Assessment and clinical management of internal contamination

Abstract

Internal contamination by radionuclides may occur through inhalation, ingestion and absorption through the skin or subcutaneous tissue. The clinical management of internalized radionuclides requires integration of clinical signs and symptoms with dose estimates in biological tissues obtained from the face, nose, sputum, urine, feces and/or skin. Assessment of ingested radionuclides includes bioassays of urine and feces, and if available, whole body counting for radionuclides that emit penetrating x-rays or gamma-rays. An estimate of intake dose may be made at the time of initial patient evaluation by measuring radioactivity, converting counts/minute to depositions/minute with a specific gamma-ray constant, and comparing the amount to its annual limit on intake, clinical decision guide or derived reference level. Since no one dies from internal contamination per se, medically unstable patients should be stabilized before addressing internal contamination. Whenever possible, internal contaminants should be physically removed as soon as possible after exposure. For inhaled internal contaminants, radionuclide-specific therapy may include administration of an ion exchange resin (i.e., Prussian blue, PB) or chelating agent (i.e., diethylenetriamine pentaacetate, DTPA, that binds to radioactive plutonium, americium, and curium), or physical removal of insoluble particles having a high activity radionuclide (192Ir, 90Sr, 210Po) by bronchioalveolar lavage. Decorporation with PB, DTPA and other agents is used to enhance excretion. Treatment of wounds contaminated with an actinide includes gentle irrigation, surgical excision of contaminated tissue and DTPA. The averted dose (i.e., the total effective dose averted by therapy) may be calculated for each exposure route.

Radioprotectors, Radiomitigators, and Radiosensitizers

“…Nplate ® (romiplostim) for injection, for subcutaneous use). Except for romiplostim, they have all been used to treat radiation accident victims with beneficial results [118][119][120][121].…”

Synthesis, Characterization and Application of DTPA-Modified Chitosan Hydrogel Dressing for Early Decontamination of Radioactive Contamination in Wounds

“…For wounds contaminated with rare earth elements, such as plutonium or transplutonium elements, a calcium-DTPA solution is required for decontamination. 41 In the present study, we designed and prepared a chitosanbased wound dressing with multiple functions, including broad-spectrum chelation, wound protection, anti-inflammation, wound healing promotion and biocompatibility properties. In particular, we synthesized methacrylated chitosan (CSMA) by reacting chitosan with methacrylic anhydride, followed by graft modification with the broad-spectrum chelating agent DTPA to prepare a DTPA-modified CSMA photocurable (CSMA-g-DTPA) hydrogel dressing.…”

“…For strontium decontamination, the efficacy of DTPA has been documented, , and it can chelate the congener elements of strontium, such as barium and calcium. For wounds contaminated with rare earth elements, such as plutonium or transplutonium elements, a calcium-DTPA solution is required for decontamination …”

A 3D In Vitro Cortical Tissue Model Based on Dense Collagen to Study the Effects of Gamma Radiation on Neuronal Function

“…[ 2–4 ] Most IR‐induced injury studies have addressed one or more of the following systems/tissues: bone marrow, gastrointestinal tract, lungs, skin, vasculature, and kidneys. [ 5–8 ] However, IR, including GR, is also associated with radiation‐induced cognitive decline (RICD) [ 9 ] ; likely attributable to disruption of “healthy” neuronal network function.…”