Brachythearpy is one of the latest advances in the treatment of breast cancer and is the most widely practiced method of balloon therapy.  In this method, a catheter with a balloon on the end is implanted into the breast where the tumor was removed.  The balloon is then inflated.  Twice a day for five days (early morning and late afternoon), a radio-active seed is inserted into the catheter and moved to the balloon to treat the target tissue.  The treatment is administered under the supervision of a radiation oncologist and is usually done in a hospital or clinic.  After each session of approximately 20 minutes, the seed is removed from the catheter.  A woman is free to go about her daily activities between appointments and is not radioactive.  When treatment is complete, after the five days, the balloon catheter is removed.