Dosimetry of technetium-99m red blood cells labeled in vivo

Mean organ doses received from Tc-99m red blood cells labeled in vivo were calculated by the MIRD method using biodistribution data reported in the literature. The organ receiving the greatest dose was found to be the heart, followed closely by the bladder and stomach. Relatively high doses are also received by the blood, spleen, and lungs. Intermediate absorbed doses are received by the thyroid and kidneys, whereas organs with small blood concentrations and the remainder of the body receive the smallest doses. The major portion of the absorbed doses delivered to the stomach and the thyroid is due to the presence of free pertechnetate.