title: Performance comparison of two Olympus InnovX handheld x-ray analyzers for feasibility of measuring arsenic in skin in vivo - Alpha and Delta models.
abstract: The Figure-Of-Merit (FOM) performance, a combination of detection limit and dose, is compared between two generations of handheld X-Ray Fluorescence (XRF) spectrometers for the feasibility of in vivo XRF measurement of arsenic (As) in skin. The Olympus InnovX Delta model analyzer (40 kVp using either 37 or 17μA) was found to show improvements in Minimum Detection Limit (MDL) using arsenic As-doped skin calibration phantoms with bulk tissue backing, when compared to the first generation InnovX Alpha model (40kVp, 20μA) in 120s measurements. Differences between two different definitions of MDL are discussed. On the Delta system, an MDL of (0.462±0.002) μg/g As was found in phantoms, with a nylon backing behind to mimic bulk tissue behind skin. The equivalent and effective doses were found to be (10±2) mSv and ~7×10-3μSv respectively for the Alpha and (15±4) mSv and ~8×10-3μSv respectively for the Delta system in 120s exposures. Combining MDL and effective dose, a lower (better) FOM was found for the Delta, (1.7±0.4) ppm mSv1/2, compared to (4.4±0.5) ppm mSv1/2for the Alpha model system. The Delta analyzer demonstrates improved overall system performance for a rapid 2-min measurement in As skin phantoms, such that it can be considered for use in populations exposed to arsenic.
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, Canada L8S 4K1. Electronic address: elstan.desouza@gmail.com.
authors.forename: E D
authors.initials: ED
authors.lastname: Desouza
authors.affiliation: Department of Physics, California State University, Fresno, CA 93740-8031, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Gherase
authors.affiliation: Department of Physics, Mount Allison University, Sackville, NB Canada E4L 1E6.
authors.forename: D E B
authors.initials: DE
authors.lastname: Fleming
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, Canada L8S 4K1.
authors.forename: D R
authors.initials: DR
authors.lastname: Chettle
authors.affiliation: Department of Physics, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: J M
authors.initials: JM
authors.lastname: O'Meara
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, Canada L8S 4K1.
authors.forename: F E
authors.initials: FE
authors.lastname: McNeill
mesh_terms: D001151:Arsenic / Q000032:analysis*; D002138:Calibration; D004784:Environmental Monitoring / Q000295:instrumentation / Q000706:statistics & numerical data; D004785:Environmental Pollutants / Q000032:analysis; D005240:Feasibility Studies; D006801:Humans; D057230:Limit of Detection; D019047:Phantoms, Imaging; D012867:Skin / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission / Q000295:instrumentation* / Q000706:statistics & numerical data
chemical_list: D004785:Environmental Pollutants; D001151:Arsenic
keywords: Arsenic; Minimum detection limit; Portable XRF; Radiation dose; Scattered photons