(12) United States Patent
`Graf
`
`(10) Patent N0.:
`(45) Date of Patent:
`
`US 6,888,919 B2
`May 3, 2005
`
`US006888919B2
`
`DE
`DE
`EP
`EP
`EP
`FR
`FR
`GB
`
`$0
`
`(54) RADIOTHERAPY APPARATUS EQUIPPED
`WITH AN ARTICULABLE GANTRY FOR
`POSITIONING AN IMAGING UNIT
`,
`-
`-
`~
`-~
`Inventor. Ulrich Martin Graf, Leigruppenstrasse
`(CH)
`.
`.
`.
`(73) Assignee: Varian Medical Systems, Inc., Palo
`A110; CA(US)
`
`(75)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`.
`.
`.
`a s.
`U S C 154(b) by 188 d y
`
`(21) APP1 N01 10/033,327
`.
`.
`F1160"
`
`(22)
`(65)
`
`NOV‘ 2’ 2001
`Prior Publication Data
`US 2004/0024300 A1 Feb. 5, 2004
`
`Int. Cl.7 .................................................. A6iN 5/10
`(51)
`(52) U.S. Cl.
`........................................ .. 378/65; 378/197
`(58) Field of Search ......................... .. 378/19, 98.8, 65,
`378/195, 196, 197, 198, 9; 250/374
`
`(56)
`
`References Cited
`U~S~ PATENT DOCUMENTS
`3,133,227 A
`5/1964 Brown et al.
`3,144,552 A
`8/1964 Schonberg
`3,193,717 A
`7/1965 Nunan
`4,149,247 A
`4/1979 Pavkovich et al.
`4,149,248 A
`4/1979 PaVk0Vich et al.
`4,208,675 A
`6/1980 B31011 61 31
`
`4>209>700 A
`4,521,808 A
`4,593,967 A
`4,675,731 A
`4,679,076 A
`4,726,046 A
`4,741,621 A
`4,825,393 A
`4,853,777 A
`4,868,844 A
`5,080,100 A
`
`0/1980 Nunan
`6/1985 Orig et al.
`6/1986 Haugen
`6/1987 Takasu et al.
`7/1987 Vikterlof et al.
`2/1933 Nunan
`5/1988 Taft et a1,
`4/1989 Nishiya
`8/1989 Hupp
`9/1989 Nunan
`1/1992 Trotel
`
`*
`
`5,099,505 A
`5,117,445 A
`1168532 A
`5,335,255 A
`2
`,
`,
`5,471,516 A
`5,537,452 A *
`5,692,507 A
`5,751,781 A *
`5,956,382 A
`
`.......... .. 378/65
`
`........... .. 378/65
`
`3/1992 Seppi et 211.
`5/1992 SCPP1 61 111
`12/1992 SePP1e1a1~
`8/1994 Seppi et al.
`2/1995 Swerdloff et al.
`8
`/1995 Yu et 211.
`11/1995 Nunan
`7/1996 Shepherd et al.
`12/1997 Seppi et al.
`............... .. 378/65
`5/1998 Brown et al.
`9/1999 Wiener—AVnear et al.
`C
`,
`d
`( Ommue )
`FOREIGN PATENT DOCUMENTS
`42 23 488 A1
`1/1994
`196 14 643 A1
`10/1997
`0062941 B1
`9/1984
`0205720 A1
`12/1986
`0480035 B1
`11/1994
`2 269 745
`11/1975
`2 551 664
`3/1985
`1 328 033
`8/1973
`
`A1
`
`OTHER PUBLICATIONS
`Ragan, “Correction for Distrotion in a Beam Outline Trans-
`fer Device in Radiotherapy CT—Based Simulation”, Med.
`Phys. 20 (1), Jan./Feb. 1993, pp. 179-185.
`i‘;§‘?’co’*J?fi§;?J‘$3,133?1E,E’1iE§E‘§£dV1§i;‘;‘i,i‘;§§’,?“]§?§I
`medicine, 1994, Citation from Dissertation Abstracts, 1
`page,
`
`d
`C t.
`( 0“ mus )
`Primary Examiner—EdWard J. Glick
`Assistant Examiner—Allen C. Ho
`
`(74) Attorney Agent or Firm—Blakely Sokoloff Taylor &
`Zafman LLP ’
`’
`’
`’
`
`(57)
`
`ABSTRACT
`.
`.
`.
`.
`An apparatus including a first radiation source attached to a
`first gantry, at least one second radiation source, a second
`gantry that
`is rotatable; and an imager attached to an
`articulable end of the second gantry.
