US 2624013 A
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Dec. 30, 1952 H. MARKS X-RAY THERAPY GRID Filed May 27. 1949 INVENTOR. 17 211071 flwrif Patented Dec. 30, 1952 UNITED STATES TENT OFFICE X-RAY THERAPY GRHD Hirsch Marks, New York, N. Y.
Application May 27,1949, Serial No. 95,640
This invention relates to X-ray treatment of malignant tumors, and more particularly to means for the protection of the skin and the underlying normal tissues in the irradiated area from the harmful effects of excessive irradiation, without obstruction of the attainment of an adequate dose of radiation in the deeper lying tumor proper.
In the X-ray treatment of tumors, especially of those of large volume, the excessive absorption of backscatter in the intervening normal tissues hinders the attainment of an adequate dose in the tumor proper because large fields, for physiological reasons, limit normal tissue tolerance, the first impact of the X-rays being on the skin and the underlying normal tissues which would have to be subjected to a harmful overdose of radiation if the malignant process itself is to be reached with an adequate, effective dose of radiation.
The object of the invention is to provide means for the protection of the skin and the underlying normal tissues from the harmful effects of excessive irradiation; a further object of the invention is to provide means to permit longer exposure and exposure of larger areas without harming surface tissues; another object is to permit the reaching of larger or deeper lying tumors with larger doses of radiation than has been possible heretofore because of limited normal tissue tolerance.
The construction of the invention will be apparent from the following specification when considered together with the accompanying drawing, in which:
Fig. 1 is a top view of the invention;
Fig. 2 is a side view of the invention shown in Fig. 1, parts being broken away to show the structure more clearly;
Fig. 3 is another construction embodying the invention;
Fig. 4 is still another the invention.
As shown in Figs. 1 and 2, my invention consists of a sheet or web of metal I, covered on one or preferably both sides with rubber or some other plastic material 2, with a number of openconstruction, embodying .ings 3 arranged in a regular or irregular pattern. In the preferred solution shown in Fig. 1 these openings are arranged in a checker-board pattern, each opening being a square the sides of which are preferably between inch and 1 inch.
As shown, however, in Figs. 3 and 4, the shape of the openings can take other forms, such as circular, oval, and they can be arranged in different, or irregular patterns, depending on the shape and area to be irradiated.
The invention shown serves as a grid to be interposed between the source of X-ray radiation and the tumor to be treated, on the surface of the body of the patient. The layer of lead,
or other metal, lowers the intensity of the beam,
acting at the same time also as filter, absorbing the soft rays in much greater proportion than the hard rays. The skin and normal tissues under the grid thus are safeguarded from over irradiation. Thus, where the irradiation of a surface of 5" by 5" is required, instead of irradiating the entire 25 square inch surface, by applying the grid invented, the actual skin surface exposed would be reduced by approximately 60% to only 10 square inches. Between the number of relatively small skin surfaces directly exposed there would remain an interconnected pattern of unexposed skin surface practically unaffected by radiation. These smaller skin surfaces can easily stand a substantial increase in exposure time without such harmful effects as if the entire, unbroken surface were to be exposed. In the deeper layers, however, especially in the malignant tissues the mechanism of absorption is mainly by recoil electrons, and with the increased exposure time the irradiation will be fully effective.
My invention thus renders possible to reach the malignant tumor across the barrier of the skin and normal tissues with great intensity and yet safeguard to a great extent the normal tissues from the harmful effects of excessive radiation.
I claim, as my invention:
1. A medical instrument for X-ray treatments of the type described, consisting of a layer of lead embedded between two layers of rubber and having a plurality of square openings arranged in alternating order.
2. The method of therapeutical irradiation by X-rays whereby the body surface to be irradiated is subdivided into a plurality of smaller surfaces simultaneously exposed to radiation, said smaller surfaces being surrounded by an interconnected pattern of skin surface shielded from said radiation.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,580,857 Richards Apr. 13, 1926 1,607,140 Wappler Nov. 16, 1926 1,609,222 Taylor Nov. 30, 1926 1,748,403 Wentworth Feb. 25, 1930 1,929,177 Nelson Oct. 3, 1933 2,003,752 Landt June 4, 1935 2,145,686 Dessauer Jan. 31, 1939 2,186,203 Centeno Jan. 9, 1940 2,216,326 Smith Oct. 1, 1940 2,494,664 Lubow Jan. 17, 1950 OTHER REFERENCES Applied X-rays, G. L. Clark, 1940 edition, page 225. (Copy in Patent Oflice Library.)