Determining the Fetal Dose in Ventilation/Perfusion Scan Using Monte Carlo Simulation

Document Type : Original Article (s)

Authors

1 MSc Student, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 Professor, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Background: Pulmonary embolism (PE) is a blockage in one of the pulmonary arteries. Ventilation/Perfusion (V/Q) scan is one the diagnostic methods of PE in pregnant women. It is necessary to investigate fetal dose and compare it with recommended values. The aim of this study was to determine the fetal dose in V/Q scan using Monte Carlo simulation.Methods: An adult pregnant woman phantom and all her displaced organs were used for simulation. Source organs were defined for each of the radiopharmaceuticals used in two lung ventilation and perfusion scans, including lung and bladder for 133Xe, 81mKr, and technetium diethylene-triamine-pentaacetate aerosol (99mTc-DTPA-aerosol) for lung ventilation scan, and lung, bladder, and liver for 99mTc-technetium macroaggregated albumin (MAA) for lung perfusion scan. Fetal dose was determined and evaluated using the simulation output after calculations.Findings: For 99mTc-MAA at prescription dose of 200 MBq, fetal dose was found to be 1.01 mGy, maximum fetal dose was 1.97 mGy, and both of them were more than the values recommended by International Commission on Radiological Protection (ICRP). For 99mTc-DTPA, fetal and maximum doses were below 1 mGy, and for 133Xe and 81mKr, fetal dose was negligible.Conclusion: It is concluded that considering higher dose to the fetus (200 MBq of 99mTc-MAA), if the pregnant woman scan is needed, her awareness must be done.

Keywords

References

  1. Bourjeily G, Paidas M, Khalil H, Rosene-Montella K, Rodger M. Pulmonary embolism in pregnancy. Lancet 2010; 375(9713): 500-12.
  2. Stone SE, Morris TA. Pulmonary embolism and pregnancy. Crit Care Clin 2004; 20(4): 661-77.
  3. Bajc M, Olsson B, Gottsater A, Hindorf C, Jogi J. V/P SPECT as a diagnostic tool for pregnant women with suspected pulmonary embolism. Eur J Nucl Med Mol Imaging 2015; 42(8): 1325-30.
  4. Konstantinides SV, Torbicki A, Agnelli G, Danchin N, Fitzmaurice D, Galie N, et al. 2014 ESC guidelines on the diagnosis and management of acute pulmonary embolism. Eur Heart J 2014; 35(43): 3033-3069k.
  5. Brent RL, Beckman DA, Jensh RP. Relative radiosensitivity of fetal tissues. In: Lett JT, Altman KI, editors. Advances in radiation biology relative radiation sensitivities of human organ systems. 12th ed. San Diego, CA: Academic Press; 1987. p. 239-56.
  6. Sitharama SA, Jindal B, Vuriti MK, Naredi BK, Krishnamurthy S, Subramania DB. Fetus in fetu: Case report and brief review of literature on embryologic origin, clinical presentation, imaging and differential diagnosis. Pol J Radiol 2017; 82: 46-9.
  7. Sadler TW, Langman J. Langman's medical embryology. Philadelphia, PA: Lippincott Williams and Wilkins; 2011.
  8. Gomes M, Matias A, Macedo F. Risks to the fetus from diagnostic imaging during pregnancy: review and proposal of a clinical protocol. Pediatr Radiol 2015; 45(13): 1916-29.
  9. Xu XG, Eckerman KF. Handbook of anatomical models for radiation dosimetry. Boca Raton, FL: CRC Press; 2009.
  10. Hurwitz LM, Yoshizumi T, Reiman RE, Goodman PC, Paulson EK, Frush DP, et al. Radiation dose to the fetus from body MDCT during early gestation. AJR Am J Roentgenol 2006; 186(3): 871-6.
  11. Russell JR, Stabin MG, Sparks RB, Watson E. Radiation absorbed dose to the embryo/fetus from radiopharmaceuticals. Health Phys 1997; 73(5): 756-69.
  12. Cook JV, Kyriou J. Radiation from CT and perfusion scanning in pregnancy. BMJ 2005; 331(7512): 350.
  13. Haramati LB, Patel VK, Freeman LM, Thacker P, Lee EY. Acute pulmonary embolism in adults and children: evidence-based emergency imaging, evaluation, and diagnosis. In: Kelly A, Cronin P, Puig S, Applegate KE, editors. Evidence-based emergency imaging: optimizing diagnostic imaging of patients in the emergency care setting. Cham, Switzerland: Springer International Publishing; 2018. p. 227-45.
  14. Papadakis GZ, Karantanas AH, Perisinakis K. "Pulmonary embolism diagnostics of pregnant patients: What is the recommended clinical pathway considering the clinical value and associated radiation risks of available imaging tests?". Phys Med 2017; 43: 178-85.
  15. Vock P. Clinical perspective on diagnostic X-ray examinations of pregnant patients - What to take into account. Phys Med 2017; 43: 165-71.
  16. Valentin J. Avoidance of radiation injuries from medical interventional procedures. Ann ICRP 2000; 30(2): 7-67.
Journal of Isfahan Medical School
Volume 37, Issue 519 - Serial Number 519
January and February 2019
Pages 237-241

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History

  • Receive Date: 19 February 2019
  • Revise Date: 27 May 2024
  • Accept Date: 06 April 2022

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