`
`26 Claims, 10 Drawing Sheets
`
`
`
`Page 1 of 18
`
`Elekta Exhibit 1001
`
`Page 1 of 18
`
`Elekta Exhibit 1001
`
`

`
`US 6,888,919 B2
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`.................. .. 378/20
`
`2/2000 Ivan et al.
`6,031,888 A *
`3/2000 Roos et 211.
`6,041,097 A
`8/2000 Murad
`6,104,778 A
`............ .. 378/92
`8/2000 Hanover et al.
`6,104,780 A *
`11/2000 Schweikard et 211.
`6,144,875 A
`4/2001 Meulenbrugge et 211.
`6,222,901 B1
`6,307,914 B1 * 10/2001 Kunieda et al.
`............ .. 378/65
`6,325,537 B1 * 12/2001 Watanabe ................. .. 378/197
`6,381,302 B1
`4/2002 Berestov
`6,385,286 B1
`5/2002 Fitchard et 211.
`.. 313/105 CM
`6,429,578 B1 *
`8/2002 Danielsson et al.
`6,508,586 B2 *
`1/2003 Oota ........................ .. 378/196
`2001/0008271 A1
`7/2001 Ikeda et al.
`2003/0007601 A1
`1/2003 Jaffray et 211.
`OTHER PUBLICATIONS
`
`Keys, A CCTV-Microcomputer Biostereometric System for
`Use in Radiation Therapy (Topography, Medical Physics,
`Tissue Compensators), 1984, Citation from Energy Science
`and Technology, 1 page.
`Kutcher et al., “Three dimensional radiation treatment plan-
`ning”, Citation from Engineering Index, 1988, 2 pages.
`Redpath, et al., “Use of a Simulator and Treatment Planning
`Computer as a CT Scanner for Radiotherapy Planning”,
`1984, Citation from INSPEC., 1 page.
`Elliott, “Interactive Image Segmentation for Radiation
`Treatment Planning”, IBM Systems Journal, 1992, Citation
`from Medline (R) Database, 1 page.
`Kushima et al., “New Development of Integrated CT Simu-
`lation System for Radiation Therapy Planning”, Kobs J Med
`Sci., 1993, Citation from Medline (R) Database, 1 page.
`Gademann et al., “Three—Dimensional Radiation Planning.
`Studies on Clinical Integration”, Strahlenther Onkol, 1993,
`1 page.
`Ragan, “Correction for Distortion in a Beam Outline Trans-
`fer Device in Radkotherapy CT—based Simulation”, Med
`Phys., 1993, 1 page.
`Andrew et al., “A Video—Based Patient Contour Acquisition
`System for the Design of Radiotherapy Compensators”,
`Med Phys., 1989, 1 page.
`Reynolds, “An Algorithm for Three—Dimensional Visual-
`ization of Radiation Therapy Beams”, Med Phys., 1988, 1
`page.
`Mohan, “Intersection of Shaped Radiation Beams with
`Arbitrary Image Sections”, Comput Methods Programs
`Biomed, 1987, 1 page.
`Brewsterfuauf, “Automatic Generation of Beam Apertures”,
`Medical Physics, 1993, 1 page.
`Hara et al., “Radiotherapeutic System”, 00480035/EP-B1,
`Citation from World Patent, 1994 1 page.
`Moore, “Radiation Image Generating System and Method”,
`1992020202/WO—A1, 1 page.
`Seppi, “Computed Tomography Apparatus Using Image
`Intensifier Detector”, 1992000567/WO-A1, 1 page.
`Bova, “Dosimetric Technique for Stereotactic Radiosur-
`gery”, 1990014129/WO—A1, 1 page.
`Kazufumi, “Radiation Treatment Device”, 05057028 JP, 1
`page.
`Inamura, “CT Simulator For Radiotherapy”, 63294839 JP, 1
`page.
`Moore, “Radiation Image Generating System and Method”,
`Citation from US Patent, 2 pages.
`Nishihara, “Therapeutic Apparatus”, 2 pages.
`
`Page 2 of 18
`
`Jaffray, “Cone-Beam CT: Application in Image Guided
`External Beam Radiotherapy and Brachytherapy”, IEEE,
`2000, 2 pages.
`Ning et al., “An Image Intensifier—Based Volume Tomo-
`graphic Angiography Imaging System: System Evaluation,”
`SPIE, vol. 2432, pp. 280-290.
