For subjects with ≥150,000 platelets/mm3, the recommended dose was the activity of iodine-131 calculated to deliver 75 cGy of total body irradiation; for subjects with NCI Grade 1 thrombocytopenia (platelet counts ≥100,000 but <150,000 platelets/mm3), the recommended dose was the activity of iodine-131 calculated to deliver 65 cGy of total body irradiation.