Low dose radiation therapy for COVID-19: Effective dose and estimation of cancer risk.

Autor: García-Hernández T; Department of Medical Physics, ERESA, Hospital General Universitario, Valencia, Spain. Electronic address: mtrinitat.movil@gmail.com., Romero-Expósito M; Área de Ciencias Básicas y Ambientales, Instituto Tecnológico de Santo Domingo (INTEC), P.O. Box 342-9/249-2, Santo Domingo, Dominican Republic., Sánchez-Nieto B; Instituto de Física, Pontificia Universidad Católica de Chile, Santiago, Chile.
Jazyk: angličtina
Zdroj: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology [Radiother Oncol] 2020 Dec; Vol. 153, pp. 289-295. Date of Electronic Publication: 2020 Oct 14.
DOI: 10.1016/j.radonc.2020.09.051
Abstrakt: Background and Purpose: The objective of this work is to evaluate the risk of carcinogenesis of low dose ionizing radiation therapy (LDRT), for treatment of immune-related pneumonia following COVID-19 infection, through the estimation of effective dose and the lifetime attributable risk of cancer (LAR).
Material and Methods: LDRT treatment was planned in male and female computational phantoms. Equivalent doses in organs were estimated using both treatment planning system calculations and a peripheral dose model (based on ionization chamber measurements). Skin dose was estimated using radiochromic films. Later, effective dose and LAR were calculated following radiation protection procedures.
Results: Equivalent doses to organs per unit of prescription dose range from 10 mSv/cGy to 0.0051 mSv/cGy. Effective doses range from 204 mSv to 426 mSv, for prescription doses ranging from 50 cGy to 100 cGy. Total LAR for a prescription dose of 50 cGy ranges from 1.7 to 0.29% for male and from 4.9 to 0.54% for female, for ages ranging from 20 to 80 years old.
Conclusions: The organs that mainly contribute to risk are lung and breast. Risk for out-of-field organs is low, less than 0.06 cases per 10000. Female LAR is on average 2.2 times that of a male of the same age. Effective doses are of the same order of magnitude as the higher-dose interventional radiology techniques. For a 60 year-old male, LAR is 8 times that from a cardiac CT, when prescription dose is 50 cGy.
(Copyright © 2020 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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