Brachytherapy implants with differently spaced Ir-192 seeds: a dosimetric study.

Brachytherapy implantations traditionally have been carried out with continuous line sources of radium. With the popularity of afterloading implantations, iridium-192 seeds in plastic ribbons have replaced radium in the United States, although continuous sources, such as iridium wires, are widely used in Europe. The authors analyzed the impact of the use of noncontinuous sources in brachytherapy implants. Computer simulations and film dosimetry of a two-planar implant were carried out. Seeds at standard spacing (1 seed/cm), nonstandard spacing (1 seed/6mm), and continuously arranged seeds were studied.