Postoperative vaginal cylinder brachytherapy in an era of 3D imaging

Postoperative adjuvant intravaginal brachytherapy (VBT) is frequently used in the treatment of post-hysterectomy endometrial cancer. The dose prescription point and treatment length vary between institutions. The bladder, rectum and sigmoid (organs at risk, OAR) are in the immediate vicinity of the brachytherapy dose and can be visualized at the time of simulation. Imaging with either 2D or 3D techniques allows for verification of applicator size, placement and doses to the OAR. 3D imaging also allows for verification of apposition of the apparatus to the vaginal walls and evaluates the dose to the OAR in a non-invasive manner. The use of 3D imaging and new applicators may permit dose sculpting in complex cases to cover the CTV or reduce dose to the OAR.