US 3349242 A
Description (OCR text may contain errors)
Oct. 24, 19 67 c B. BRAESTRUP 3,349,242
APPARATUS FOR RADIATioN THERAPY OF DISEASED TISSUES WITH MINIMUM EXPOSURE TO HEALTHY TISSUES Filed Aug. 7, 1964 2 Sheets-Sheet 1 l9 I I I it:
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APPARATUS FOR RADIATION THERAPY OF DISEASED TISSUES WITH MINIMUM EXPOSURE TO HEALTHY TISSUES Filed Aug. 7, 1964 2 Sheets-Sheet 2 INVENTOR.
ATTORNEYS United States Patent APPARATUS FOR RADIATION THERAPY OF DISEASED TISSUES WITH MINIMUM EX- POSURE T0 HEALTHY TISSUES Carl B. Braestrup, 325 E. 72nd St., New York, N.Y. 10021 Filed Aug. 7, 1964, Ser. No. 388,151 9 Claims. (Cl. 250-54) This invention relates to apparatus for radiation therapy of diseased tissues in the human body such as the irradiation of tumors or cancers through the employment of beams from a radioactive source as, for instance, cobalt 60 or from an X-ray tube, and has for an object to provide for regulatable movements of the source with respect to the patient such that the entire tumor volume will receive an adequate dose with minimum effect on the intervening and/or surrounding healthy tissues and the patient may remain motionless in a comfortable reclining position.
Another object is the provision of apparatus for this purpose that permits precise beam orientation, may be manufactured and installed without excessive expense, is notably compact and un-complicated, readily operated, and affords a maximum of safety to persons associated with the treatment.
Another object is to provide apparatus for this purpose that incorporates a main curved radioactive-sourcecarrying element which may be rotated around its vertical axis and moved rotatively in its own plane around its horizontal axis, either simultaneously or selectively and either manually or automatically, While the patient lies motionless therewithin.
A further object consists in providing certain improvements in the form, construction and arrangement of the various parts, whereby the above stated objects and others inherent in the invention may be efi'iciently attained.
A practical embodiment of the invention is illustrated in the accompanying drawings, in which FIG. 1, represents a vertical sectional view, partly in elevation, of the complete apparatus, with the patient shown on a usual support in position for treatment; and
FIG. 2,.represents a similar view at a right angle to FIG. 1.
In brief summary, the invention contemplates apparatus such as has been indicated in the above recited objects, and which it is thought unnecessary now to repeat as the same will be further clarified in the detailed description of the drawings, to follow.
The major objective in irradiation of a diseased portion of the human body has been the accomplishment of imparting an adequate dose of radiation to the volume of tissue under treatment without injurious eifect or effects upon intervening and/or surrounding tissues. A number of solutions of this problem have been advanced with more or less success, and usually accompanied by certain drawbacks, such, for instance, as the employment of a plurality of radiation beams successively entering the body at diflerent portals though all directed at the diseased volume; rotation or oscillation of the patient; the socalled swinging pendulum irradiation; the spiral motion convergent beam method; and the movement of the radioactive source around two axes perpendicular to and intersecting each other. As the diseased tissue generally is deep-seated in the body it is necessary to employ large doses of penetrating radiation in order to cause sufiicient efiect upon the volume needing treatment due to the fact that a large portion of the energy of the beam of radiation will be absorbed by the intervening sound or healthy tissue through which the beam must pass before reaching its target, with consequent danger of serious injury to the healthy tissue.
The result of the foregoing brief recital of conditions involved in this branch of radiology has led to a feeling or conclusion that the preferred procedure utilizes the movement of the apparatus to cause the beams to impinge upon different areas on the surface of the patients body, known as ports of entry and then converge upon the diseased tissue. The present invention thus is directed to an improved apparatus for this purpose. The inherent simplicity of the invention and space requirements, its re duced weight, and ease of adjustment are its principal advantages.
Turning now to the drawings, a curved element such as a section of a ring or annulus composed of a suitable metallic substance and marked 1 carries the housing, indicated by 2, of the source of radiation 3, which may be, for instance, a radioactive isotope of cobalt, Co, or an X-ray tube, that is secured to the ring section by a pair of screw bolts 4, 4, and is fitted with a collimator or aperture 5, for the emergence or projection of the beam of radiation. It is deemed unnecessary either to show or describe the source in detail as this is well within the knowledge of those ordinarily skilled in this art and is illustrated and explained, e.g., in United States Patent No. 2,781,454, issued Feb. 12, 1957.
On the portion of the ring section opposite the source housing is mounted a combination counter-balance and beam shield marked 6 which is composed of lead or its equivalent. This shield intercepts the primary beam irrespective of the beam direction.
The ring section 1 can move rotatively around its horizontal axis on bearings 7, 7, which are mounted on a turntable 8, and this curved element 'also carries a circumferential rack 9 that mates with a spiral gear 10 driven by an electric motor 11 mounted on the turntable 8 which rides on a circular set of balls 12 fitted in a base 13.
