@01-258_via99-011_hepatoma_onscreen

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1 Lei Xing, Ph.D. & Jacob Haimson Professor Department of Radiation Oncology & MIPS Stanford University School of Medicine Case study TrueBeam 6 MV FFF RapidArc Tx of a Lung SBRT 3D modeling Treatment planning Pt setup and treatment delivery Imaging 4D imaging Biological imaging 4D modeling 4D planning 3D/4D CBCT Gated tx planning Adaptive therapy (imaging, planning, delivery) Day 0 Day 4 Day 24 Head and neck CT, PET, and IMRT treatment plan Supine Craniospinal Irradiation with RA Jianzhou Chen, Z. Chen, T. Atwood, I. Gibbs, S. Soltys, & L. Xing, Supine Craniospinal Irradiation with VMAT to Improve Target Dose Conformity and Homogeneity, JRO, 202.

2 Available Imaging Tools sensitivity Optical imaging PET SPECT XFCT XLCT MRSI MRI US CT Spatial resolution Principle Radioluminescence & X-ray Luminescence CT CT Molecular Imaging using nanophosphors a Ionizing radiation Optical radiation Current applications - PET and SPECT scintillators - CT detectors - Portal imaging - Dosimetry - Scintillation counting - High-energy physics G. Pratx, 202 Pratx, Sun, Carpenter & Xing, Optics Letters, 20. CT Molecular Imaging using QD and nanophosphors QD70-RGD peptide A h E B C D F a b c d a b Modification of QD70-Dendron with a dimeric RGD peptide, RGD 2. B: Excellent solubility and monodisperity in aqueous solution for the QD70-Dendron (left) and QD70-RGD 2 (right). C: TEM image of QD70-RGD 2. D: UV absorbance and NIRF of the QD70-Dendron (bottom) and QD70-RGD 2 (top). In vivo NIRF imaging of QD70-RGD 2 (active targeting, E) and QD70-Dendron (passive targeting, F) in mice bearing SKOV3 tumor (Cheng s lab). QD705 QD800 2

3 Photon yield vs dose a b d e 0.3 pm Gd 2O 2S:Eu LaO 2:Eu 0. 2 µg/ml Phos Phos in Agar White light c Luminescence Tissue-mimicking material f g cgy Varian 00keV fluoro 0 cgy 00 cgy The white light image (a) and luminescence image (b) of the nanophosphor phantom. (c) X-ray luminescence spectrum of Gd 2 O 2 S:Eu. The Gd 2 O 2 S:Eu phantoms with different concentrations (d) and their X-ray luminescence images under different X-ray irradiation dose cgy (e), 0 cgy (f) and 00 cgy (g). Multiplexing X-ray induced optical luminescence images ssdna-ag x Lysozyme-Au 8 BSA-Au Int BSA- Au 25 Blank Water ssdna- Lyz- Ag x Au (a) Schematic of the locations of each type of RLNP. The inactive particles are indicated with the abbreviation (Ctrl). (b,c) The unmixed signal from the BaYF 4 :Tb and BaYF 4 :Eu particles, respectively. (d) The unmixed multiplexed image with colorbars for the relative concentrations of BaYF 4 :Tb and BaYF 4 :Eu. (C. Carpenter et al, 202) X-ray induced optical luminescence intensities Gultathione-Au 8?? Or polymer-au ion complex Int. Blank. Water solution solid

4 X-ray Luminescence Tomography G. Pratx et al, IEEE Trans. Med. Ima., 200 % Agar 99% water TiO2 for optical sctter Ink for optical absorption 00 µm phosphor cm phosphor plug Reconstruction: ML-EM Molecular sensitivity = 0.3 cgy Noise from counting statistics: Y i ~ Poisson(y i ) 0.3 pm Log-likelihood: Optimization: cgy 0 cgy 2 µg/ml Expectation-Maximization: Tissue-mimicking material 00 cgy Spatially Encoded Light Emission X-ray Luminescence Tomography C. Carpenter et al, PMB 202 4

5 Spatial resolution ~ mm Reconstruction & linearity.5 50 radial positions 0 mg/ml 5 Phantom mm 00 radial positions 64 angles 28 angles Offset (background) Reconstructed image (ML-EM) Sinogram Simulation vs Experiment Sinogram Reconstructed image 0 mg/ml 5 mg/ml Simulation mg/ml Experiment XFCT CT Sinograms (top) and reconstructed CT images (bottom) for XFCT (left) and transmission CT (right) of the low-resolution phantom loaded with gold for a 0. mgy imaging dose. (Magda Bozalova et al) M. Balazova, Y. Kuang, G. Pratx, L. Xing, X-ray Fluorescence Molecular CT Imaging, IEEE Trans Med Ima., 202 M. Balazova, Y. Kuang, G. Pratx, L. Xing, X-ray Fluorescence Molecular CT Imaging, IEEE Trans Med Ima., 202 5

6 M. Balazova, Y. Kuang, G. Pratx, L. Xing, X-ray Fluorescence Molecular CT Imaging, IEEE Trans Med Ima., 202 Au Pt Fig.. (left) Proposed XFCT/CT system. (top) Physical mechanism of X-ray fluorescence from K-shell electrons. K. Yu et al, AAPM 202 (best paper in imaging) Medical Physics Letters, 203. Multiplexing K. Yu et al, AAPM 202 (best paper in imaging) Medical Physics Letters, 203. Multiplexing Overcoming Compton Scatter K. Yu et al, AAPM 202 (best paper in imaging) Medical Physics Letters, 203. Moiz Ahmad et al, Order of Magnitude Sensitivity Increase in X-ray Fluorescence CT (XFCT) Imaging With an Optimized Spectro Ima, 203 6

7 Going Beyond K-Schell Imaging High-sensitivity x-ray fluorescence CT imaging of Cisplatin with L-shell x-rays CT FBP ML-EM (w/o correction) Magda ML-EM Bazalova (w correction) et al, to be published 30 kev 5 kev Magda Bazalova, to be published, kev Figure 2: CT images (first column, W/L = 800/0) and XFCT images reconstructed with filtered backprojection (FBP, second column) and maximum likelihood expectation maximization (ML-EM, 20 High-sensitivity x-ray fluorescence CT imaging of Cisplatin with L-shell x-rays X-ray acoustic tomography (XACT) with pulsed X-ray beam from a medical linear accelerator Liangzhong Xiang, Bin Han, Colin Carpenter, Guillem Pratx, Yu Kuang, and Lei Xing Figure 5: Profiles along a horizontal (left) and vertical (right) line across the phantom for the 5 kev images reconstructed with FBP (green), ML-EM without (blue) and with (red) attenuation correction.the actual profile is marked by the black dashed line. The accuracy of concentration reconstruction is significantly increased when attenuation correction is applied.! 30 picoseconds per pulse Xiang L et al, Medical Physics Letters, 203 Interaction of X-ay with endogenous or exogenous media provides the basis for X-ray molecular imaging. imaging is possible. XFCT, XLCT and XACT are a few examples of X-ray molecular/physiological imaging that are being developed at Stanford. 7