`“Advanced Workstation for Irregular Field Simulation and
`Image Matching”, Copyright 1999, MDS Nordion, 7 pages.
`Balter, James M. et al., “Daily Targeting of Intrahepatic
`Tumors for Radiotherapy,” Int. J. Radiation Oncology Biol.
`Phys., vol. 52, No. 1 (2002), pp. 266-271.
`Swindell, William et al., “Computed Tomography With a
`Linear Accelerator With Radiotherapy Applications,” Med.
`Phys., vol. 10, No. 4, Jul./Aug. 1983; pp. 416-420.
`Mosleh-Shirazi, Mohammad Amin et al., “A Cone-Beam
`Megavoltage CT Scanner for Treatment Verification in Con-
`formal Radiotherapy,” Radiotherapy and Oncology, vol. 48
`(1998), pp. 319-328.
`Midgley, S. et al., “A Feasibility Study for Megavoltage
`Cone Beam CT Using A Commercial EPID,” Phys. Med.
`Biol., vol. 43 (1998), pp. 155-169.
`Ruchala, K.J. et al., “Megavoltage CT on a Tomotherapy
`System,” Phys. Med. Biol., vol. 44 (1999), pp. 2597-2621.
`Nakagawa, Keiichi, M.D. et al., “Megavoltage CT-Assisted
`Stereotactic Radiosurgery for Thoracic Tumors: Original
`Research in the Treatment of Thoracic Neoplasms,” Int. J .
`Radiation Oncology Biol. Phys., vol. 48, No. 2, (2000), pp.
`449-457.
`
`Groh, B.A. et al., “A Performance Comparison of Flat-Panel
`Imager-Based MV and kV Conebeam CT,” Med. Phys., vol.
`29, No. 6, Jun. 2002, pp. 967-975.
`Uematsu, Mir1oru et al., “Daily Positioning Accuracy of
`Frameless Stereotactic Radiation Therapy With a Fusion of
`Computed Tomography and Linear Accelerator (FOCAL)
`Unit: Evaluation of Z-Axis With a Z-Marker,” Radio-
`therapy and Oncology, vol. 50, No. 3, Mar. 1999, pp.
`337-339.
`
`Uematsu, Minoru, M.D. et al., “A Dual Computed Tomog-
`raphy Linear Accelerator Unit for Stereotactic Radiation
`Therapy: A New Approach Without Cranially Fixated Ste-
`reotactic Frames,” Int. J. Radiation Oncology Biol. Phys.,
`vol. 35, No. 3 (1996), pp. 587-592.
`Uematsu, Minoru, M.D. et al, “Intrafractional Tumor Posi-
`tion Stability During Computed Tomography (CT)-Guided
`Frameless Stereotactic Radiation Therapy for Lung or Liver
`Cancers With a Fusion of CT and Linear Accelerator
`
`(FOCAL) Unit,” Int. J . Radiation Oncology Biol. Phys., vol.
`48, No. 2 (2000), pp. 443-448.
`Jaffray, David A., Ph.D. et al., “A Radiographic and Tomo-
`graphic Imaging System Integrated Into a Medical Linear
`Accelerator for Localization of Bone and Soft-Tissue Tar-
`
`gets,” Int. J . Radiation Oncology Biol. Phys., vol. 45, No. 3
`(1999), pp. 773-789.
`Pisani, Laura, M.S. et al., “Setup Error in Radiotherapy:
`On-line Correction Using Electronic Kilovoltage and Mega-
`voltage Radiographs,” Int. J. Radiation Oncology Biol.
`Phys., vol. 47, No. 3 (2000), pp. 825-839.
`Drake, D.G. et al, “Characterization of a Fluoroscopic
`Imaging System for kV and MV Radiography,” Med. Phys.,
`vol. 27, No. 5, May 2000, pp. 898-905.
`
`Page 2 of 18
`
`

`
`US 6,888,919 B2
`Page 3
`
`Jaffray, D.A. and Siewerdsen, J .H., “Cone-Beam Computed
`Tomography with a Flat—Panel Imager: Initial Performance
`Characterization,” Med. Phys., Vol. 27, No. 6, Jun. 2000,
`1311-1323.
`
`Fahrig, R. and Holdsworth, D. W., “Three-Dimensional
`Computed Tomographic Reconstruction Using a C—Arm
`Mounted XRII: Image Based Correction of Gantry Motion
`Nonidealities,” Med. Phys., Vol. 27, No. 1, Jan. 2000, pp.
`30-38.
`
`Feldkamp, L.A. et al. “Practical Cone—Beam Algorithm,” J.
