The site of your surgery should be sufficiently healed before you are fitted for a permanent, weighted prosthesis. Your physician will let you know when the correct time is. It may be as soon as 4-8 weeks after surgery, but everyone's healing process is unique. Aside from allowing time for the surgery site to heal, the effects of radiation treatment may leave the surgery area too sensitive for the constant minor movements a breast form in a bra can produce. Waiting for the proper time also allows for post-surgery swelling to recede, which could hamper a proper breast form fitting as well.