Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2559793 A
Publication typeGrant
Publication dateJul 10, 1951
Filing dateJan 27, 1949
Priority dateJan 27, 1949
Publication numberUS 2559793 A, US 2559793A, US-A-2559793, US2559793 A, US2559793A
InventorsAlexander Pregel
Original AssigneeCanadian Radium And Uranium Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Beta irradiation method and means
US 2559793 A
Images(1)
Previous page
Next page
Description  (OCR text may contain errors)

July 10, 1951 A. PREGEL 2559393 BETA IRRADIATION METHOD AND MEANS Filed Jan. 27. 1949 INVENTOR Alexander pregel ATTORNEY good results.

Patented July 10, 1951 BETA IRRADIATION METHOD AND MEANS Alexander Pregel, New York, N. Y., assignor to' Canadian Radium and Uranium Corporation, New York, N. Y., a corporation of New York Application January 27, 1949, Serial No. 73,080

5 Claims.

This invention relates to the use of pure beta irradiation or substantially pure beta irradiation for therapeutic purposes, and more particularly for ophthalmic purposes.

It has heretofore been proposed to use a radon applicator for the treatment of certain lesions of the eyelids and anterior ocular segments, and such treatment has been extensively tested at the Eye Department of the Cleveland Clinic with (Cleveland Clinic Quarterly, April, 1946). The radon applicator has required the use of a 250-275 millicurie radon glass bulb applicator, having a diameter of 5 millimeters and a wall thickness of one millimeter. This radon technique could be duplicated only in a few large medical centers.

Tests have shown that the elimination of the gamma ray radiation of the radon applicator is a great advantage to the physician and the patient, and that pure beta rays are effective for treating many ophthalmic conditions.

By eliminating the gamma ray radiation, the physician is not endangered by continuous exposure to penetrating gamma rays, and no essential radiation reaches the crystalline lens of the patient. Also, an applicator which emits substantially no gamma rays can be easily stored, because one millimeter of lead blocks out all essential radiation.

The improved applicator and the tests and uses thereof are described in the Mississippi Valley Medical Journal and Radiologic Review vol. '70, pp. 71-72 (March, 1948) and in the November 1948 issue of First Annual Radiation Therapy Number of the Mississippi Valley Medical Journal and Radiologic Review.

As stated therein, the use of radium element was tried, but it was not possible to concentrate enough of radium element in a small applicator to give the treatment rapidly.

Radium element disintegrates to produce radon gas, which disintegrates to produce a series of disintegration products.

Radium D disintegrates to produce radium E,

which has an atomic weight of 210, an atomic number of 83, and a half-life of five days. Radium E emits beta and gamma rays. The maximum energy of the beta rays emitted by radium E is about 1.17 Mev.

Radium E disintegrates to produce radium F, also designated as polonium, which emits alpha rays, with a feeble emission of beta rays.

As one example, the improved applicator is a circular silver foil or plaque, whose radio-active diameter is 5.6 millimeters and whose thickness is one millimeter.

This disc-shaped plaque has 25 square millimeters of active surface area. This plaque is provided with a filter or Window of aluminum, whose thickness is 0.05 millimeter. This plaque fits closely in the recess of a holder body which is made of Monel metal. As described at page 444 of the 1942 edition of The Condensed Chemical Dictionary published by Reinhold Publishing Corporation, Monel metal contains 60%-70% nickel; 25%35% copper; 1%-3% iron; 0.25%-2% manganese; 0.02%-1.5% silicon; 0.3%-0.5% carbon.

This plaque contains 10 millicuries of radium D, although variable concentrations of radium D may be used.

A 10 millicurie applicator of this size contains 800% of the amount of radioactive material per squire millimeter of surface area, as compared with a full-strength radium-element plaque, in which the radium-element has an atomic weight of 226, and an atomic number of 88.

The aluminum filter can be replaced by other filtering material of low filtering density, such as mica. Monel metal can also be used.

The density of this preferred aluminum filter is about 16% of the density of a filter of Monel metal which has a thickness of 0.1 millimeter, thus greatly increasing the effective beta ray output.

. Tests have shown that a few feeble gamma rays are emitted by the improved applicator. Such tests have shown that this applicator is a source of substantially pure beta radiation. The electro-magnetic radiation consists mainly of a feeble, low energy gamma radiation from radium D, and from Bermsstrahlung, namely, from the continuous X-rays which are produced by the interaction of the beta rays of the radium E with the Monel metal backing of the applicator. The maximum ionization of these gamma rays and X-rays is less than one-tenth per cent of the ionization due to the emitted beta rays.

