Radiotherapy uses x-rays to kill cancer cells or injure them so they cannot multiply. It can be delivered by an external beam or internally (known as brachytherapy).
During radiotherapy your body uses a lot of energy dealing with the effects of radiation. Many people feel very tired during and after treatment. This fatigue may last several weeks or months. You may not feel like having sex during this time, but physical affection such as hugs or hand holding can be very reassuring.
Depending on the area treated, you may also lose your appetite and lose weight. If you have hair in the area receiving radiotherapy, for example, your scalp, face or body, you may lose some or all of it during treatment. Usually it grows back and returns to normal after radiotherapy has finished.
Radiotherapy for men
Pelvic radiotherapy is commonly used to treat prostate, rectal and bladder cancer. It may affect sexual function by damaging blood vessels and nerves to sexual organs, resulting in erectile dysfunction. Radiotherapy to the pelvic area may also make ejaculating painful. This is because the urethra has become inflamed. The pain usually disappears a few weeks after the treatment has finished.
Temporary or permanently reduced sperm production is common after radiotherapy. If you want to father a child, talk to your doctor about having sperm stored before treatment starts.
Radiotherapy for women
If you are having internal radiation you will need to be admitted to hospital and take some precautions while the treatment is active.
The ovaries are often in the area that needs treating, but the radiation oncologist will try and keep radiation away from them. Radiotherapy to the pelvic area for cancer of the rectum, bladder or cervix can stop the production of female hormones in the ovaries. This can cause menopause-like symptoms such as a dry and itchy vagina. Scar tissue may form, and this will shorten and narrow the vagina. Sexual intercourse may be painful but you may still be able to reach orgasm with practice and time.
Menstruation may become irregular or stop during radiotherapy to the pelvic area. After treatment your periods may return but some women will be permanently infertile.
Radiotherapy to the breast area can cause the skin to become red and sore and develop a sunburnt look. Small blood vessels in the skin can be damaged causing red ‘spidery’ marks (telangiectasia), but this is becoming less common with new techniques.
Your skin may also have a slightly darker tone. It’s not unusual for the breast to feel firmer, and over months or years it may shrink slightly. If you’re unhappy with the shape of the breast or if it isn’t the same volume as your other breast, you can discuss this with your doctor. There may be techniques, such as reducing the size of your other breast, that can be done to improve the appearance. Changes often can’t be noticed under clothing.