Radiation Exposure to the Nuclear Medicine Personnel During Preparation and Handling of ~213Bi-Radiopharmaceuticals

摘要

Because of the excellent ability of a-particles to transfer a high amount of energy over a short tissue range, targeted a-therapy has been attracting rising numbers of nuclear medicine centers. In this study, we estimated the radiation exposure to the occupational workers with pocket dosimeters during handling of the alpha-emitter ~213Bi, used for targeted a-therapy of neuroendocrine tumor and castration-resistant prostate cancer patients. The dose rates from patients at different distances and time points after injection of the therapy were also evaluated. Methods: This prospective study was done in the Department of Nuclear Medicine at Fortis Memorial Research Institute, Gurgaon, India. Twelve patients with neuroendocrine tumors or castration-resistant prostate cancer were enrolled to receive ~213Bi-DOTATOC or ~213Bi-prostate-specific membrane antigen therapy, respectively. Each patient received 2-3 intravenous injections of ~213Bi-pep-tide, 266-362 MBq (7.2-9.8 mCi) in a single cycle over 2-3 d. The radiation exposure to nuclear medicine personnel at the chest and extremity levels was assessed for tasks such as elu-tion, dispensing, injecting, and collecting blood samples. Radiation levels were measured at distances of 1 cm and 1 m from patients immediately after, and at 1, 2, and 4 h after, the administration of ~213Bi-peptide. Results: The external dose incurred at the chest level by radiopharmacists during synthesis, by physicians during injection, by technologists during imaging, and by nurses during sample collection was 2-7 muSv/procedure. The extremity dose was 1-14 muSv/procedure. The dose rate at 1 m from patients immediately after ~213Bi-radiopharmaceutical injection was 0.02-0.03 uSv/MBq-h. Conclusion: The external radiation doses received by occupational workers involved in various procedures were far below the limit prescribed by the regulatory authority (20 mSv/y).