Program Information
An Integrated Multimodality Imaging and Precision Radiation Research Platform
J Shi, T Udayakumar, N Dogan, A Pollack, Y Yang*, University of Miami Miller School of Medicine, Miami, FL
Presentations
MO-DE-605-1 (Monday, July 31, 2017) 1:45 PM - 3:45 PM Room: 605
Purpose: To develop an integrated multimodality imaging and precision radiation platform that can be used for image guided radiotherapy and molecular assessment of treatment response. Image modalities include CT, bioluminescence tomography (BLT) and fluorescence molecular tomography (FMT).
Methods: CT faces challenges in differentiating poorly vascularized tumors from surrounding tissues. In contrast, BLT and FMT can directly monitor cancer activities using tumor-targeting molecular probes. CT, BLT and FMT have been integrated onboard previously developed image guided Small Animal Arc Radiation Treatment (iSMAART) platform to provide complimentary image information. The CT system is composed of a double-focus x-ray tube, a rotating animal stage and a flat panel detector. The BLT and FMT systems are composed of a CCD camera coupled with high-speed lens and optical filter, and aligned orthogonally to the CT system. A multi-wavelength laser was used to excite fluorophores for the FMT. All the image modalities were geometrically registered with each other. The CT provides animal anatomy to construct 3D meshes for BLT/FMT reconstruction. In vivo experiments were conducted on different orthotopic tumor models, i.e. prostate and breast tumors, to evaluate imaging performance, particularly in localizing the tumor and recovering its volume. Iodinated contrast CT was used to benchmark against BLT/FMT. In addition, tumor response following a single-fraction radiation of 5 Gy was assessed with CT and BLT.
Results: The precision for CT-guided irradiation is <0.4mm. The difference in the tumor location between BLT/FMT and CT is <0.5mm. There were strong correlations in the tumor volume between BLT and CT (R² = 0.87) and between FMT and CT (R²=0.94). CT/BLT quantitatively assessed the tumor response following radiation.
Conclusion: Based on high-quality multimodality imaging, the iSMAART can accurately map the animal anatomy, precisely guide tumor irradiation, reliably evaluate treatment response, and thus is an invaluable platform for preclinical radiobiology research.
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