Abstract
We experienced a case where the radioactive seed migrated to the right ventricle after 125I brachytherapy for prostate cancer. We could not estimate seed migration to either the coronary artery or right ventricle on non-CE conventional CT and chest X-ray. However, on coronary CT using 64 MDCT, we diagnosed the correct region of migration. It is considered important to evaluate the coronary artery using 64 or more MDCT synchronized with the electrocardiogram, if the seed exists at the level of the left lower lung on chest X-ray.