OtherBasic Science Investigations

A 3-Dimensional Absorbed Dose Calculation Method Based on Quantitative SPECT for Radionuclide Therapy: Evaluation for 131I Using Monte Carlo Simulation

Michael Ljungberg, Katarina Sjögreen, Xiaowei Liu, Eric Frey, Yuni Dewaraja and Sven-Erik Strand
Journal of Nuclear Medicine August 2002, 43 (8) 1101-1109;

Article Figures & Data

Figures

  • FIGURE 1.
    FIGURE 1.

    (A) Planar projection of defined activity distribution. (B) Monte Carlo simulated projection image of 131I of same activity distribution in air, that is, including only deterioration caused by collimator response and septal penetration. (C) Projection image obtained when including attenuation and scatter, which thus simulates real patient situation. (D) Projection image obtained for 32- to 132-keV scatter energy window, used for image registration procedure.

  • FIGURE 2.
    FIGURE 2.

    Mass density images used to mimic CT-derived mass density map for quantification. Maps 1–3 show transversal, coronal, and sagittal slices for the 3 test cases, before and after registration to SPECT image.

  • FIGURE 3.
    FIGURE 3.

    Flow chart describing methodology of quantification procedure and evaluation. Known activity map and gold standard absorbed dose distribution are compared with corresponding maps obtained from quantitative SPECT calculation scheme.

  • FIGURE 4.
    FIGURE 4.

    Transversal section of absorbed dose distribution for slice through lungs (top row) and liver (bottom row) for different cases. Images were all normalized to same gray level.

Tables

  • TABLE 1

    The Defined Activity and Activity Concentration for Major Organs

    OrgankBq/cm3Volume (cm3)MBq in VOI
    Bladder67553.7
    Blood pool267528141.1
    Bone marrow8344537.1
    Heart8336830.7
    Kidney334299100.0
    Liver1671,151192.1
    Lung172,41340.3
    Pelvis10033333.4
    Spleen20021943.8
    Urine16712020.0
    Bone structures501,18759.4
    Remaining tissues1719,917332.6
  • TABLE 2

    Activity Concentration per Voxel Within VOI

    Simulated organKnownAirNonuniform attenuation correction
    ESSE + map 0ESSE + map 1ESSE + map 2ESSE + map 3
    Kidney334 ± 0.0248 ± 75.3255 ± 73.1253 ± 72.4258 ± 75.0258 ± 75.7
    Lung17 ± 0.028 ± 16.423 ± 16.224 ± 16.827 ± 19.425 ± 17.2
    Pancreas17 ± 0.047 ± 18.667 ± 22.168 ± 22.266 ± 22.165 ± 21.7
    Spleen200 ± 0.0163 ± 54.9173 ± 51.9174 ± 51.2166 ± 47.3169 ± 46.7
    Liver167 ± 0.0152 ± 36.6164 ± 40.5163 ± 39.8166 ± 40.4166 ± 41.3
    Heart83 ± 0.0117 ± 52.3128 ± 55.5129 ± 54.8127 ± 55.3127 ± 55.7
    Bone marrow83 ± 0.067 ± 21.081 ± 25.480 ± 23.379 ± 26.781 ± 22.3
    Total activity in phantom (GBq)1.0001.0891.0901.0901.0881.096

    • Data are mean ± SD, in kBq/cm3.

  • TABLE 3

    Absorbed Dose per Voxel Within VOI

    Simulated organKnownAirNonuniform attenuation correction
    ESSE + map 0ESSE + map 1ESSE + map 2ESSE + map 3
    Kidney10.1 ± 0.58.7 ± 2.48.6 ± 2.28.5 ± 2.28.7 ± 2.38.7 ± 2.3
    Lung2.4 ± 0.43.3 ± 1.52.5 ± 1.22.3 ± 1.02.3 ± 1.02.4 ± 1.1
    Pancreas1.3 ± 0.22.2 ± 0.72.8 ± 0.82.9 ± 0.82.8 ± 0.82.8 ± 0.8
    Spleen6.2 ± 0.45.8 ± 1.75.9 ± 1.65.9 ± 1.55.7 ± 1.45.7 ± 1.4
    Liver5.5 ± 0.45.6 ± 1.25.8 ± 1.35.7 ± 1.35.8 ± 1.35.8 ± 1.3
    Heart3.1 ± 0.34.4 ± 1.74.6 ± 1.74.7 ± 1.64.7 ± 1.74.6 ± 1.7
    Bone marrow2.9 ± 0.32.6 ± 0.72.9 ± 0.92.8 ± 0.82.8 ± 0.92.9 ± 0.8

    • Data are mean ± SD, in grays.

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