`Opt. Soc. Am. A., Vol. 1, No. 6, Jun. 1984; pp. 612-619.
`Siewerdsen, Jeffrey H. and Jaffray, David A., “Optimization
`of X—Ray Imaging Geometry (With Specific Application to
`Flat—Panel Cone—Beam Computed Tomography),” Med.
`Phys., Vol. 27, No. 8, Aug. 2000, pp. 1903-1914.
`
`Siewerdsen, Jeffery H. and Jaffray, David A., “Cone-Beam
`Computed Tomography With a Flat—Panel Imager: Magni-
`tude and Effects of X—Ray Scatter,” Med. Phys., Vol. 28, No.
`2, Feb. 2001, pp. 220-231.
`
`Cho, Paul S. et al., “Cone-Beam CT for Radiotherapy
`Applications,” Phys. Med. Biol., Vol. 40 (1995), pp.
`1863-1883.
`
`Masahiro et al., “Patient Beam Positioning System Using
`CT Images”, Phys. Med. Biol., 1982, Vol. 27, No. 2, pp.
`301-305, printed in Great Britain.
`
`* cited by examiner
`
`Page 3 of 18
`
`Page 3 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 1 of 10
`
`US 6,888,919 B2
`
`€<.o__n_VEo:
`
`
`
`._ommE_o_Smam._m£N \
`
`nil’
`
`Page 4 of 18
`
`Page 4 of 18
`
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 2 of 10
`
`US 6,888,919 B2
`
`ammo:_.2...
`
`mosom2Em.
`
`:38
`
`
`
`ofiocmguucooow
`
`
`
`858:o_.m_c£
`
`
`
`
`
`8.58cozmfim.o=:maEm£
`
`Page 5 of 18
`
`Page 5 of 18
`
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 3 of 10
`
`US 6,888,919 B2
`
`g\
`
`FIG.2A
`
`226
`
`220
`
`216~/‘
`
`Page 6 of 18
`
`Page 6 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 4 of 10
`
`US 6,888,919 B2
`
`FIG.2B
`
`Page 7 of 18
`
`Page 7 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 5 of 10
`
`US 6,888,919 B2
`
`Page 8 of 18
`
`Page 8 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 6 of 10
`
`US 6,888,919 B2
`
`FIG.3B
`
`Page 9 of 18
`
`Page 9 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 7 of 10
`
`US 6,888,919 B2
`
`FIG.3C
`
`Page 10 of 18
`
`Page 10 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 8 of 10
`
`US 6,888,919 B2
`
`Page 11 of 18
`
`Page 11 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 9 of 10
`
`Page 12 of 18
`
`

`
`U.S. Patent
`
`May 3,2005
`
`Sheet 10 of 10
`
`US 6,888,919 B2
`
`Page 13 of 18
`
`Page 13 of 18
`
`

`
`US 6,888,919 B2
`
`1
`RADIOTHERAPY APPARATUS EQUIPPED
`WITH AN ARTICULABLE GANTRY FOR
`POSITIONING AN IMAGING UNIT
`
`FIELD OF THE INVENTION
`
`The present invention pertains in general to oncology
`radiation therapy. In particular, the invention involves an
`X-ray and electron radiotherapy machine used in radiation
`treatment applications.
`BACKGROUND OF THE INVENTION
`
`The use of linear accelerators for the generation of either
`electron radiation or X-ray radiation is well known. After
`generating a stream of electrons, components in the radio-
`therapy machine can convert
`the electrons to X-rays, a
`flattening filter can broaden the X-ray beam, the beam can
`be shaped with a multileaf collimator, and a dose chamber
`can be arranged at the exit of an accelerator. A detector is
`mounted and is mechanically or electronically scanned
`synchronously with the mechanically or electronically
`scanned paraxial X-ray beam, providing continuous moni-
`toring of alignment of the patient’s anatomy. These systems
`typically provide either static fixed field radiation therapy or
`fully dynamic intensity modulated radiation therapy (IMRT)
`used by the medical community in the treatment of cancer.
`One of the challenges inherent in radiotherapy treatment
`is the accurate positioning of the tumor in the radiation field.
`The main sources of the problem result from the fact that
`there is a natural motion of organs inside the body, which
`can range, for example, from approximately a millimeter in
`the case of the brain inside the skull, to several centimeters
`for the organs in the trunk above the diaphragm. Another
`factor relates to changes which occur in the tumor over time
`because of successful treatment. Over the course of treat-
`ment and as the tumor shrinks in volume, normal tissue
`which had been displaced returns to its original position
`within the treatment volume.
