  We used Monte Carlo simulations to study release of radium-224 daughter
nuclei from the seed used for Diffusing Alpha-Emitters Radiation Therapy
(DART). Calculated desorption probabilities for polonium-216 (15%) and lead-212
(12%) show that they make a significant contribution to total release from the
seed. We also showed that the dose to tissue from decays inside the 10mm long
seed exceeds 2.9 Gy for initial radium-224 activity of 111 kBq.
