What is the difference between palladium and iodine seeds?
A. Iodine and palladium seeds are nearly identical in their appearance. Both are 0.45 cm long (about the size of a grain of rice) and are implanted in the same way. Both emit low energy radiation. The primary difference between these two isotopes is the rate at which they give off their energy. Palladium gives up 90% of its energy within two months, while it takes approximately six months for iodine to release 90% of its energy. There are advantages to using both isotopes, which is described below in a related question. There is no proof that one seed is better or stronger than another. The doses and seed strengths, in fact, are prescribed to produce the same biologic effect. Often the choice will relate more to the physician’s preference and how they were trained and developed their clinical experience.
