Radiation and Terrorism - Are We Ready?

By Peter Emauel, M.D.
Yes, there is the horror of planes being used as weap-ons. And there is the real threat of biological weapons including anthrax, small pox, and the like. But the nuclear threat also looms largely in this day and age of terror. Based on our expertise, we as hematologists may very well be expected to serve a significant role in evaluating and treating victims of mass accidental or deliberate exposure to radiation.

The Educational Session entitled The Hematologist and Radiation Casualties is thus unique to the ASH meeting and also timely in today’s climate. The session will be offered twice, today from 4:15 p.m. – 6:00 p.m., and Sunday from 9:45 a.m. – 11:30 a.m. All indicators would say that this session promises to be an exciting education for all hematologists, from those fresh out of fellowship, to those who are nearing or beyond retirement. In few other venues will you find such a group of experts discussing the specific hematologic effects of exposure to atomic weapons.

Dr. Dainiak will discuss two different sections dealing with radiation injury. In the first section he will review the four components of the Acute Radiation Syndrome – hematopoietic, neurovascular, gastrointestinal, and cutaneous subsyndromes. Can everyone recite the definitions of a Rad, a Gray, a Rem, a Sievert, and a Becquerel? He will cover this for us. He will present the multitude of clinical signs and symptoms that radiation injury patients can demonstrate through the entire course from the initial presentation (the prodromal phase) and on through the remaining course of the disease (the manifest illness). The hematopoietic component includes four grades of hematopoietic response to radiation in humans. In the second section he will teach us clinical and laboratory methods in order to assess radiation dosage received by the victim. This includes time to onset as well as severity of vomiting, rate of decline in absolute lymphocyte counts, and the appearance of chromosomal aberrations.

The Acute Radiation Medical Management Working Group for the Strategic National Stockpile Program has developed a consensus opinion for these areas. Dr. Dainiak will present this consensus opinion in the setting of potential dispersal scenarios, assessment of radiation dose, cellular effects, and clinical assessment and early triage.

Following this stimulating discussion, we will next move to Dr. Waselenko who will discuss the specific management of the hematopoietic syndrome of radiation injury. This will include discussion of the potential effects at varying doses of partial-body or whole-body radiation exposures from > 1 Gray; to 2-3 Gray; to 3-7 Gray; and on up to those individuals receiving as much as 10 Gray exposure.

The appropriate use of cytokines, and which cytokine, and the length of cytokine therapy will be covered by Dr. Waselenko. Results of both pre-clinical and clinical studies in this area will be summarized. Essentials of supportive care will also be discussed at length. These are, most assuredly, not your simple, AML post-chemotherapy patients. When should potassium iodide be used and how should it be administered? Come and learn.

Dr. Armitage will then discuss the role of stem cell transplantation in victims with bone marrow failure. Who should get it and when? Is the “window” for appropriate stem cell transplantation only for those victims with 7-10 Gray exposure? Are there unique barriers to transplantation in these victims that we are unaccustomed to in typical transplant recipients? Finally, Dr. MacVittie will give us a glimpse of new directions in growth factor therapy, including therapy for lymphopenia and immunosuppression, and also therapy for immune reconstitution. All in all, this promises to be an exciting and fresh type of educational experience for ASH attendees, certainly one that should be experienced first-hand rather than casually read over during the plane ride home.