The measurement of proton stopping power using proton-cone-beam computed tomography.

A cone-beam computed tomography (CT) system utilizing a proton beam has been developed and tested. The cone beam is produced by scattering a 160 MeV proton beam with a modifier that results in a signal in the detector system, which decreases monotonically with depth in the medium. The detector system consists of a Gd2O2S:Tb intensifying screen viewed by a cooled CCD camera. The Feldkamp-Davis-Kress cone-beam reconstruction algorithm is applied to the projection data to obtain the CT voxel data representing proton stopping power. The system described is capable of reconstructing data over a 16 x 16 x 16 cm3 volume into 512 x 512 x 512 voxels. A spatial and contrast resolution phantom was scanned to determine the performance of the system. Spatial resolution is significantly degraded by multiple Coulomb scattering effects. Comparison of the reconstructed proton CT values with x-ray CT derived proton stopping powers shows that there may be some advantage to obtaining stopping powers directly with proton CT. The system described suggests a possible practical method of obtaining this measurement in vivo.

[1]  P. Munro,et al.  X-ray quantum limited portal imaging using amorphous silicon flat-panel arrays. , 1998, Medical Physics (Lancaster).

[2]  E. Pedroni,et al.  The calibration of CT Hounsfield units for radiotherapy treatment planning. , 1996, Physics in medicine and biology.

[3]  Sjirk N. Boon,et al.  Fast 2D phantom dosimetry for scanning proton beams. , 1998, Medical physics.

[4]  R. Wilson.  Radiological use of fast protons. , 1946, Radiology.

[5]  L. Burkinshaw,et al.  Tomographic Reconstruction from Experimentally Obtained Cone-Beam Projections , 1987, IEEE Transactions on Medical Imaging.

[6]  L. Feldkamp,et al.  Practical cone-beam algorithm , 1984 .

[7]  Eric C. Frey,et al.  Modeling the scatter response function in inhomogeneous scattering media for SPECT , 1994 .

[8]  Robert J. Schneider,et al.  Range modulators for protons and heavy ions , 1975 .

[9]  Piotr Zygmanski.  Proton -cone -beam -computed -tomography , 1998 .

[10]  J A Rowlands,et al.  X-ray detectors for digital radiography. , 1997, Physics in medicine and biology.

[11]  A M Koehler,et al.  Quantitative proton tomography: preliminary experiments. , 1976, Physics in medicine and biology.

[12]  Larry E. Antonuk,et al.  Large area, flat-panel a-Si:H arrays for x-ray imaging , 1993, Medical Imaging.

[13]  Kenneth M. Hanson,et al.  COMPUTED TOMOGRAPHY USING PROTON ENERGY LOSS , 1981, Physics in Medicine and Biology.

[14]  Jay S. Loeffler,et al.  Radiation Oncology: Technology and Biology , 1994 .

[15]  M. Goitein.  Three-dimensional density reconstruction from a series of two-dimensional projections , 1972 .

[16]  R M Leahy,et al.  Derivation and analysis of a filtered backprojection algorithm for cone beam projection data. , 1991, IEEE transactions on medical imaging.

[17]  E. Frey,et al.  A practical method for incorporating scatter in a projector-backprojector for accurate scatter compensation in SPECT , 1993 .

[18]  J. N. Bradbury,et al.  The Application of Protons to Computed Tomography , 1978, IEEE Transactions on Nuclear Science.

[19]  B. Heijmen,et al.  Portal dose measurement in radiotherapy using an electronic portal imaging device (EPID). , 1995, Physics in medicine and biology.

[20]  S Webb.  A modified convolution reconstruction technique for divergent beams. , 1982, Physics in medicine and biology.

[21]  Rolf Clackdoyle,et al.  Stable and efficient shift-variant algorithm for circle-plus-lines orbits in cone-beam CT , 1996, Proceedings of 3rd IEEE International Conference on Image Processing.

[22]  Joseph F. Janni,et al.  Energy loss, range, path length, time-of-flight, straggling, multiple scattering, and nuclear interaction probability , 1982 .

[23]  M Goitein,et al.  A pencil beam algorithm for proton dose calculations. , 1996, Physics in medicine and biology.

[24]  A. Cormack.  Representation of a Function by Its Line Integrals, with Some Radiological Applications , 1963 .

[25]  E. V. Benton,et al.  Computerized Heavy-Ion Tomography , 1981, Other Conferences.

[26]  S. Shalev,et al.  Monte Carlo optimization of metal/phosphor screens at megavoltage energies. , 1993, Medical physics.

[27]  D. R. Machen,et al.  Proton computed tomography of human specimens , 1982 .

[28]  D F Jackson,et al.  The relation between X-ray CT numbers and charged particle stopping powers and its significance for radiotherapy treatment planning. , 1983, Physics in medicine and biology.

[29]  B. F. Logan,et al.  The Fourier reconstruction of a head section , 1974 .

[30]  B. A. Ludewigt,et al.  Instrumentation for Treatment of Cancer Using Proton and Light-Ion Beams , 1993 .

[31]  Kenneth M. Hanson,et al.  Proton Computed Tomography , 1979, IEEE Transactions on Nuclear Science.

[32]  L. L. Kanstein,et al.  Axial Scanning with 900 MeV Alpha Particles , 1975, IEEE Transactions on Nuclear Science.

[33]  H Liu,et al.  Charge-coupled device detector: performance considerations and potential for small-field mammographic imaging applications. , 1992, Medical physics.

[34]  H. Tuy.  AN INVERSION FORMULA FOR CONE-BEAM RECONSTRUCTION* , 1983 .

[35]  L. Verhey,et al.  Proton beam therapy. , 1982, Annual review of biophysics and bioengineering.