Monte Carlo simulations for assessment of organ radiation doses and cancer risk in patients undergoing abdominal stent-graft implantation

Eur J Vasc Endovasc Surg. 2014 Jul;48(1):23-8. doi: 10.1016/j.ejvs.2014.03.014. Epub 2014 May 15.

Abstract

Objectives and design: The aim of this work was to assess absorbed radiation doses in selected organs and to estimate cancer and mortality risks in patients undergoing abdominal stent-graft implantation, as a function of age, gender, and anatomical parameters of patients' aneurysms and arteries.

Materials and methods: 297 patients (266 males and 31 females) underwent endovascular aortic aneurysm repair (EVAR) with abdominal stent-graft implantation. Kerma-area products Gy-cm(2) for all implanted patients were collected retrospectively. Entrance surface air kerma (ESAK), doses absorbed by selected organs, and cancer/mortality risks were estimated using Monte Carlo simulation methods (CALDose_X software).

Results: The highest radiation doses were deposited in the skin, gallbladder wall, and colon wall. The highest average cancer risk was found for the youngest group of patients (<60 years old; 1:275) and the lowest for the oldest (>70 years old, 1:735). The radiation-induced risk of cancer mortality (mortality risk) was about 40% lower than radiation-induced cancer occurrence risk. Aneurysm neck angulations >45° had a significant impact on ESAK, as well as increasing cancer and mortality risks.

Conclusions: The main factors increasing cancer risk are young age and aneurysm neck angulations >45°, which determines the difficulty of proper stent-graft placement. However, the radiation risk associated with the stent-graft implantation procedure is relatively low, and EVAR should not be avoided.

Keywords: Aneurysm; Endovascular aortic aneurysm repair (EVAR); Organ dose assessment; Radiation risk; Stent-graft implantation.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aortic Aneurysm, Abdominal / diagnostic imaging*
  • Aortic Aneurysm, Abdominal / mortality
  • Aortic Aneurysm, Abdominal / surgery*
  • Aortography / adverse effects*
  • Blood Vessel Prosthesis Implantation* / adverse effects
  • Blood Vessel Prosthesis Implantation* / mortality
  • Computer Simulation*
  • Endovascular Procedures* / adverse effects
  • Endovascular Procedures* / mortality
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Monte Carlo Method
  • Neoplasms, Radiation-Induced / epidemiology*
  • Neoplasms, Radiation-Induced / mortality
  • Poland / epidemiology
  • Radiation Dosage*
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Treatment Outcome