`
`To accurately verify tumor positioning, detectors such as
`X-ray films or electronic X-ray imaging systems are com-
`monly used in the radiation treatment diagnostic process. In
`the case of electronic imaging,
`the megavolt therapeutic
`X-rays emerging from the patient can be used to generate
`images. However, these methods at target location deliver
`images of low contrast and insufficient quality. As a result,
`imaging with megavoltage radiation is used primarily for
`verification, that is to confirm that the target volume has
`been radiated. These problems associated with utilizing high
`energy X-rays produced by a megavolt electron beam are the
`result of interacting with matter mostly due to Compton
`scattering, in which the probability of interactions is pro-
`portional to the electron density. Low energy X-rays typi-
`cally have energies of about 125 peak kilovolts (kVp) or
`below, where a significant portion of the interactions with
`matter is photoelectric and the interactions are proportional
`to the cube of electron density. Low energy X-rays are more
`useful to provide accurate targeting or diagnostic informa-
`tion because tissue in the human body is typically of low
`density and as a result, the contrast achieved in low energy
`X-rays is far superior to that obtained with megavoltage
`X-rays. Therefore, distinctions of landmark features and the
`imaging of other features not perceptible with high energy
`X-rays are possible using kV energy. As a result,
`two
`separate imagers, each sensitive to an energy range,
`i.e.
`either the megavolt source or the kV source are used in
`treatment.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`One method taught is to incorporate a low energy X-ray
`source inside the treatment head of the accelerator capable
`of positioning itself to be coincident with the high energy
`X-ray source. With this approach, a high energy X-ray target
`is modified to include a compact 125 kV electron gun to be
`mounted to a moveable flange at the base of the high energy
`source with the cathode of the gun operably coupled to the
`upstream end of a drift tube. By engaging an actuator, the
`electron gun can be provide target information for diagnostic
`imaging. An imager can be used that is sensitive to kV range
`radiation energies and positioned opposite the kV electron
`gun with the target volume in between. Therapeutic treat-
`ment can then be started or resumed by positioning the
`high-energy or megavolt electron beam trajectory to be in
`line with the target volume. A second imager is positioned
`opposing the megavolt source that is more sensitive to the
`radiation energy used in the therapeutic and verification
`procedure.
`FIGS. 1A & 1B are illustrations of a radiotherapy clinical
`treatment machines to provide therapeutic and diagnostic
`radiation, each directed to a different imager. FIG. 1A is an
`illustration of the radiotherapy machine having a single
`diagnostic X-ray source directed to a single imager. The
`radiotherapy machine has a therapeutic radiation source
`directed to a therapeutic imager along a first axis and the
`diagnostic X-rays are directed to the second imager along an
`axis that is 90° from the first axis. This apparatus places the
`therapeutic radiation source capable of propagating radia-
`tion in the megavoltage (MV) energy range and the kilo-
`voltage (kV) diagnostic radiation source on different support
`structures. Each radiation source has an imager opposing
`that is in line to the respective radiation source along an axis.
`FIG. 1B is an illustration of the radiotherapy machine
`having dual diagnostic X-ray sources, each directed to a
`separate diagnostic imager. The radiotherapy machine has a
`therapeutic radiation source capable of propagating a thera-
`peutic radiation beam along an axis to a therapeutic imager.
`Attached to support structures are two diagnostic radiation
`sources that can propagate diagnostic X-rays at off-angles
`from the therapeutic radiation axis. Each radiation source as
`an imager in line to receive the radiation. The entire structure
`of radiation sources and imagers can be pivoted together by
`a common base.
`
`Cancer patients usually need to lie on their backs for
`radiation treatment and the patient’s anatomy can shift
`markedly from supine to prone positions. In order to irra-
`diate the target volume from different directions without
`turning the patient over, 360° rotation of the support struc-
`ture holding the radiation source is needed. For convenience
`in setting up the patient, the isocenter around which the
`equipment rotates should not be too high above the floor.
`Adequate space must be provided between the isocenter and
`the radiation head for radiation technologist access to the
`patient and for rotation clearance around the patient. This
`leaves a quite limited amount of space for the various
`components such as the radiation shielding in the radiation
`head, and particularly for the magnet system. To a significant
`extent, the design challenge over the years has been to stay
`within this space, to reduce cost where possible, and while
`making major advances in the clinical utility of machines.
