Biodistribution of Na2[166Ho(DTPA)(H2O)] injected intravenously in 200 μl of Mes buffer into BALB/c Mice. The animals were sacrificed, and organs were sampled at 1, 4, 24, and 48 h, followed by measurement of the 166Ho 80.5 KeV γ-emission. Three animals were assayed at each time point, and reported values are the average of the % ID per g of tissue (σ range: 0.14–0.60% ID per g).