US 3588499 A
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United States Patent inventor James W. Pegrum Carp, Ontario, Canada Appl. No. 733,904 Filed J one 3, I968 Patented June 28, I97 1 Assignee Atomic Energy of Canada Limited Ottawa, Ontario, Canada Priority June 15, 1967 Canada 993,082
' RADIATION THERAPY MACHINE WITH A ROTATABLE HYPESBARIC CHAMBER HAVING A RADIATION SOURCE MOUNTED THEREIN 4 Claims, 2 Drawing Figs.
US. Cl 250/55, 250/6L5, 250/91 Int. Cl H0 1] 5/48 Field of Search 250/50,
[ 56] References Cited UNITED STATES PATENTS 2,78 I ,454 2/1957 Green et al. 250/91 3,082,322 3/1963 Koemer et a1. 250/91 OTHER REFERENCES Radiation Chamber for Therapeutic Research" Luchiesh et 211., General Electric Review, Vol. 44 No. 8, August, 1941. pp. 426- 428, class 250/50 Primary Examiner Archie R. Borchelt Assistant ExaminerC. E. Church Attorney- Stevens, Davis, Miller and Mosher ABSTRACT: Radiation therapy apparatus includes a patient support within an angularly-movable tank and a housing containing a radiation source carried by the tank such that radiation from the source is directed towards the patient support. The tank housing and source are angularly adjustable relative to the patient support, and the interior of the tank can be pressurized to a pressure above normal atmospheric pressure.
PATENTEU JUH28 I971 FIG.I
jll/enl'ar U ames pegr'um H torneys RADIATION THERAPY MACHINE WITH A ROTATABLE HYPESBARIC CHAMBER HAVING A RADIATION SOURCE MOUNTED THEREIN This invention relates to radiation therapy apparatus in which radiation therapy treatment of a patient (human or animal) is carried out with the patient located in a chamber which is pressurized to a pressure greater than normal atmospheric pressure, such treatment being known as hyperbaric therapy.
Previously, there have been two approaches to hyperbaric therapy. With the first, the patient is located in a small pressurized tank usually fitted with transparent windows of perspex or glass but sometimes made completely of transparent material. The therapy machine is located outside the tank and the treatment has to be carried out through the windows or walls of the tank. The disadvantages of this method are that there is absorption and scatter of the radiation beam by the windows or walls, and thus the tank becomes an obstacle in many treatments. With the second approach, the patient, the therapy machine and possibly the technicians or doctor are all located in a large pressurized chamber. The disadvantages here are high cost, fire hazards due to the presence of electrical devices and services in the chamber, and the undesirability of subjecting medical personnel to pressurization.
An object of this invention is therefore to provide hyperbaric radiation therapy apparatus in which the radiation does not have to pass through windows or walls isolating a pressurized chamber containing a patient from surroundings at normal atmospheric pressure and in which electrical devices and services are not located in the pressurize chamber.
According to the invention, the radiation source is an integral part of a hyperbaric tank and the tank complete with source is rotatable about the patient who is located on a table or stretcher within the tank, the table or stretcher being held stationary by a member which enters the tank through a rotary seal.
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, of which:
FIG. 1 is a diagrammatic side view, partly in section, of hyperbaric radiation therapy apparatus according to one embodiment; and
F IG. 2 is a similar view of the second embodiment.
Referring first to FIG. 1, the therapy apparatus includes a base 1 and a post 2 extending upwardly from the base 1 at a position near one end of the base 1. A cylindrical tank 3 is supported by two sets of rollers 4 each carried by a roller mounting 5 located on the base 1. The tank 3 is mounted with its longitudinal axis horizontal. One end of the tank 3 is adjacent the upper end of the post 2. An arm 6 extending in a horizontal direction from the upper end portion of the post 2 passes through a central aperture in the adjacent end wall 3a of the tank 3, the space between the arm 6 and the wall of the central aperture being sealed by a rotary seal 7. Within the tank 3, the arm 6 carries a stretcher 8 for a patient 9.