`
`SUMMARY OF THE INVENTION
`
`A radiotherapy clinical treatment machine can have a
`therapeutic radiation source on a first pivotable gantry. A
`second pivotable gantry can have a single imager mounted
`on an articulable end of the second gantry and a diagnostic
`
`Page 14 of 18
`
`Page 14 of 18
`
`

`
`US 6,888,919 B2
`
`3
`radiation energy source can be mounted on a retractable
`opposing end of the second gantry. The first gantry and the
`second gantry may pivot on a common centerline. The
`imager can be a multiple-energy imaging unit which can be
`naturally in line with the diagnostic radiation source or the
`second gantry can pivot to place the multiple-energy imag-
`ing unit in line with the therapeutic radiation source. Piv-
`oting the second gantry may require the diagnostic radiation
`source first be retracted to provide clearance where it rotates
`past the therapeutic radiation energy source.
`This arrangement
`for positioning the multiple-energy
`imaging unit to be in line with either one of the radiation
`sources can provide improved imaging useful in directing
`the treatment beams used in radiation therapy. A first energy
`level in the kV range can radiate a target volume to provide
`diagnostic quality image information from the multiple-
`energy imaging unit. The diagnostic information can be used
`to better direct radiation at a second energy level in the MV
`range for therapeutic radiation of the target volume and from
`which verification information from the multiple-energy
`imaging unit can then be acquired. The second gantry can
`pivot, extend/retract, and/or articulate to receive diagnostic
`radiation or therapeutic radiation. The application of thera-
`peutic radiation and diagnostic radiation can alternate in any
`combination to provide diagnostic imaging and verification
`imaging as a result of the degrees of freedom available to
`position the single multiple-energy imaging unit.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The present invention is illustrated by way of example
`and not
`limitation in the figures of the accompanying
`drawings, in which like references indicate similar elements
`and in which:
`
`FIG. 1A is an illustration of the radiotherapy machine
`having a single diagnostic X-ray source directed to a single
`imager.
`FIG. 1B is an illustration of the radiotherapy machine
`having dual diagnostic X-ray sources, each directed to a
`separate diagnostic imager.
`FIG. 2A is an illustration of a radiotherapy clinical
`treatment machine in one embodiment using a multiple-
`energy imaging unit.
`FIG. 2B is an illustration of an alternate embodiment of
`
`treatment machine using the
`the radiotherapy clinical
`multiple-energy imaging unit.
`FIG. 3A is an illustration in one embodiment of the
`
`starting position for
`machine.
`
`the radiotherapy clinical
`
`treatment
`
`FIG. 3B is an illustration in one embodiment of a diag-
`nostic radiation source in use.
`FIG. 3C is an illustration in one embodiment of the
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`diagnostic radiation source providing multiple-slices of a
`target volume.
`FIG. 3D is an illustration in one embodiment of a thera-
`
`55
`
`peutic radiation source providing radiation to the target
`volume.
`FIG. 3E is an illustration in one embodiment of the
`
`therapeutic radiation source rotated to a new position to
`provide radiation to the target volume.
`FIG. 3F is an illustration in one embodiment of another
`
`rotation of the first gantry and dose of therapeutic radiation
`applied to the target volume from another position.
`DETAILED DESCRIPTION
`
`60
`
`65
`
`A method and apparatus for a radiotherapy clinical treat-
`ment machine for positioning an imager to oppose one or
`
`4
`more radiation sources is disclosed. For purposes of dis-
`cussing the invention, it is to be understood that various
`terms are used by those knowledgeable in the art to describe
`apparatus, techniques, and approaches.
`In the following description, for purposes of explanation,
`numerous specific details are set forth in order to provide a
`thorough understanding of the present invention. It will be
`evident, however, to one skilled in the art that the present
`invention may be practiced without these specific details. In
`some instances, well-known structures and devices are
`shown in gross form rather than in detail in order to avoid
`obscuring the present invention. These embodiments are
`described in sufficient detail to enable those skilled in the art
`
`to practice the invention, and it is to be understood that other
`embodiments may be utilized and that logical, mechanical,
`electrical, and other changes may be made without departing
`from the scope of the present invention.
`In one embodiment, a method and apparatus is disclosed
`for an X-ray and electron radiotherapy clinical treatment
`machine. The apparatus and method can position and
`re-position a single imager to receive radiation from more
`than one radiation source. Imagers can generally provide
`high quality imaging from one radiation energy range and
`less quality imaging from other radiation energy ranges and
`such an imager can be incorporated into this invention.
