GB2127173A - Thin fieldlight mirror for medical electron accelerators - Google Patents
Thin fieldlight mirror for medical electron accelerators Download PDFInfo
- Publication number
- GB2127173A GB2127173A GB08322100A GB8322100A GB2127173A GB 2127173 A GB2127173 A GB 2127173A GB 08322100 A GB08322100 A GB 08322100A GB 8322100 A GB8322100 A GB 8322100A GB 2127173 A GB2127173 A GB 2127173A
- Authority
- GB
- United Kingdom
- Prior art keywords
- mirror
- visible light
- electron
- ray
- thin
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/10—Beam splitting or combining systems
- G02B27/1073—Beam splitting or combining systems characterized by manufacturing or alignment methods
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
- A61B6/08—Auxiliary means for directing the radiation beam to a particular spot, e.g. using light beams
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N5/00—Radiation therapy
- A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
- A61N5/1048—Monitoring, verifying, controlling systems and methods
- A61N5/1049—Monitoring, verifying, controlling systems and methods for verifying the position of the patient with respect to the radiation beam
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/10—Beam splitting or combining systems
- G02B27/14—Beam splitting or combining systems operating by reflection only
- G02B27/142—Coating structures, e.g. thin films multilayers
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/08—Mirrors
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
- G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
- G21K1/02—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators
- G21K1/04—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating using diaphragms, collimators using variable diaphragms, shutters, choppers
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
- G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
- G21K1/10—Scattering devices; Absorbing devices; Ionising radiation filters
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
- H01J37/02—Details
- H01J37/22—Optical or photographic arrangements associated with the tube
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
- A61N5/00—Radiation therapy
- A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
- A61N5/1048—Monitoring, verifying, controlling systems and methods
- A61N5/1049—Monitoring, verifying, controlling systems and methods for verifying the position of the patient with respect to the radiation beam
- A61N2005/1056—Monitoring, verifying, controlling systems and methods for verifying the position of the patient with respect to the radiation beam by projecting a visible image of the treatment field
Abstract
The mirror for reflecting visible light to simulate the radiation field of a medical electron beam applicator is made of a thin film of a plastic material with superior resistance to radiation damage so that the applicator requires no power- driven moving parts to retract the mirror and the mirror can be left fixed in the beam.
Description
SPECIFICATION
Thin field light mirror for medical electron accelerators
Background of the Invention
The present invention relates to the art of visually simulating the radiation pattern formed by a medical electron beam applicator and more particularly to a mirror which may be left fixed in an x-ray or electron beam as a part of an optical system for such a purpose.
In operating an x-ray apparatus, it is desirable to be able to visualize its radiation boundaries by a visible light pattern and this is accomplished generally by means of an optical system including a source of visible light located at some distance away from the x-ray beam and a reflector so positioned in the path of the beam that the light source is virtually imaged at the origin of the x-ray beam. This reflector may be a conventional glass mirror affixed in the beam path and such an optical system is disclosed in U. S.
Pat. No. 3,767,931.
This same optical system, however, cannot be used in the case of an electron beam because the energy loss and electron scattering in the mirror would be intolerable. Although plastic mirrors have been used in high-energy electron beams in the Gev range for reflecting visible light, the absorption rate of electron energy generally increases at lower beam energies. In the case of an apparatus for medical treatment, the energy of electron beam is generally lower than 50 Mev and it is not desirable that a mirror designed for a high-energy electron beam machine should be left fixed in the path of a lower energy electron beam such as that from a medical electron accelerator.The conventional mirror must be made retractable, or the entire optical system, including the mirror, must alternatively be so mounted that it can be moved out of the way whether the machine is operated in the x-ray or electron treatment mode. Such methods, however, generally require powerdriven moving parts; they require very tight repositioning tolerances; and the mechanisms are costly to manufacture.
Summary of the Invention
It is, therefore, an object of the present invention to provide a mirror which may be left fixed in an x-ray or electron beam without compromising the beam qualities significantly.
It is another object of the present invention to provide an electron accelerator for medical treatment which includes a means affixed in the beam path for reflecting visible light to simulate the radiation field pattern.