Since more than 99.9 of the total ionization produced by all the radiations of the applicator is produced by beta rays, the presence of the very feeble gamma radiation having a quantum energy of only 0.047 Mev. is therapeutically unimportant, and of no biologic effect in comparison with the 0 energetic beta rays of radium E, which have a maximum energy of about 1.17 Mev.

The beta ray output which is produced substantially Wholly by the high energy beta rays of radium E, averages about 11,000 equivalent lr'ltoentgens (rep) of surface beta ray dosage per our.

Since radium E is in equilibrium in the applicator with radium D, the beta ray activity decreases with a half -period of 22.2 years, which is characteristic of radium D. The filter completely absorbs the soft beta radiation of radium F (polonium) Substantially only the penetrating beta rays of radium E emerge from the applicator.

These beta rays which are thus emitted, have the same qualities as gamma rays, in selective tissue destruction, but penetrate only 3-4 millimeters of tissue, thus making it possible to treat superficial conditions without endangering the lens, and preventing possible formation of a cataract.

The greatest effect of these emitted beta rays is superficial, because their effect is inversely proportional to the square of the distance from the source.

Favorable tests have been made with the improved applicator for various eye conditions, such as (1) corneal scars, except those which are calcified or very dense; (2) corneal vascularizations from any cause; (3) papillomas of the lids; (4) hemangioma; (5) vernal conjunctivitis; (6) pterygium, if not too dense.

By eliminating or substantially eliminating gamma rays, it is possible to use a larger dosage of the beta rays.

When using the 10 millicurie applicator, a 4-5 minute contact is used in treating vascularizations of the cornea, and the treatments may be repeated at intervals of 2-4 weeks.

The applicator should be placed as close to the lesion as possible, preferably in contact with the tissue. I

Fig. 1 is a diagrammatic cross-section, not to scale, of one embodiment of the improved applicator;

Fig. 2 is a front end-view.

Fig. 3 is a rear end-view.

This applicator comprises a cylindrical body I, which is made of Monel metal. At its front, said body I has a cylindrical recess or cavity, whose diameter is 5.6 millimeters and whose depth is one millimeter.

A silver foil or plaque 2 fits snugly in this recess. The thickness of the annular wall la of said recess is 1.7 millimeter.

This disc-shaped foil or plaque 2 contains 10 millicuries of radium D, although this concentration may be varied. A filter 3, made of aluminum, and having a thickness of 0.05 millimeter, abuts the front annular face of wall la and the front wall of the disc-shaped foil or plaque 2.

This filter 3 is held in place by the fiange 4a of a collar 4, which is made of Monel metal, and which has a thickness of 0.1 millimeter. The flange 4a is of minimum diameter. Said collar 4 fits snugly on body I.

The initial length of the cylindrical body of collar 4 exceeds the length of body I. After collar 4 has been applied, it is soldered to body I at the rear face 5 of body I. The collar 4 is then cut transversely to be flush with rear face 5. Said rear face 5 has a tapped recess 5a, and the threaded end of a handle, not shown, may be fixed detachably to the internally threaded wall of recess 5a.

The active diameter of the plaque 2 in the finished applicator is substantially 5.6 millimeters, with an active surface of substantially 25 square millimeters.

The improved applicator therefore has a radioactive source which consists substantially of radium D in equilibrium with radium E, so as to deliver substantially constant beta rays over a long period. While some polonium is produced in the applicator, its effect is insignificant.

The filter preferably blocks the alpha rays which are emitted by the polonium which results from the disintegration of the radium E.

The thin carrier 2 is permeable to the beta rays of radium E, so that the entire mass of carrier 2 emits the beta rays of radium E.

The parent radium D is optionally and preferably uniformly incorporated in the entire mass of the carrier 2.

The length of body I is about 3 to 4 inches, so that when solder is applied at rear face 5, the heat of the soldering operation will not affect the thin carrier 2 or the thin filter 3.

While element 3 may be a window, each element 3 is preferably and optionally imperforate, in order to block the undesired radiation.

The radium D may be deposited upon the surface of the carrier 2, as an alternative to impregnating carrier 2 with the radium D.