`However, in this embodiment, the imager can be capable of
`receiving and displaying high quality imaging information
`from multiple energies (multiple-energy imaging unit). One
`of the energies can be a source of therapeutic energy and
`another a source of diagnostic X-rays, both of which can
`alternately activate the multiple-energy imaging unit for
`high quality verification imaging and high quality diagnostic
`imaging respectively. The radiotherapy machine can gener-
`ate an electron beam, generally in the 4 to 25 megavolt (MV)
`range, to provide electrons or X-rays to a volume within a
`patient undergoing treatment,
`i.e. a target volume. The
`multiple-energy imaging unit can display radiographic infor-
`mation from the megavolt radiation sufficient to provide
`verification that the target volume is being radiated.
`This single multiple-energy imager can also be optimized
`to work with energy in the kilovolt (kV) range. The multiple-
`energy imaging unit can receive X-rays in the kV range to
`provide more accurate diagnostic information on the size,
`shape, and location of the target volume. Repeated X-ray
`shots with kV energy that alternate with therapeutic radia-
`tion can reduce target error such as by directing a continuous
`adjustment of the beam shaping by a dynamic multileaf
`collimator and by providing targeting information to the
`therapeutic radiation source.
`The diagnostic radiation source can be rotated about the
`target volume for CT single or multiple CT images using a
`fan x-ray beam, or by using a cone x-ray beam where
`volumetric information can be constructed. Also, if a partial
`data set is acquired from a limited number of images taken
`at specific angles around the target volume, enough infor-
`mation can be obtained with the help of previously acquired
`volumetric information to provide the 3D reconstruction of
`the anatomy of interest. As a result,
`imaging from the
`diagnostic X-rays can provide targeting information to accu-
`rately direct the therapeutic X-rays to the target volume from
`any angle while effectively excluding healthy tissue from
`injury. Furthermore, the diagnostic source can be operated
`either in a continuous or pulsed manner to provide a real
`time or quasi-real time fluoroscopic image of moving inter-
`nal anatomy. This fluoroscopic image can be used to provide
`information to track the motion of anatomy being treated.
`Normal respiration or unwanted voluntary or involuntary
`
`Page 15 of 18
`
`Page 15 of 18
`
`

`
`US 6,888,919 B2
`
`5
`patient movement may cause such motion. This motion
`tracking information can in turn be used to adjust treatment
`parameters or gate the treatment beam off and on such that
`the anatomy intended to be treated is always in the intended
`position within the treatment beam.
`FIG. 2A is an illustration of one embodiment of an imager
`positioning gantry on a radiotherapy clinical
`treatment
`machine where the imager can be a multiple-energy imaging
`unit. As shown in FIG. 2A, the radiotherapy clinical treat-
`ment machine 200 can have an imager positioning gantry to
`position the multiple-energy single imager to oppose one or
`more radiation sources. A therapeutic radiation source 202
`and a diagnostic radiation source 204 can be positioned on
`separate arms (gantries), 206 and 208, where one arm
`(second gantry) 208 is nestled within the other (first gantry)
`206, and with both arms 206 and 208 on a common pivot
`axis 210. The two arms 206 and 208 can pivot 210 inde-
`pendently and in addition, the inner arm (second gantry) 208
`can extend and retract the diagnostic radiation source 204
`for positioning and clearance. The therapeutic radiation
`source 202 can be positioned on the first arm (first gantry)
`206 which can be pivotally attached to a vertical stand or
`base 216 to allow an effective 360° rotation of the thera-
`
`peutic radiation source 202 about the target volume 224.
