The Impact of Time on Decorporation Efficacy After a “Dirty Bomb” Attack Studied by Simulation

Abstract

In the case of a nuclear or radiological incident, there is a risk of external and internal contamination with radionuclides in addition to external irradiation. There is no consensus whether decorporation treatment should be initiated right away on spec or pending the results of internal dosimetry to determine the indication. Based on biokinetic models for plutonium-239, americium-241 and cesium-137, the efficacy of a decorporation treatment using DTPA or Prussian blue was simulated depending on the initiation time and the duration of treatment for different invasion pathways and physicochemical properties of the inhaled compounds. For the same level of radioactivity incorporated, the committed effective dose increases with the speed of the invasion process. The impact of the initiation time of a decorporation treatment is particularly important when the absorption of the radionuclide is fast. Even if started early after incorporation, the therapeutic efficacy is less for americium-241 or cesium-137 compared to plutonium-239. Therapeutic efficacy increases with treatment duration up to about 90 days for plutonium-239 and cesium-137, whereas a prolongation of the treatment over this limit may further enhance efficacy in the case of americium-241. In the case of a nuclear incident, several fractions with different but a priori unknown physicochemical properties may be inhaled. Thus, decorporation therapy should be started as soon as possible after the incorporation of the radionuclide(s), as a loss of efficacy caused by a delay of treatment initiation possibly cannot be compensated later on. Treatment should be pursued for several months.

Benefit-Cost Analysis of Radiocesium Decorporation by a Prussian Blue Treatment and Stockpiling

“…That is why for the loss of life expectancy, and conversely for the life time saved by the medical treatment, we used for our computations the average population value (0.42 day/mSv) [21]. The commited effective dose depends on the nature of the radionuclide(s), the physicochemical properties of the compounds, the route of entry (inhalation, ingestion) and the incorporated radioactivity [15]. Thus, these factors also influences the economic assessment of a decorporation treatment, besides the medical effectiveness and the costs of the administered therapy.…”

“…The medical effectiveness of a decorporation treatment using Prussian Blue (PB) after incorporation of radioactive cesium-137 by acute inhalation, as expected for victims of a "dirty bomb" attack, was studied by simulation in previous studies [14,15]. Simulations were based on the biokinetic model for cesium developed by the ICRP.…”

“…It was assumed that decorporation treatment was started 1 day or 180 days after incorporation and continued for 90 days, when medical effectiveness reaches a plateau [15]. Benefits and costs were analyzed for different delays between the initial establishment of the stockpile and the "dirty bomb" attack, i.e.…”

“…The medical effectiveness improves steeply with the duration of the treatment up to about 90 days to approach a plateau in the further course [15], and as a consequence, so does the monetary benefits independently on the VSL chosen and discounting. Our findings also show that if holding costs are not explicitly considered including the time frame of storage, a PB decorporation treatment is cost-effective even if it is started as late as 90 days after incorporation and the lower VSL of 1.646 million € is used and discounted.…”

Medical management of victims contaminated with radionuclides after a “dirty bomb” attack

“…In the case of plutonium-239, (Ca)DTPA treatment is highly effective if started early (Fig. 5 ) [ 45 ]. If treatment is delayed, the decrease in therapeutic effectiveness is particularly rapid if the invasion kinetic of plutonium is fast.…”