Cumulative doses from computed tomography 2014-2017
Descriptive analysis of a population at the Clínicas Hospital
Abstract
Introduction and objective: the rising use of computed tomography results in an increase in the collective doses with the potential risk for ionizing radiation. The study aimed at determining the frequency of repeated scans and at estimating the cumulative radiation doses between 2014 and 2017 in a sample of patients seen during July/August of 2017 at the Clinicas Hospital.
Method: patients who consulted at the Imagenology Department of the Clinicas Hospital in July and August, 2017 whose treating physician indicated a computed tomography were included in the study. It consisted of a descriptive, longitudinal, retrospective study. A spread sheet with demographic data and procedure was filled out and previous tomographic studies were looked for in the medical images file system, and reports issued in the last 3 years were analysed.
Results: 110 patients made up the sample; more than one tomography was performed to 59 (54.1%) patients underwent more than one scan, abdominal and pelvic scans being the most frequent. 7 patients (6.4%) surpassed the 100 mSv dose threshold and 16 (14.5%) received doses between 50 and 100 mSv. Likewise, 23 patients (20.9%) underwent more than 4 tomographies, that is more than one per year.
Conclusions:computed tomography is a beneficious diagnostic tool, provided it is used rationally upon a risk/benefit balance analysis. Awareness needs to be raised in relation to the risks associated to cumulative doses from multiple scans
References
(1) Canadian Nuclear Safety Commission. Introduction to Radiation. Ottawa: CNSC, 2012. Disponible en:http://nuclearsafety.gc.ca/eng/pdfs/Reading-Room/radiation/Introduction-to-Radiation-eng.pdf. Consulta: octubre 2017.
(2) Kalra MK, Sodickson AD, Mayo-Smith WW. CT radiation: key concepts for gentle and wise use. RadioGraphics 2015; 35(6):1706-21. Disponible en: http://pubs.rsna.org/doi/10.1148/rg.2015150118. Consulta: setiembre 2017.
(3) Mettler FA Jr, Bhargavan M, Faulkner K, Gilley DB, Gray JE, Ibbott GS, et al. Radiologic and nuclear medicine studies in the United States and worldwide: frequency, radiation dose, and comparison with other radiation sources-1950-2007. Radiology 2009; 253(2):520-31. Disponible en: http://pubs.rsna.org/doi/10.1148/radiol.2532082010. Consulta: setiembre 2017.
(4) Hendee WR, O'Connor MK. Radiation risks of medical imaging: separating fact from fantasy. Radiology 2012; 264(2):312-21. doi:10.1148/radiol. 12112678.
(5) Brenner DJ, Hall EJ. Computed tomography-an increasing source of radiation exposure. N Engl J Med 2007; 357(22):2277-84. Disponible en: http://www.nejm.org/doi/full/10.1056/NEJMra072149. Consulta: julio 2017.
(6) Griffey RT, Sodickson A. Cumulative radiation exposure and cancer risk estimates in emergency department patients undergoing repeat or multiple CT. AJR Am J Roentgenol 2009; 192(4):887-92. doi:10.2214/AJR.08.1351.
(7) Hricak H, Brenner DJ, Adelstein SJ, Frush DP, Hall EJ, Howell RW, et al. Managing radiation use in medical imaging: a multifaceted challenge. Radiology 2011; 258(3):889-905. Disponible en: http://pubs.rsna.org/doi/10.1148/radiol.10101157. Consulta: setiembre 2017.
(8) Shah KH, Slovis BH, Runde D, Godbout B, Newman DH, Lee J. Radiation exposure among patients with the highest CT scan utilization in the emergency department. Emerg Radiol 2013; 20(6):485-91. Disponible en: http://link.springer.com/10.1007/s10140-013-1142-8. Consulta: setiembre 2017.
(9) Lam DL, Larson DB, Eisenberg JD, Forman HP, Lee CI. Communicating potential radiation-induced cancer risks from medical imaging directly to patients. AJR Am J Roentgenol 2015; 205(5):962-70. Disponible en: http://www.ajronline.org/doi/10.2214/AJR.15.15057. Consulta: setiembre 2017.
(10) Lee CI, Haims AH, Monico EP, Brink JA, Forman HP. Diagnostic CT scans: assessment of patient, physician, and radiologist awareness of radiation dose and possible risks. Radiology 2004; 231(2):393-8. Disponible en: http://pubs.rsna.org/doi/10.1148/radiol.2312030767. Consulta: setiembre 2017.
(11) Ubeda de la Cerda C, Nocetti D, Alarcon R, Insulza A, Calcagno S, Castro M, et al. Magnitudes y unidades para dosimetría a pacientes en radiodiagnóstico e intervencionismo. Rev Chil Radiol 2015; 21(3):94-9. Disponible en: https://scielo.conicyt.cl/pdf/rchradiol/v21n3/ art04.pdf. Consulta: setiembre 2017.
(12) Andisco D, Blanco S, Buzzi AE. Dosimetría en tomografía computada. Rev Argent Radiol 2014; 78(3):156-60. doi:10.1016/j.rard.2014.07.004.
(13) Mendizábal Méndez AL. Radiación ionizante en tomografía computada: un tema de reflexión. An Radiol Méx 2012; 2:90-7. Disponible en: http://www.medigraphic.com/pdfs/anaradmex/arm-2012/arm122d.pdf. Consulta: setiembre 2017.
(14) Slovis BH, Shah KH, Yeh DD, Seethala R, Kaafarani HM, Eikermann M, et al. Significant but reasonable radiation exposure from computed tomography-related medical imaging in the ICU. Emerg Radiol 2016; 23(2):141-6. Disponible en: http://link.springer.com/10.1007/s10140-015-1373-y. Consulta: setiembre 2017.
