Nuclear Regulatory Commission Public Meeting
September 29-30, 2008
Security and Continued Use of Cesium-137 Chloride Sources
Issue 3 – Possible phase-out of CsCl sources
Jed Gorlin, MD, MBA
AABB Board of Directors
AABB is an international association dedicated to advancing transfusion and cellular therapies worldwide. Our members include more than 1,800 hospital and community blood centers and transfusion and transplantation services as well as approximately 8,000 individuals involved in activities related to transfusion, cellular therapies and transplantation medicine. For more than 50 years, AABB has established voluntary standards for, and accredited institutions involved in, these activities. AABB is focused on improving health through the advancement of science and the practice of transfusion medicine and related biological therapies, and developing and delivering programs and services to optimize patient and donor care and safety. We appreciate the opportunity to comment today on the issue of Security and Continued Use of Cesium-137 Chloride Sources.
Blood components are irradiated to prevent transfusion associated-graft-versus-host disease (TAGVHD) from white blood cells in cellular blood components such as red cells or platelets. Once established, TAGVHD is usually untreatable and often fatal. While not all patients require irradiated blood, those whose immune systems are compromised or who are receiving blood from immunologically similar donors, such as family members are at particular risk of this complication. Hence, it is imperative to balance the risks and benefits of phasing out Cesium in favor of alternative strategies. Respondents to the 2007 National Blood Collection and Utilization Survey reported that 2,322,000 blood components were irradiated in 2006. Many of these are concentrated at institutions that take care of cancer patients.
The recommendation to phase-out cesium sources for blood irradiators would pose significant hardship on many establishments, logistically and financially. Due to the space requirements and cost of X-ray technology, many smaller establishments may opt to rely on X-ray equipment, such as linear accelerators utilized by therapeutic radiology departments within the establishment or contract out the service. Either of these options would result in a delay for processing the unit(s), thus negatively affecting the care provided to those who are in critical need of blood components, or put the recipient at risk in the event that transfusions were to be initiated prior to the availability of irradiated components.
Logistically it would be impossible for manufacturers to replace all cesium source irradiators in the immediate future. There are a limited number of suppliers that manufacture alternative technologies which do not maintain an adequate inventory or the means to rapidly manufacture enough devices to replace the 700+ devices currently in use. Furthermore, the total number of devices would likely increase to create sufficient back-up capacity in light of the known increased down time of X-ray units (25% greater than 30-days). Even if there were sufficient alternative technology devices available, there is limited capacity for the removal the current cesium devices – the largest manufacturer has a limited number of specially equipped trucks and trained personnel capable of handling the transportation of cesium source devices; decommissioning cesium devices requires government approval that historically has required a prolonged period (months) for approvals; and disposing of the source is also problematic.
In addition, prior to decommissioning a cesium source irradiator, the new irradiator would have to be installed and validated. Space within most establishments is at a premium with very little to spare for installation of a new irradiator. If the irradiator is an X-ray device, facility modifications would have to be made before installation (i.e., water cooling systems are required for some devices). Once the device is installed, the manufacture would have to validate and perform dose mapping prior to its use. A requirement for mass replacement would create a tremendous burden on the manufacturers, with limited resources, to accomplish the required procedures.
Besides the manufacturer burden, the present medical reimbursement mechanism does not provide blood establishments with a means to recover any costs associated with a switch out of cesium source irradiators – expenditures for the equipment, installation, training, and any facility modifications required. Establishments budget years in advance – based on knowledge of the half-life of the cesium-137 source – in order to afford new equipment at the appropriate time. Since blood establishments are uniformly nonprofit, they rarely have significant economic reserves. The current economic status of blood establishments necessitate that the Federal Government provides economic relief for this endeavor, in excess of $250,000 per irradiator.
The Off-Site Source Recovery Project (OSRP), a US Government activity sponsored by the National Nuclear Security Administration's (NNSA) Office of Global Threat Reduction, is responsible for the removal of excess, unwanted, abandoned, or orphan radioactive sealed sources. However, it is our understanding that the funding and capacity of this organization is not sufficient to accommodate all of the cesium source irradiators currently in use. If establishments are mandated to decommission their cesium source irradiators within a specified period of time, additional funding and resources must be provided to OSRP or a mechanism and funding to reimburse an establishment must be implemented.
In conclusion, we recommend that the continued use of cesium source irradiators for irradiating blood components be permitted, but with modifications to ensure greater security of the source. Available alternatives are potentially less reliable (mechanical issues and decreased throughput) and may result in delay in providing patient therapy. The economic impact on current blood community licensees will be significant if cesium source irradiators are banned. The recent NRC publication (RIS 2008-17) outlined additional validated steps that can be taken to further restrict access to cesium irradiator sources. The NRC should first take time to evaluate the effectiveness of these measures before initiating further recommendations or rulemaking. However, if cesium source irradiators are to be phased out, then Federal Government funding to defray the cost of converting technologies must be made available.