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Late Radiation Side Effects

Late side effects are those that first occur at least six months after radiation therapy is over.


Late side effects are rare, but they do happen. It is important to have follow-up care with a radiation oncologist or nurse practitioner for the rest of your life.

Brain Changes




Joint Changes



Mouth Changes


Secondary Cancer


Whether you get late side effects will depend on:

  • The part of your body that was treated
  • The dose and length of your radiation therapy
  • If you received chemotherapy before, during, or after radiation therapy


Your doctor or nurse will talk with you about late side effects and discuss ways to help prevent them, symptoms to look for, and how to treat them if they occur.


Some late side effects are brain problems, infertility, joint problems, lymphedema (a condition in which excess fluid collects in tissue and causes swelling in the arm or leg. It may occur after lymph vessels or lymph nodes in the underarm or groin are removed or treated with radiation), mouth problems, and secondary cancers.