System for the delivery of proton therapy

• US 7,560,715 B2
• Filed: 02/19/2005
• Issued: 07/14/2009
• Est. Priority Date: 04/27/2004
• Status: Expired due to Fees

• Current Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Original Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Inventors: Pedroni, Eros
• Primary Examiner(s): Wells; Nikita
• Assistant Examiner(s): Smith; Johnnie L
• Application Number:
  US11/587,832
• Publication Number:
  US 20080023644A1
• Time in Patent Office: 1,606 Days
• Field of Search: 250/491.1, 250/492.3, 250/396.ML, 250/505.1, 250/298, 250/400
• US Class Current: 250/492.3
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 2005/1095 Elements inserted into the radiation path within the system, e.g. filters or wedges
• CPC Class Codes: A61N 5/10 X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy A61N5/01 takes precedence
• CPC Class Codes: A61N 5/1043 Scanning the radiation beam, e.g. spot scanning or raster scanning
• CPC Class Codes: G21K 1/093 by magnetic means
• CPC Class Codes: G21K 5/04 with beam-forming means
• CPC Class Codes: H05H 7/00 Details of devices of the types covered by groups H05H9/00, H05H11/00, H05H13/00

Abstract

A process for an intensity-modulated proton therapy of a predetermined volume within an object includes discretising the predetermined volume into a number of iso-energy layers each corresponding to a determined energy of the proton beam. A final target dose distribution is determined for each iso-energy layer. The final target dose distribution or at least a predetermined part of this final target dose distribution is applied by parallel beam scanning by controlling the respective beam sweepers, thereby scanning one iso-energy layer after the other using an intensity-modulated proton beam while scanning a predetermined iso-energy layer.

Claims

1. A system for an intensity-modulated proton therapy of a predetermined volume within an object, the system comprising:

a) a proton source for generating a proton beam being adjustable with respect to beam intensity;

b) a degrader being optionally disposed in the proton beam for attenuating energy of protons in the proton beam to a desired proton energy in the proton beam;

c) a beam transport system being supported by a support frame pivotable around an optical axis;

said beam transport system including;

d) a plurality of proton beam bending and/or focusing units;

e) a beam nozzle having an outlet for the proton beam for penetrating a predetermined volume of the object;

f) a beam bending magnet being disposed upstream of said nozzle; and

g) a couple of sweeper magnets being disposed upstream of said beam bending magnet for sweeping the proton beam in both lateral directions before the proton beam enters into said beam bending magnet,

h) said beam nozzle defining a cross-sectional scanning area substantially perpendicular to the proton beam in the range of 10 cm×

30 cm, and

i) said sweeper magnets and said beam bending magnet being controlled to substantially provide a parallel beam orientation over a complete cross-sectional scanning area and for delivering a substantially 1;

1 beam image of the proton beam before entering into said beam bending magnet as compared to the beam image after the bending.

2. The system according to claim 1, wherein a preabsorber body is optionally disposed between the outlet of the nozzle and the object.

3. The system according to claim 1, wherein the cross-sectional scanning area is oriented substantially perpendicular to a longitudinal axis of the proton beam, and a moving mechanism for the preabsorber body is provided which is remotely controllable to move the preabsorber body from a parking position into an absorbing position to cover the complete scanning area.

4. The system according to claim 2, wherein the preabsorber body comprises at least one of carbon and beryllium.

5. The system according to claim 1, wherein a collimator is optionally pivoted into the proton beam upstream of the beam bending magnet;

said collimator being movable radially and/or azimuthally.

6. The system according to claim 1, wherein the object is supported by a table which is optionally movable in a plane being substantially perpendicular to the proton beam by a table driving unit, whereby the movement of the table is detected by the table driving unit to control a deflection of the proton beam in a respective sweeper magnet for annihilating a relative shift between the object and the proton beam during dose painting.

7. A process for an intensity-modulated proton therapy of a predetermined volume within an object;

comprising the steps of;

a) discretising the predetermined volume into a number of iso-energy layers each corresponding to a determined energy of the proton beam;

b) determining a final target dose distribution for each iso-energy layer; and

c) applying at least a predetermined part of the final target dose distribution by parallel beam scanning by controlling respective beam sweepers thereby for scanning one iso-energy layer after the other using an intensity-modulated proton beam while scanning a predetermined iso-energy layer.

8. The process according to claim 7, including the step of multiple painting of the respective iso-energy layers, so that each painting delivers a predetermined part of the final target dose distribution.

9. The process according to claim 7, including the step of geometrically field patching by moving a support table continuously, thereby simultaneously compensating the displacement of the motion of the support table with an offset applied to the beam sweepers.

10. The process according to claim 7, including the step of magnetically scanning at each iso-energy layer along the contour of a target volume and on similar equidistant contours in an interior of the target volume, thereby shaping the dose by using beam intensity modulation along the contours.

11. The process according to claim 7, including the step of applying imaged collimation on the scanned beam by using a collimator block being radially and/or azimuthally moved into the proton beam at a coupling point of a beam transport system.

12. The process according to claim 7, including the step of controlling the beam sweepers and beam bending magnet to substantially provide a parallel beam orientation over a complete cross-sectional scanning area and to deliver a substantially 1:

1 beam image of a proton beam before entering into the beam bending magnet as compared to the beam image after the bending.