Letters to the Editor

The recent article, “Outpatient Administration of Radiolabeled Monoclonal Antibodies,” (Tuinstra, 2003) lists a platelet count of at least 150,000/mm3 as one of the eligibility criteria for patients to receive ibritumomab tiuxetan (Zevalin™, IDEC Pharmaceuticals, San Diego, CA) therapy. The U.S. Food and Drug Administration-approved criteria in the package insert (IDEC Pharmaceuticals Corporation, 2002) allows patients with platelet counts of at least 100,000/mm3 but less than 150,000/mm3 to receive Zevalin at a reduced dose of 0.3 mCi/kg to a maximum of 32 mCi. Patients with platelet counts equal to or greater than 150,000/mm3 receive 0.4 mCi/kg to a maximum of 32 mCi for their therapeutic dose.