Analysis of prostate seed loading for permanent implants

The goal of radioactive seed implantation in prostate cancer is to treat the tumor to the necessary dose while minimizing the dose to adjacent normal structures. The uniform and peripheral loading schemes used in the past have serious limitations. However, with the availability of three-dimensional treatment-planning systems, it has become possible to do custom volume loading based on volumetric ultrasound imaging of the gland. As a result, the dose distributions are more uniform, and the doses to the urethra and rectum are maintained in a safe range.