[rrred rs nm What stuccific sotivitey ef a sicoriteie of S:Tdeut vowld ba aeoctred ¢ « = deliver the same dcse in the same length of tine? The answer to this question depends upon the time efter detonation to be FY3 hours, the sr ucific eat « ° tae tha. thu particle coms in cor vset with the shinw fate . frruming thAc ilu: ty walld hive to bo abest 250 uc / for the same size prrticte. Since the particle may bs washed off before six days have expired, one may consider the problem another way. What must be the specific activity of a particle at H¥3 hours to deliver this dose in the next 24 hours? hecording to Siraci¢svist (pace 4), only about 70% of a ples toy dose reed be celivir.d in enc day Aceeptirs this, then s particle with abeut tho eure ecbivity et H/3 hours would bs sufficient to deliver an ervthena dose in or: . E. a ba ag dsye