As none of the intracavitary devices have yet been used in rectal, vaginal, ovarian, endometrial, cervical or pelvic lymph node tumours directly (but have been used in the rectum to treat prostate cancer), it is important that to gauge the levels of energy and resultant cancer tissue destruction from a variety of different treatment energies. In this manner, the first phase of this trial is equivalent to the 'dose escalation' phase of a drug trial.