Brief Description of the Drawings
Fig. 1 is a sectional partly schematic view of a medical beam applicator with an irretractably positioned mirror embodying the present invention when the applicator is being used in the electron mode.
Fig. 2 is a sectional partly schematic view of the applicator of Fig. 1 when it used in the x-ray mode.
Detailed Description of the Invention
Referring now to Figs. 1 and 2, there is shown schematically a medical electron accelerator providing both electron and x-ray modes. Shown therein in particular is an optical system embodying the present invention by means of which the field to be irradiated can be simulated visually. A charged particle accelerator (not shown) generates an electron beam 11 which, when the machine is operating in the x-ray mode as in Fig. 2, bombards a target 12 to produce an x-ray beam in a generally conical shape around the original direction of the beam axis.When the machine is used in the electron mode as shown in Fig. 1, the target 12 is withdrawn from the path of the beam 11 and the electron beam 11 from the accelerator spreads into a generally conical form due to the electrostatic repulsion among the electrons and the transverse components of their initial velocities.
The beam is directed through a conicallyshaped aperture in primary collimator 15. The aperture is a tapered central passageway which, together with the adjustable jaws 16 and 17, serves to collimate the beam. In Figs.
1 1 and 2, the upper jaws 16 and lower jaws 17 are positioned in 90 rotation about the original direction of the beam 11.
A flattening means for promoting a uniform beam intensity throughout the beam crosssection is disposed in the beam path. For the x-ray mode, use may be made of an equalizing filter 20 of the type disclosed in the U.S.
Pat. No. 4,286,167.
For the electron mode, the equalizing filter 20 is retracted and a foil or foils 21 are inserted transversely across the path of the beam at an appropriate position or positions depending on the electron beam energy and other characteristics thereof.
A A mirror 25 is mounted on a fixed frame 26 and is oriented appropriately so that visible light from a source 27 located externally of the a confining structure 28 will pass through an appropriately located passageway 29 to the mirror for reflection therefrom onto the object 30 to be irradiated in such a way that a virtual image of light source 27 will be formed at the apex of the cone into the shape of which the beam 11 is transformed by means of the primary collimator 15 and the jaws 16 and 17. In the case of x-ray mode, the apex may be considered to be at target 12. For the electron mode, the same position may be treated as the apex and the collimator 1 5 and the jaws 16 and 17 may be adjusted accordingly although the target 12 is withdrawn.
Mirror 25 would ideally be completely transparent to both x-ray and electron beams.
Since conventional glass mirrors are not sufficiently transparent to lower-energy electrons, mirror 25 is a thin film of a plastic material metallized with an aluminum coating. It is made by securing a sheet of plastic under tension over a suitably flat circular ring. The plastic thickness is about 2 mils (about 5mg/cm2 in surface density). The thickness of the aluminum coating is of the order of the wave length of visible light to be reflected and hence is negligible as compared to that of the plastic film. A number of plastics or other materials can be used for the production of such a film, but the present material of choice is Dupont's KaptonTM plastic because of its superior resistance to radiation damage.
The present invention has been described above in terms of only one embodiment. The above description, however, is to be considered as illustrative rather than as limiting, and this invention is accordingly to be broadly construed. For example, the radiation pattern to be simulated need not be that of an electron beam or an x-ray beam. It is envisioned that the accelerator and target 12 in the drawing could be replaced by a radioactive material so that the apparatus of this invention could be used with a gamma-ray beam. It is similarly envisioned that the visible light source 27 could be replaced by an ultraviolet source. A large variety of flattening means can be employed for uniformizing the radiation intensity throughout the cross section of the beam. The means may also include an ion chamber disposed adjacent the filter 20, for measuring total radiation intensity. The mirror may be made of many different types of plastics, depending on their transmission of beams and resistance against radiation damage. Its thickness and shape can be varied, depending on the situation although a thickness in the range of 1 to 5 mils is generally envisioned. Jaws and other means for collimating the beam may be arranged in different manners.
Claims (6)
1. A medical apparatus adapted to irradiate a treatment field with a beam of electrons, said apparatus comprising a means for visualizing said treatment field by a visible light field, said visualizing means including a source of visible light positioned outside the path of said beam and a mirror irretractably fixed in the path of said beam and oriented so that the visible light from said source reflected by said mirror irradiates said treatment field.
