Radiotherapy saved and/or improved the lives of many patients. However, there are some potential long-term side effects to be aware of (see below), depending on which parts of the body were exposed to the radiation. Fortunately, in most cases, only the body parts subjected to radiation are affected.

• Cavities and tooth decay
• Early menopause
• Heart and vascular problems
• Hypothyroidism
• Increased risk of other cancers
• Increased risk of stroke
• Infertility
• Intestinal problems
• Lung disease
• Lymphedema
• Memory problems
• Osteoporosis

The list above is copied verbatim from mayoclinic.org