Brachytherapy is an advanced cancer treatment. Radioactive seeds or sources are placed in or near the tumor itself, giving a high radiation dose to the tumor while reducing the radiation exposure in the surrounding healthy tissues. The term "brachy" is Greek for short distance. Brachytherapy is radiation therapy given at a short distance: localized, precise, and high-tech.
With High-Dose Rate (HDR) Brachytherapy, thin catheters are first placed in the tumor. The catheters are then connected to an HDR afterloader. This machine contains a single highly radioactive iridium pellet at the end of a wire. The pellet is pushed into each of the catheters one by one under computer control.
The computer controls how long the pellet stays in each catheter (dwell time), and where along the catheter it should pause to release its radiation (dwell positions). With a few well-placed catheters in the tumor, HDR brachytherapy can provide a very precise treatment that takes only a few minutes. After a series of treatments, the catheters are removed, and there are no radioactive seeds left in the body.treatments, the catheters are removed, and there are no radioactive seeds left in the body.