It is possible her difficulty swallowing coming back is becuase of an esophageal stricture, caused by the radiation, that is getting worse. If so, that should be diagnosed as soon as posible since the surgery required to fix it will be much worse if it closes over all the way and (I know this from experience) it can. This can be diagnosed htorugh a modified barium swallow test--has she had one of those? She should definitely see some doctor as soon as possible and not accept a wait until she knows exactly what is causing this.

Nelie