Radiation dose distributions in normal tissue adjacent to tumors containing (131)I or (90)Y: the potential for toxicity.

Unlabelled: Given the relatively large tumor-absorbed doses reported for patients receiving radionuclide therapy, particularly radioimmunotherapy, and the relatively long pathlength of the nonpenetrating emissions of some radionuclides being used for these therapies, there exists the possibility of large absorbed doses to tissues adjacent to, surrounded by, or surrounding these tumors. Because tumors can occur adjacent to critical organs or tissues, such as arteries, nerves, pericardium, and the walls of the organs of the gastrointestinal tract, large absorbed doses to these normal tissues can lead to acute complications.

Methods: In this study, the Monte Carlo radiation transport code MCNP4b was used to simulate the deposition of energy from emissions of 2 radionuclides of interest, (131)I and (90)Y, to assess the possible magnitude of the absorbed doses in tissues adjacent to tumors.