Minimizing nuclear medicine technologist radiation exposure during 131I-MIBG therapy

131I-metaiodobenzylguanidine is a norepinephrine analog that concentrates in adrenergic tissue and has been shown to be an effective radiotherapeutic agent used to treat tumors of neural crest origin, particularly neuroblastoma, a sympathetic nervous system malignancy of children. The purpose of this study was to determine the radiation dose received by nuclear medicine technologists while preparing and administering 131I-metaiodobenzylguanidine therapy dosages, and if any changes could be implemented that would reduce a technologist's dose. The study involves the collection of total whole body doses received by technologists during the treatment of six patients. Patient dosages ranged from 9.25 to 31.1 GBq, with radiation exposures to the nuclear medicine technologists averaging 0.024 μSv per MBq administered to the patient. Subsequently, the doses received by the technologists were analyzed with respect to specific process steps performed during 131I-metaiodobenzylguanidine therapy including package receipt, dosage preparation, and dosage administration. Results show that the largest contribution to the technologist's whole body radiation dose (>83%) is received during the dosage administration process step. After additional shielding was installed for use during the dosage administration process step, technologists' doses decreased 80%.