2. The apparatus of claim 1 wherein said mirror is a film of a plastic material metallized with an aluminum coating.
3. The apparatus of claim 2 wherein the thickness of said film is in the range of 1 to 3 mils.
4. The apparatus of claim 2 wherein the surface density of said film is 5 mg/cm2.
5. The apparatus of claim 2 wherein said plastic material has high resistance to radiation damage.
6. The apparatus of claim 1 which is also adapted to irradiate said treatment field with a beam of x-rays.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US41679582A | 1982-09-13 | 1982-09-13 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8322100D0 GB8322100D0 (en) | 1983-09-21 |
| GB2127173A true GB2127173A (en) | 1984-04-04 |
Family
ID=23651334
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08322100A Withdrawn GB2127173A (en) | 1982-09-13 | 1983-08-17 | Thin fieldlight mirror for medical electron accelerators |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS5964068A (en) |
| FR (1) | FR2551664A1 (en) |
| GB (1) | GB2127173A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4065221A4 (en) * | 2019-11-27 | 2023-12-27 | Intraop Medical Corporation | Electron beam radiation system with advanced applicator coupling system having integrated distance detection and target illumination |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS629458U (en) * | 1985-07-01 | 1987-01-21 | ||
| US6104778A (en) * | 1997-10-16 | 2000-08-15 | Varian Systems, Inc. | X-ray treatment method and apparatus |
| US6888919B2 (en) | 2001-11-02 | 2005-05-03 | Varian Medical Systems, Inc. | Radiotherapy apparatus equipped with an articulable gantry for positioning an imaging unit |
| US7227925B1 (en) | 2002-10-02 | 2007-06-05 | Varian Medical Systems Technologies, Inc. | Gantry mounted stereoscopic imaging system |
| US7657304B2 (en) | 2002-10-05 | 2010-02-02 | Varian Medical Systems, Inc. | Imaging device for radiation treatment applications |
| US7945021B2 (en) | 2002-12-18 | 2011-05-17 | Varian Medical Systems, Inc. | Multi-mode cone beam CT radiotherapy simulator and treatment machine with a flat panel imager |
| US7412029B2 (en) | 2003-06-25 | 2008-08-12 | Varian Medical Systems Technologies, Inc. | Treatment planning, simulation, and verification system |
| US20070003010A1 (en) | 2005-04-29 | 2007-01-04 | Varian Medical Systems Technologies, Inc. | Radiation systems with imaging capability |
| US7880154B2 (en) | 2005-07-25 | 2011-02-01 | Karl Otto | Methods and apparatus for the planning and delivery of radiation treatments |
| WO2008063573A2 (en) | 2006-11-17 | 2008-05-29 | Varian Medical Systems Technologies, Inc. | Dynamic patient positioning system |
| USRE46953E1 (en) | 2007-04-20 | 2018-07-17 | University Of Maryland, Baltimore | Single-arc dose painting for precision radiation therapy |
| WO2011160235A1 (en) | 2010-06-22 | 2011-12-29 | Karl Otto | System and method for estimating and manipulating estimated radiation dose |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB372592A (en) * | 1931-06-16 | 1932-05-12 | John Gunning | Improvements in apparatus for automatically operating gas valves |
| GB647541A (en) * | 1946-11-16 | 1950-12-13 | Andre Clement Coutant | Improvements relating to cameras |
| GB1066839A (en) * | 1964-11-24 | 1967-04-26 | Peterlite Products Ltd | Mirrors |
| GB1313296A (en) * | 1969-05-22 | 1973-04-11 | Philips Electronic Associated | X-ray apparatus |
| GB1388342A (en) * | 1972-08-21 | 1975-03-26 | Medinova Ab | Screening or aperture device for an x-ray apparatus |
| GB1437283A (en) * | 1973-04-26 | 1976-05-26 | Machlett Lab Inc | Radiographic apparatus |
| EP0004694A2 (en) * | 1978-04-12 | 1979-10-17 | Philips Norden AB | Medical irradiating apparatus |
| GB2054188A (en) * | 1979-07-11 | 1981-02-11 | Bratland E A | Method for Making Mirrors and Mirrors Made Thereby |