(15) Sodickson A, Baeyens PF, Andriole KP, Prevedello LM, Nawfel RD, Hanson R, et al. Recurrent CT, cumulative radiation exposure, and associated radiation-induced cancer risks from CT of adults. Radiology 2009; 251(1):175-84. Disponible en: http://pubs.rsna.org/doi/10.1148/radiol. 2511081296. Consulta: setiembre 2017.
(16) Schonfeld SJ, Lee C, Berrington de González A. Medical exposure to radiation and thyroid cancer. Clin Oncol (R Coll Radiol) 2011; 23(4):244-50. doi:10.1016/j.clon.2011.01.159.
(17) Comisión Chilena de Energía Nuclear; Vivallo L, Villanueva L, Sanhueza S, comps. Efectos de las radiaciones ionizantes en el ser humano. Santiago: CCHEN, 2010: 38 p. Disponible en: http://oirs.cchen.cl/saber/PDF/efectos_biologicos_mayo2010.pdf. Consulta: setiembre 2017.
(18) Smith G. UNSCEAR 2013 Report. Vol I: Report to the General Assembly, Annex A: Levels and effects of radiation exposure due to the nuclear accident after the 2011 great east-Japan earthquake and tsunami. United Nations Scientific Committee on the Effects of Atomic Radiation New York: United Nations (2014). Book Review) J Radiol Prot 2014; 34:725-7. Disponible en: http://iopscience.iop.org/article/10.1088/0952-4746/34/3/B01/pdf. Consulta: setiembre 2017.
(19) Ozasa K, Shimizu Y, Suyama A, Kasagi F, Soda M, Grant EJ, et al. Studies of the mortality of atomic bomb survivors, Report 14, 1950-2003: an overview of cancer and noncancer diseases. Radiat Res 2012; 177(3):229-43. Disponible en: http://www.bioone.org/doi/10.1667/RR2629.1. Consulta: setiembre 2017.
(20) Pierce DA, Preston DL. Radiation-related cancer risks at low doses among atomic bomb survivors. Radiat Res 2000; 154(2):178-86. doi: 10.1667/0033-7587(2000)154 0178:RRCRAL2.0.CO;2.
(21) Preston DL, Shimizu Y, Pierce DA, Suyama A, Mabuchi K. Studies of mortality of atomic bomb survivors. Report 13: solid cancer and noncancer disease mortality: 1950-1997. Radiat Res 2003; 160(4):381-407. Disponible en: http://www.bioone.org/doi/10.1667/0033-7587%282000%29154%5B0178%3ARRCRAL%5D2.0.CO%3B2. Consulta: setiembre 2017.
(22) Shimizu Y, Pierce DA, Preston DL, Mabuchi K. Studies of the mortality of atomic bomb survivors. Report 12, part II. Noncancer mortality: 1950-1990. Radiat Res 1999; 152(4):374-89. Disponible en: http://www.rrjournal.org/doi/pdf/10.2307/3580222. Consulta: setiembre 2017.
(23) Pierce DA, Shimizu Y, Preston DL, Vaeth M, Mabuchi K. Studies of the mortality of atomic bomb survivors. Report 12, Part I. Cancer: 1950-1990. Radiat Res 2012; 178(2):AV61-AV87. Disponible en: http://www.bioone.org/doi/10.1667/RRAV06.1. Consulta: setiembre 2017.
(24) Pearce MS, Salotti JA, Little MP, McHugh K, Lee C, Kim KP, et al. Radiation exposure from CT scans in childhood and subsequent risk of leukaemia and brain tumours: a retrospective cohort study. Lancet 2012; 380(9840):499-505. Disponible en: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)60815-0/fulltext. Consulta: setiembre 2017.
(25) National Research Council. Health risks from exposure to low levels of ionizing radiation: BEIR VII Phase 2. Washington, DC: The National Academies, 2006. doi:10.17226/11340.
(26) Huda W, Ogden KM, Khorasani MR. Converting dose-length product to effective dose at CT. Radiology 2008; 248(3):995-1003. doi:10.1148/radiol.2483071964.
(27) Uruguay. UdelaR, Facultad de Medicina. Hospital de Clínicas, Dr. Manuel Quintela. Indicadores hospitalarios. Montevideo: 2016. Disponible en: http://www.hc.edu.uy/index.php/conozca-el-hc/indicadores. Consulta: octubre 2017.
(28) Brenner DJ, Doll R, Goodhead DT, Hall EJ, Land CE, Little JB, et al. Cancer risks attributable to low doses of ionizing radiation: assessing what we really know. Proc Natl Acad Sci USA 2003; 100(24):13761-6. Disponible en: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC283495/. Consulta: octubre 2017.
(29) Einstein AJ. Medical imaging: the radiation issue. Nat Rev Cardiol 2009; 6(6):436-8. Disponible en: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684954/. Consulta: octubre 2017.
(30) Sociedad Argentina de Radiología, coord. Guía de recomendaciones para la correcta solicitud de pruebas de Diagnóstico por Imagen. Disponible en: http://www.aac.org.ar/imagenes/guias/guia_solic_diag_x_imagenes.pdf. Consulta: octubre 2017.
(31) Kanal KM, Butler PF, Sengupta D, Bhargavan-Chatfield M, Coombs LP, Morin RL. U.S. diagnostic reference levels and achievable doses for 10 adult CT examinations. Radiology 2017; 284(1):120-33. doi:10.1148/radiol.2017161911.
(32) Directives: Council Directive 2013/59/EURATOM of 5 december 2013. OJEU 2014; L13(57):1-73.
