tired for several weeks or months after radiation therapy.

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Loose bowel movements

Loose bowel movements or diarrhea can occur when the lining of the intestines become irritated because of radiation therapy. Abdominal cramping may occur with diarrhea. Loose bowel movements or diarrhea often begin 2–3 weeks into radiation therapy. Men with advanced penile cancer who have radiation therapy to the pelvic lymph nodes have the highest risk for loose bowel movements.

Report diarrhea to the radiation therapy team. They can suggest over-the-counter or prescription medications to help relieve diarrhea.

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Painful urination

Painful urination (dysuria) may occur after radiation therapy. Symptoms usually occur within 2 weeks after radiation therapy is completed. They gradually go away 6–8 weeks after radiation is completed.

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Blood clots

Men receiving brachytherapy usually need to stay in bed at the hospital during the course of the treatment, which lasts 4-5 days. Lying in bed for long periods of time can cause the blood in the legs to clot. This may lead to a deep vein thrombosis (DVT), which is a blood clot in the deep part of the leg.

Leg exercises and blood thinners are often recommended to prevent blood clots.

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Radiation necrosis

Radiation necrosis is an area of dead tissue that forms at the site of a tumour treated with radiation. The area usually contains non-cancerous tissue that will be sore and doesn’t heal quickly. Radiation necrosis is more common after brachytherapy than external beam radiation therapy for penile cancer. The risk of radiation necrosis increases with the dose of radiation given, the number of radioactive sources (such as needles in brachytherapy) used and the size of the area treated. Radiation necrosis may occur 7–18 months after treatment, but may also occur later. Most cases of radiation necrosis will heal with good hygiene and antibiotics. In some cases, the doctor may recommend hyperbaric oxygen treatments.

Biopsies are usually avoided in men with radiation necrosis because of the pain associated with the procedure. However, sometimes a biopsy is needed to rule out a recurrence of cancer. A doctor may recommend surgery to remove the area of necrosis or may prescribe corticosteroids to relieve symptoms. Men are advised to practise good hygiene and use water-based lubricants during sexual intercourse to prevent symptoms from becoming worse.

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Narrowing of the urethra

Narrowing of the urethra (urethral stenosis) may occur after radiation therapy. It usually is a late side effect of radiation therapy and tends to occur at the opening of the urethra (meatus) within 3 years following treatment.

A dilator can be used to help widen the opening of the urethra. Severe cases of urethral narrowing may require surgery.

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Lymphedema (a buildup of lymph fluid in tissues, causing swelling) may occur in a man’s legs after radiation therapy. Lymphedema is more likely to occur if the lymph nodes in the groin were removed during surgery for penile cancer.

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A fistula is an abnormal opening that may occur between the urethra and the skin of the penis. Surgery is usually needed to repair a fistula.

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Reproductive problems

The reproductive organs may be affected by radiation therapy, depending on the amount of tissue treated and the dose of radiation therapy given. The radiation therapy team will often try to shield the testicles from radiation. Some radiation scatter (radiation energy that is given off outside the treatment area) may be unavoidable and the testicles may be exposed to small amounts of radiation.

Radiation therapy may lead to fertility problems and erectile dysfunction.

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A reduction in the number of healthy red blood cells.


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