`The imager can be a multiple-energy imaging unit and can
`be attached to the inner arm (second gantry) 208 at the end
`opposite from the diagnostic radiation source 204. The inner
`arm end 220 attached to the multiple-energy imaging unit
`212 can articulate the multiple-energy imaging unit 212 into
`alignment with either radiation source 202 or 204. Attached
`to the second gantry 208, the multiple-energy imaging unit
`212 is in natural alignment to receive radiation from an
`extended diagnostic radiation source 204. Fine adjustments
`to place the multiple-energy imaging unit into alignment
`with and at the proper distance from the radiation source 202
`or 204 are also accomplished with the articulating portion of
`the second gantry 208. Alternately, the diagnostic radiation
`source 204 can be retracted for clearance so that the inner
`
`arm 220 can rotate and the multiple-energy imaging unit 212
`articulate until the multiple-energy imaging unit 212 is in
`alignment
`to receive radiation from the other radiation
`source 202 or 204.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`The first gantry 206 and the second gantry 208 can have
`a “C” shape (C-Arm) and the second gantry 208 can have a
`smaller radius of curvature and be nestled within the first
`
`45
`
`gantry 206. The diagnostic X-ray source 204 can be
`mounted on one end 218 of the second gantry 208 and the
`multiple-energy imaging unit 212 to oppose on the other end
`220. The radiation source end 218 of the second gantry 208
`can extend or retract the diagnostic X-ray source 204 to
`provide clearance around the therapeutic radiation geometry
`(head) 222 on the first gantry 206. The diagnostic X-ray
`source 204 can also be extended and retracted, along with
`second gantry 208 rotation, to place the diagnostic X-ray
`source 204 in positions about the target volume 224. The
`articulating end 220 can be attached to an opposite end 220
`of the second gantry C-arm 208 to hold and position the
`multiple-energy imaging unit 212. In one embodiment, the
`articulating end 220 can pivot at three points 226, 227, and
`228 the multiple-energy imaging unit 212 along two inde-
`pendent axes 230 in a plane. The articulating end 220 can
`contain any number of pivot points from single plane pivots
`to ball joints having 360 degrees of rotation for positioning
`the multiple-energy imaging unit. The translatable 230 por-
`tion of the articulating joint can be a set of sliding mecha-
`nisms that include gears and motors which are well known
`to one skilled in the art. The result of such articulation can
`
`50
`
`55
`
`60
`
`65
`
`6
`be to place the multiple-energy imaging unit in alignment
`with, and at a distance from, either of the radiation sources
`202 and 204 with the target volume 224 positioned in
`between. Further,
`the articulating end 220 can retract to
`position the multiple-energy imaging unit 212 ‘into a stowed
`position.
`FIG. 2B is an illustration of an alternate embodiment of
`
`treatment machine using the
`the radiotherapy clinical
`multiple-energy imaging unit. As shown in FIG. 23, the
`therapeutic radiation source 202 and the diagnostic radiation
`source 204 can be positioned adjacent to each other and
`attached at the same end of the first gantry 206. The first
`gantry 206 can rotate about pivot axis 210 to position either
`the therapeutic radiation source 202 or the diagnostic radia-
`tion source 204 into alignment about the target volume 224.
`The second gantry, an inner arm, can be attached to the pivot
`axis 210 with an opposite end 220 attached to the articulat-
`ing multiple-energy imaging unit 212. The multiple-energy
`imaging unit 212 can be rotated and articulated until align-
`ment with either radiation source 202 or 204 is achieved,
`maintaining the target volume 224 in between.
`FIGS. 3A—3E illustrate the operation of one embodiment
`of the radiographic clinical
`treatment machine. FIGS.
`3B—3E retain the target volume 324 but have the patient
`outline 303 removed for clarity. FIG. 3A is an illustration of
`a starting position for the radiotherapy clinical treatment
`machine. A couch 301 can place a patient 303 in a starting
`position. The patient 303 can contain a volume within the
`body that constitutes the targeted volume 324. The first
`gantry 306 can be in an upright position, and the second
`gantry 308 can be upright with the diagnostic radiation
`source 304 in a retracted position. The multiple-energy
`imaging unit 312 can be unstowed and positioned beneath
`the couch 301.
`
`FIG. 3B is an illustration of the diagnostic radiation
`source in use. The second gantry 308 can first rotate to
`provide clearance for the diagnostic radiation source 304
`from the therapeutic radiation source 302. Once the diag-
`nostic radiation source 304 is clear, the second gantry 308
`can further rotate and extend the diagnostic radiation source
`304 to be in alignment with the target volume 324 and
`maintain clearance between interfering geometries, i.e. 302
`and 304. The multiple-energy imaging unit 312 can be
`further articulated and the couch 301 translated and raised or
`
`lowered until a proper alignment and distance is set relative
`to the target volume 324. When in position, the diagnostic
`radiation source 304 can direct an X-ray beam to the target
`volume 324 and then to the multiple-energy imaging unit
`312.
`
`FIG. 3C is an illustration of the diagnostic radiation
`source providing another X-ray view of the target volume
`(not shown) at a new position. The diagnostic radiation
`source 304 and the multiple-energy imaging unit 312 can be
`rotated together by rotating any combination of either the
`first gantry 306 or the second gantry 308 to provide multiple
`X-ray views at different angles that can be assembled to
`generate 3-dimensional images of the target volume.
`FIG. 3D is an illustration of the therapeutic radiation
`source providing radiation to the target volume. After target
`volume definition has be