Both external and internal radiation therapy have potential side effects.

External radiation therapy

Common side effects include:

  • Mild to moderate fatigue (fatigue tends to increase over the course of treatment)
  • Skin irritation — such as itchiness, redness, peeling or blistering — similar to what you might experience with a sunburn (skin irritation tends to increase over the course of treatment)
  • Breast swelling
  • Changes in skin sensation

Rarely, radiation therapy may cause:

  • Arm swelling (lymphedema)
  • Rib fracture or chest wall tenderness
  • Inflamed lung tissue
  • Heart damage
  • Secondary cancers, such as bone or muscle cancers (sarcomas) or lung cancer

Internal radiation therapy

Internal radiation therapy usually produces fewer skin reactions, although the treated area may be sore and tender for a few months after treatment.

Other possible side effects include:

  • Bruising
  • Infection
  • Rib fracture or chest wall tenderness
Feb. 13, 2014