Marcos de Lima, MD

2009-11-01

Have you ever thought about what you could do as a hematologist, should an improvised nuclear device explode in our country? Contrary to the common first answer (i.e., very little), there is actually a lot we can do.

I represented the American Society of Hematology (ASH) at the National Public Health and Healthcare Radiological/Nuclear Scarce Resources Allocation Workshop, held this past June. It was organized by the Department of Health and Human Service (HHS) Office of Preparedness and Emergency Operations (OPEO). The main goal was to generate and obtain support and endorsement for a series of manuscripts that will provide information for triage and other decisions pertaining to a nuclear terrorist attack. The Office of the Assistant Secretary for Preparedness and Response (Health and Human Services) was also seeking to create a system for information updates on new developments in medical countermeasures and treatments, as well as on physical injury outcomes and other related topics.

Also represented at the meeting was the Radiation Injury Treatment Network (RITN), a cooperative endeavor of the National Marrow Donor Program (NMDP) and the American Society for Blood and Marrow Transplantation (ASBMT). This group is composed of transplant and donor centers and cord blood banks, and because participating centers may be asked to admit radiation victims, RITN has developed treatment guidelines and educational initiatives and has also assisted participating centers in developing response plans and providing for coordination of response. In addition, RITN and the NMDP/ASBMT have developed a data collection protocol to be used prospectively should a marrow-toxic event occur.

The possibility that terrorists may use radioactive elements as a means to bring chaos and suffering has brought radiation to a “center stage” not seen since the end of the Cold War. The number of casualties would depend, of course, on the type of event, such as a radiologic dispersal device (“dirty bomb”) or an improvised nuclear device. The number of victims could range from very few to more than a million, and most experts put such a terrorist act as one of the major threats to our national security. Most anticipated scenarios involve an event in one area, for which the resources of the rest of the country would be mobilized, leading to a large-scale, collaborative effort by several members of society as a whole and the medical community in particular.

Hematologists and oncologists are in a key position to participate in these discussions, given our experience with cytopenic patients; it is expected that the general care of patients with radiation-induced marrow toxicity should be familiar to those of us involved in the treatment of pancytopenic patients. Hematopoietic stem cell transplantation is expected to be the exception and not the rule for treating acute radiation syndrome, but patients exposed to higher doses of radiation and with irreversible damage to hematopoietic stem cells should be considered for this treatment modality, as reviewed elsewhere.^1-5 Victims are likely to have multi-system injuries (burns, general trauma care, etc.), and a multidisciplinary approach will be required.

Adequate triage and risk assessment will depend on proper estimates of absorbed radiation dose. Geographic location of patients in relation to the blast, time to emesis, blood counts, and lymphocyte and platelet depletion rates are some of the clinical variables that may help estimate absorbed dose. The current state-of-the art evaluation method is assessment of dicentric chromosomes in circulating lymphocytes, an assay that is logistically demanding.

The meeting also dealt with the complex issue of ethics in triage and the important topic of education of health-care workers. Opportunities for research support in several aspects of preparedness are available and are reviewed elsewhere.5 Finally, all hospitals have disaster plans in place for various possible scenarios. As I familiarized myself with my institution’s plans, I’ve been surprised by how much does exist; by reviewing the institutional plan, hematologists can visualize their role, should disaster strike. The hematologist is unlikely to be a first responder in the field. Trauma experts and other specialists are more suitable for that role. However, expertise in our area will be invaluable once the trauma is addressed. Although training is probably the key element in our preparedness, I believe the first step is awareness that this is a problem that could strike literally “close to the heart,” and, therefore, be OUR problem.

1. Waselenko JK, MacVittie TJ, Blakely WF, et al. Medical management of the acute radiation syndrome: Recommendations of the Strategic National Stockpile Radiation Working Group. Ann Intern Med. 2004;140:1037-51.
2. Radiation Injury Treatment Network. Acute Radiation Syndrome Treatment Guidelines. http://www.nmdp.org/RITN/index.html/guidelines/docs/ars_treatment_guide1.pdf.
3. Fliedner TM, Chao NJ, Bader JL, et al. Stem cells, multi-organ failure in radiation emergency medical preparedness: a U.S./European consultation workshop. Stem Cells 2009; 27:1205-11.
4. Fliedner TM, Graessle D, Meineke V, Dörr H. Pathophysiological principles underlying the blood cell concentration responses used to assess the severity of effect after accidental whole-body radiation exposure: an essential basis for an evidence-based clinical triage. Exp Hematol. 2009;144:2619-22.
5. Weinstock DM, Case Jr. C, Bader JL, et al. Radiologic and nuclear events: contingency planning for hematologists/oncologists. Blood. 2008;111:5440-45.
6. Friesecke I, Beyrer K, Fliedner TM. How to cope with radiation accidents: the medical management. Br J Radiol. 2001;74:121-22.

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