A radiation source 11, for example a cobalt 60 source, is secured to a wall of the tank 3, the source 11 actually being contained in a housing 12 forming part of the wall. A counterweight or shield 13 is secured to the wall of the tank 3 at a position opposite the source housing 3 housing 12. The end wall 3b of the tank 3 remote from the post 2 has a door 14 through which the patient 9 can enter and leave the tank 3.
The apparatus also includes means (not shown) for angularly moving the tank 3 and thus the source 11 about the longitudinal axis of the tank 3 relative to the stretcher 8 and patient 9, means for controlling the source 11, and means for pressurizing the tank 3 to a pressure above nonnal atmospher ic pressure, for example up to about 5 atmospheres. The tank 3 is pressurized by supplying air or oxygen under pressure to enrich the oxygen content of the air in the tank 3. The supply of air and oxygen to and the exhaust thereof from the tank 3, control mechanism for adjusting the stretcher position and other services such as cables for recording instruments all enter the tank 3 through the stationary arm 6. Control mechanisms for the source position and a collimator associated with the source are led out via seals through the walls of the tank 3 and move angularly with the tank 3. The controls for the stretcher and collimator may be manual or power operated.
Thus, the radioactive beam from the source 11 passes directly to the patient 9 and does not have to pass through the walls of the tank 3. Also, the controls for the source and the angular position of the tank relative to the patient are not in a pressurized atmosphere, and electric motors may be safely used.
In the embodiment shown in FIG. 2, the therapy apparatus includes a base 21, a post 22 extending upwardly from the base 21, and a housing 15 carried by the base 1 in spaced relation to the post 22. A shaft 16 extends from and is rotatably mounted in the housing 15. The shaft 16 carries a head member 17 from opposite sides of which extend a housing 32 and a counterweight 33. The housing 32 contains a radiation source 31.
An arm 26 extends from the post 22 towards the head member 17 and passes through a rotary seal 27 in a central aperture in an end wall 23a of a cylindrical tank 23. Within the tank 23, the arm 26 carries a stretcher 28 for a patient 29. The end of the stretcher 28 remote from the arm 26 is supported by a rotary bearing 18 carried by the central portion of the adjacent end wall 23b of the tank 23. The central portion of the end wall 23b is secured to the head member 17 and the housing 32 forms a part of the wall of the tank 23. The apparatus is similar in some respects to that shown in U.S. Pat. No. 2,781,454 issued Feb. 12, 1957.
The apparatus also includes means (not shown) in the housing 15 for angularly moving the shaft 16 and therefore adjusting the angular position of the head member 17, housing 32 and source 31, counterweight 33 and tank 23 about the longitudinal axis of the tank 23 relative to the stretcher 28 and patient 29. Means for controlling the source 31 are mounted in the housing 32, and means for pressurizing the tank 23 are also provided. The end wall 230 of the tank 23 has a door 19 for the patient 29 to enter and leave the tank 23.
As with the embodiment shown in FIG. 1 the controls for the apparatus shown in FIG. 2 are not located in the pressurized zone, and the radiation does not have to pass through the walls of the tank.
1. Radiation therapy apparatus including a tank mounted for angular movement about an axis, a patient support within the tank and extending through the tank to the exterior thereof, a second support outside the tank and supporting the patient support, a rotary seal sealing the tank where the patient support passes therethrough, a radiation source, a housing containing the source and carried by the tank such that radiation from the source is directed towards the patient support, means for angularly adjusting the tank, housing and source relative to the patient support, and means for pressurizing the interior of the tank to a pressure above normal atmospheric pressure.
2. Therapy apparatus according to claim 1 wherein the tank is mounted for angular movement about a substantially horizontal axis passing through the tank.
3. Therapy apparatus according to claim 2 wherein the tank is supported by bearings below the tank and engaging the lower portion of the tank.
4. Therapy apparatus according to claim 2 wherein the patient support passes through one end wall of the tank, and an opposite end wall of the tank is secured to a head member rotatably carried by a housing.