SU-C-303-04: Evaluation of On- and Off-Line Bioluminescence Tomography System for Focal Irradiation Guidance

Authors

  • Zhang B,

    1. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD
    2. Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD
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  • Wang K,

    1. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD
    2. Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD
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  • Iordachita I,

    1. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD
    2. Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD
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  • Reyes J,

    1. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD
    2. Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD
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  • Tran P,

    1. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD
    2. Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD
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  • Wong J

    1. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD
    2. Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, MD
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Abstract

Purpose:

We have developed offline and on-board bioluminescence tomography(BLT) systems for the small animal radiation research platform(SARRP) for radiation guidance of soft tissue targets. We investigated the effectiveness of offline BLT guidance.

Methods:

CBCT is equipped on both the offline BLT system and SARRP that are 10 ft. apart. To evaluate the setup error during animal transport between the two systems, we implanted a luminescence source in the abdomen of anesthetized mice. Five mice were studied. After CBCT was acquired on both systems, source centers and correlation coefficients were calculated. CBCT was also used to generate object mesh for BLT reconstruction. To assess target localization, we compared the localization of the luminescence source based on (1)on-board SARRP BLT and CBCT, (2)offline BLT and CBCT, and (3)offline BLT and SARRP CBCT. The 3rd comparison examines if an offline BLT system can be used to guide radiation when there is minimal target contrast in CBCT.

Results:

Our CBCT results show the offset of the light source center can be maintained within 0.2 mm during animal transport. The center of mass(CoM) of the light source reconstructed by the offline BLT has an offset of 1.0 ± 0.4 mm from the ‘true’ CoM as derived from the SARRP CBCT. The results compare well with the offset of 1.0 ± 0.2 mm using on-line BLT.

Conclusion:

With CBCT information provided by the SARRP and effective animal immobilization during transport, these findings support the use of offline BLT in close vicinity for accurate soft tissue target localization for irradiation. However, the disadvantage of the off-line system is reduced efficiency as care is required to maintain stable animal transport. We envisage a dual use system where the on-board arrangement allows convenient access to CBCT and avoids disturbance of animal setup. The off-line capability would support standalone longitudinal imaging studies.

The work is supported by NIH R01CA158100 and Xstrahl Ltd. Drs. John Wong and Iulian Iordachita receive royalty payment from a licensing agreement between Xstrahl Ltd and Johns Hopkins University. John Wong also has a consultant agreement with Xstrahl Ltd.

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