A deployable in vivo EPR tooth dosimeter for triage after a radiation event involving large populations

Abstract

In order to meet the potential need for emergency large-scale retrospective radiation biodosimetry following an accident or attack, we have developed instrumentation and methodology for in vivo electron paramagnetic resonance spectroscopy to quantify concentrations of radiation-induced radicals within intact teeth. This technique has several very desirable characteristics for triage, including independence from confounding biologic factors, a non-invasive measurement procedure, the capability to make measurements at any time after the event, suitability for use by non-expert operators at the site of an event, and the ability to provide immediate estimates of individual doses. Throughout development there has been a particular focus on the need for a deployable system, including instrumental requirements for transport and field use, the need for high throughput, and use by minimally trained operators. Numerous measurements have been performed using this system in clinical and other non-laboratory settings, including in vivo measurements with unexposed populations as well as patients undergoing radiation therapies. The collection and analyses of sets of three serially-acquired spectra with independent placements of the resonator, in a data collection process lasting approximately five minutes, provides dose estimates with standard errors of prediction of approximately 1 Gy. As an example, measurements were performed on incisor teeth of subjects who had either received no irradiation or 2 Gy total body irradiation for prior bone marrow transplantation; this exercise provided a direct and challenging test of our capability to identify subjects who would be in need of acute medical care.

In-Vivo Radiation Dosimetry Using Portable L Band Epr: On-Site Measurement of Volunteers in Fukushima Prefecture, Japan

“…The experimental procedures for in vivo measurements including subject immobilization, resonator positioning, and instrumental settings as described in our publications (8,10,14,15) . Spectra are acquired with a nominal modulation amplitude of 0.4 mT and an incident microwave power of 50 mW.…”

Evaluating the Special Needs of The Military for Radiation Biodosimetry for Tactical Warfare Against Deployed Troops

“…In contrast to biologically-based markers, physically-based changes in tissues directly reflect the physical consequences of absorbing ionizing radiation in tissues. The strengths of physically-based methods (Desrosiers and Schauer 2001, He et al 2014, Wilcox et al 2010; Williams et al 2011 and 2014; Prasanna et al 2010a) include that they are insensitive to concomitant injury such as trauma or burns and to stress. The detectable changes happen almost instantaneously and persist for a long time.…”

Advances in a framework to compare bio-dosimetry methods for triage in large-scale radiation events

“…Time to emesis (EMESIS) 10 min to 4 h (27 -31) accurate recall: 48 h to .10 d ,5 min Micronucleus (CBMN) 0 to 1 d (24,32) Year (33) 4 to 6 d Gamma (H2AX) 3 to 30 min (7,34,35) 1 to 48 h (7,11,34,35) 1 to 2 d EPR in vivo tooth (EPR) 0 (17,36) Lifetime (17,37,38) ,10 min Gene expression 24 h (20) Variable by type (20) 2.5 to 17 d a W3 ¼ total processing times across five process steps; Table 2 presents references and details about the five steps.…”