| GB2074344A (en) * | 1980-04-23 | 1981-10-28 | Marui Ind | Method using transparent synthetic resin plate |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL219231A (en) * | 1957-07-22 | |||
| JPS5367099A (en) * | 1976-11-26 | 1978-06-15 | Toshiba Corp | Electron beam shape accelerator |
-
1983
- 1983-08-17 GB GB08322100A patent/GB2127173A/en not_active Withdrawn
- 1983-08-29 JP JP15656783A patent/JPS5964068A/en active Pending
- 1983-09-13 FR FR8314556A patent/FR2551664A1/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB372592A (en) * | 1931-06-16 | 1932-05-12 | John Gunning | Improvements in apparatus for automatically operating gas valves |
| GB647541A (en) * | 1946-11-16 | 1950-12-13 | Andre Clement Coutant | Improvements relating to cameras |
| GB1066839A (en) * | 1964-11-24 | 1967-04-26 | Peterlite Products Ltd | Mirrors |
| GB1313296A (en) * | 1969-05-22 | 1973-04-11 | Philips Electronic Associated | X-ray apparatus |
| GB1388342A (en) * | 1972-08-21 | 1975-03-26 | Medinova Ab | Screening or aperture device for an x-ray apparatus |
| GB1437283A (en) * | 1973-04-26 | 1976-05-26 | Machlett Lab Inc | Radiographic apparatus |
| EP0004694A2 (en) * | 1978-04-12 | 1979-10-17 | Philips Norden AB | Medical irradiating apparatus |
| GB2054188A (en) * | 1979-07-11 | 1981-02-11 | Bratland E A | Method for Making Mirrors and Mirrors Made Thereby |
| GB2074344A (en) * | 1980-04-23 | 1981-10-28 | Marui Ind | Method using transparent synthetic resin plate |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4065221A4 (en) * | 2019-11-27 | 2023-12-27 | Intraop Medical Corporation | Electron beam radiation system with advanced applicator coupling system having integrated distance detection and target illumination |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2551664A1 (en) | 1985-03-15 |
| GB8322100D0 (en) | 1983-09-21 |
| JPS5964068A (en) | 1984-04-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3360647A (en) | Electron accelerator with specific deflecting magnet structure and x-ray target | |
| EP0314231B1 (en) | Multileaf collimator and related apparatus | |
| GB2127173A (en) | Thin fieldlight mirror for medical electron accelerators | |
| EP0824026B1 (en) | Radiation treatment apparatus and method | |
| US5287396A (en) | X-ray examination apparatus | |
| KR100256849B1 (en) | Multiple-channel, total-reflection optic with controllable divergence | |
| Zhu et al. | The head‐scatter factor for small field sizes | |
| KR920007772B1 (en) | Moderator and beam port assembly for neutron radiography | |
| JPH0631885B2 (en) | Collimator | |
| US4347440A (en) | Filter arrangement for an x-ray apparatus | |
| US2882413A (en) | Luminescent screen | |
| CA2939811C (en) | X-ray collimator | |
| JPH0467875A (en) | Radiation irradiating field limiting device | |
| US4582999A (en) | Thermal neutron collimator | |
| CA2742313A1 (en) | X-ray beam processor | |
| JPH0390900A (en) | Neutron radiographic apparatus | |
| US6678352B1 (en) | Anti-scattering x-ray raster | |
| LaRiviere | Thin fieldlight mirror for medical electron accelerators | |
| West et al. | Proton-scattering radiography | |
| JPH021999A (en) | X-ray laser beam generating method and device thereof | |
| CN107847200B (en) | Imaging apparatus and system with enhanced X-ray radiation | |
| JP7297341B1 (en) | Neutron capture therapy device | |
| US20100158196A1 (en) | Radiation beam blocker with non-cylindrical through-hole causing reduced geometric unsharpness in radiographic image, and method for the preparation thereof | |
| US20210257123A1 (en) | X-ray collimator assembly and x-ray source assembly | |
| Sabbas et al. | Collimated electron beams and their associated penumbra widths |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |