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  • [Phys Med.] Dose perturbation and inhomogeneity of multi-arrays of 125I seed-loaded stent for treatment of portal vein tumor thrombosis.

    서울대 / 정성문, 예성준*

  • 출처
    Phys Med.
  • 등재일
    2019 Oct
  • 저널이슈번호
    66:1-7. doi: 10.1016/j.ejmp.2019.09.077. Epub 2019 Sep 26.
  • 내용

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    Abstract
    PURPOSE:
    To investigate the dosimetry of 125I seed-loaded stent system currently used for an adjuvant treatment of portal vein tumor thrombosis (PVTT).

    METHODS:
    The stent system consisted of an inner metallic stent and outer seed-loaded capsules. Four arrays of 125I seeds were attached longitudinally to the outer surface of the stent at 90° separation. 145 Gy was prescribed at 5 mm from the axes of seed-arrays. For the geometries of the 4-array, and potential 6- and 8-array configurations, treatment planning system (TPS) and Monte Carlo (MC) calculations were performed to evaluate 3D dose distributions and dosimetric impact of the metallic stent.

    RESULTS:
    The MC simulations indicated the metallic stent reduced a dose to the prescription points by over 10%, compared to the water-based TPS results. The total activity calculated by the water-based TPS to deliver the prescription dose should compensate for this amount of reduction. The MC- and TPS-calculated doses normalized to the prescription points for the current configuration were in agreements within 4.3% on a cylindrical surface along 5 mm from the axes of seed-arrays. The longitudinal underdosage worsened as approaching the edge of arrays, and ranged from 2.8% to 25.5%. The angular underdosage between neighboring arrays was 2.1%-8.9%.

    CONCLUSIONS:
    With this compensation and a special care of near-edge underdosage, the current 4-array system can provide adequate dose coverage for treatment of PVTT. Further dosimetric homogeneity can be achieved using 6-or 8-array configurations.

     


    Author information

    Jung S1, Shen S2, Ye SJ3.
    1
    Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea.
    2
    Department of Radiation Oncology, University of Alabama at Birmingham Medical Center, Birmingham, AL, USA.
    3
    Biomedical Radiation Sciences, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea; Robotics Research Laboratory for Extreme Environment, Advanced Institutes of Convergence Technology, Seoul National University, Suwon, Gyeonggi-do, South Korea. Electronic address: sye@snu.ac.kr.

  • 키워드
    (125)I seed-loaded stent; Dose perturbation; Monte Carlo; Portal vein tumor thrombosis
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