It is thought to be clear from the foregoing that actuation of the motor 11 will serve to rotatively move the ring section 1 around its horizontal axis, while the turntable 8 permits rotation of the ring section 1 around its vertical axis. Each or both of these motions may be initiated and controlled manually or automatically, and the motions may be oscillatory by the use of reversible motors. The electric set-up for accomplishing this is so well understood by those ordinarily versed in the electrical art that it is deemed unnecessary'either to show or describe the same, the mere stating of a desire for automatic operation with either or the above named motions being sufiicient for its accomplishment.
It should be noted that the heavy shield 6 is of a weight adequate to balance the weight of the source housing 2.
The patient to be treated is shown in broken lines in the drawings and marked P while the diseased volume of tissue is denoted by D.
A treatment couch upon which the patient reclines is denoted by 14, and is supported in a well known manner by a structure that comprises a head piece 15 which is mounted on a pillar 16 set in a base 17 which houses suitable mechauism for elevating or lowering the pillar and head piece, a handle 18 serving to control the said mechanism. The couch top rests on rollers 19 for adjustment in line with the longitudinal axis of the patient. As this structure is conventional and, of itself, constitutes no part of the present invention, further description or illustration is regarded as superfluous, but it may be added that the top of the couch 14 should be composed of low density material, e.g., aluminum or plastic, which otters a minimum of attenuation to the beam of radiation, and that the structure supporting the couch is spaced from the beam.
In preparing for a treatment the supporting means for the couch 14 should be adjusted so that the center ofthe diseased tissue volume D is at the intersection of the imaginary horizontal axis of rotative movement of the ring section 1 in its own plane and the central ray of the beam of radiation.
The heavy shield 6 not only counter-balances the heavy source housing, as previously noted, but also serves to attenuate the radiation that has traversed the patient and thus reduces the shielding requirements of the treatment room.
The variety of motions attainable with this apparatus offers practical means for fulfilling the objects hereinabove recited, and especially the possibility of applying desired doses to the diseased volume of tissue with minimum injury to the intervening or surrounding sound and healthy tissues.
It is thought that no further description of the mode of operating this apparatus is needed, because the same and its flexibility will be clear to the medical profession from the explanation already made; but I desire it to be understood that various changes may be made in the form, arrangement, construction and material of the several parts or elements, without departing from the spirit or scope of the invention, and hence do not intend to be limited to details herein shown or described except as the same may be included in the claims or be required by disclosures of the prior art.
What I claim is:
1. Apparatus for radiation therapy comprising, an arcuately curved element having vertical and horizontal axes the latter being disposed perpendicularly to the plane of the said element, a source of radiation fixed near one end of the curved element, a beam shield attached to said element opposite the said source, means for imparting rotative motion to said element around its horizontal axis, means for imparting rotative motion to said element around its vertical axis, a base in alignment with the said source and shield, and means for mounting said curved element on said base.
2. Apparatus as defined in claim 1, which also includes a turntable upon which the curved element is mounted, said turntable having bearings on its upper surface supporting the curved element for motion around its horizontal axis.
3. Apparatus as defined in claim 2, which also includes an electric motor mounted on the turntable provided with a gear on its drive shaft, and in which the said curved element is fitted with a curved rack meshing with said gear and adapted to impart motion to the curved element around its horizontal axis when the motor is actuated.
4. Apparatus as defined in claim 3, in which the turntable is rotatably mounted on a base to adapt the curved element for rotary motion around its vertical axis.
5. Apparatus as defined in claim 1, in which the shield is composed of material adapted to absorb radiation beams, such as lead.
6. Apparatus as defined in claim 1, in which the curved element is a semicircle.
7. Apparatus for radiation therapy which comprises, a curved element in the form of a section of a circle disposed in a vertical plane, a source of radiation fixed at the upper end of the said element, a collimator operatively associated with said source of radiation and adapted to direct the beam of radiation in said vertical plane toward the center of said circle, a weighted shield fixed on the curved element at a point diametrically opposite the source of radiation, a turntable beneath said shield, bearings upon said turntable supporting the curved element for motion in its own plane around its horizontal axis, a rack on the lower portion of the said curved element, a motor driven gear meshing with said rack, and a base supporting the turntable provided with bearings engaging the turntable for adapting it to turn and rotate the curved element around its vertical axis.
8. Apparatus as defined in claim 7, which also includes means for supporting a patient in a reclining position with the diseased portion between and in line with the collimator and the shield.
9. Apparatus as defined in claim 8, in which the means for supporting a patient is provided with a top composed of low density material that offers a minimum of attenuation to the beam of radiation.
References Cited UNITED STATES PATENTS 2,781,454 2/1957 Green et al 25091 2,890,349 6/1959 Huszar 250-91 3,082,322 3/1963 Koerner et al 250-615 ARCHIE R. BORCHELT, Primary Examiner.
WALTER STOLWEIN, RALPH G. NILSON,
Examiners. A. L. BIRCH, Assistant Examiner.