STEPHEN SCHUSTER, MD: Iodine-131 is the isotope that's used in the Bexxar antibody. Yttrium-90 is isotope that's used in the Zevalin antibody.
ANNOUNCER: The radioactive particles in Zevalin emit beta radiation, which travels over a relatively short distance. The radioactive particles in Bexxar give off beta and gamma radiation. The gamma radiation travels a longer distance.
STEPHANIE GREGORY, MD: Beta radiation has a short path length and doesn't penetrate deeply into tissue and outside of the body. Gamma radiation is not stopped by anything short of lead, so it passes straight through the body out into the external environment and actually hits whatever is in its pathway.
ANNOUNCER: Safety issues for those in close contact with the patient depend on which medication is administered.
RUSSELL SCHILDER, MD: Yttrium-90 source of radiation is a pure beta emitter so there's absolutely no radiation that escapes the body. The only instructions they really have is to wash their hands, clean up any spills of bodily fluids quickly, to not share utensils for three days, to use condoms during sexual relations for the first week, though it's recommended that birth control be used for up to a year.
The other, if it's using iodine, as in I131, it is mostly a beta emitter but there's some gamma radiation and there are some slight differences depending on what state you live in as to the regulatory issues.
ANNOUNCER: Side effects for the patients themselves appear to be minimal.