Electro-deposition may be used for depositing the radium D upon the surface of carrier 2.

For this purpose, a salt of radium D and a salt of lead are dissolved in water, in order to provide an electrolytic bath. I can use the nitrate or chloride of radium D, and the nitrate or chloride of lead.

I'thus produce a co-deposit of radium D and lead by electrolysis upon the surface of the metal carrier 2, which is preferably the cathode.

This method of simultaneously electro-depositing radium D and lead on a metal carrier is Wellknown per se, so that the details thereof, such as the proper pH of the electrolytic bath, are not described herein.

I have. described preferred embodiments of my invention, but numerous changes and substitutions and omissions and additions can be made without departing from its scope.

I claim:

1. An ophthalmic applicator which has radioactive material which consists substantially wholly of radium D and radium E and radium F, said applicator having filter means which are permeable substantially only to beta rays emitted at the energy level of the beta rays emitted by radium E.

2. An ophthalmic applicator according to claim 1, in which said betay ray output is substantially 11,000 equivalent Roentgens (rep) of surface beta ray dosage per hour.

3. An ophthalmic applicator according to claim 1, in which said radium E and radium F are the successive derived disintegration products of radium D originally incorporated in said applicator, said derived radium E being in equilibrium with said original radium D.

4. A method of treating living eye tissue which consists in applying substantially only the beta rays emitted substantially only by radium E to said living tissue, the maximum energy of said emitted beta rays being substantially 1.17 Mev.

5. An ophthalmic applicator which has a radio-active source which consists substantially Wholly of radium D, radium E and radium F, said radium E and radium F being the disintegration 5 products of original radium D of said source, said source originally having at least substantially 0.4 millicurie of radium D per square millimeter of active surface area, said applicator having a filter which is permeable substantially only to the beta rays emitted substantially only by radium E, the maximum energy of said emitted beta rays being substantially 1.17 Mev.

ALEXANDER PREGEL.

REFERENCES CITED The following references are of record in the file of this patent:

OTHER REFERENCES Atomic PhysicsUniversity of Pittsburgh Staff Members-1937-pages 234-241-Pub1ished by John Wiley & Sons, Inc. New York, New York.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US839061 *Feb 23, 1905Dec 18, 1906Henri FarjasApparatus for application of salts of radium.
US1654888 *Mar 25, 1926Jan 3, 1928Francis KingOphthalmic massage instrument
US2326631 *Aug 15, 1941Aug 10, 1943United States Radium CorpRadioactive unit and method of producing the same
AT81068B * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2797333 *Jul 24, 1953Jun 25, 1957Armour Res FoundChi-ray source
US2964628 *Feb 1, 1956Dec 13, 1960Ohmart CorpRadiation source for density responsive apparatus
US2992980 *May 16, 1957Jul 18, 1961Exxon Research Engineering CoApparatus for radiation promoted processes
US5141487 *Dec 12, 1989Aug 25, 1992Liprie Sam FAttachment of radioactive source and guidewire in a branchy therapy source wire
US5351689 *Aug 26, 1993Oct 4, 1994University Of GuelphUsing sodium iodide spectrometer to determine the mineral concentration in bone to monitor osteoporosis
US7070554 *Jan 15, 2003Jul 4, 2006Theragenics CorporationBrachytherapy devices and methods of using them
US7220225Apr 20, 2006May 22, 2007Retinalabs, Inc.Intraocular radiotherapy treatment
US7223225Nov 18, 2005May 29, 2007Retinalabs, Inc.Intraocular radiotherapy treatment for macular degeneration
US7276019Mar 8, 2005Oct 2, 2007Retinalabs, Inc.Ophthalmic treatment apparatus
US7563222Sep 15, 2005Jul 21, 2009Neovista, Inc.Methods and apparatus for intraocular brachytherapy
US7744520Feb 11, 2005Jun 29, 2010Neovista, Inc.Method and apparatus for intraocular brachytherapy
US7803102Nov 7, 2006Sep 28, 2010Neovista, Inc.Methods and apparatus for intraocular brachytherapy
US7803103Nov 15, 2006Sep 28, 2010Neovista Inc.Methods and apparatus for intraocular brachytherapy
US7951060Jun 2, 2010May 31, 2011Neovista, Inc.Methods and apparatus for intraocular brachytherapy
US8100818Jul 19, 2007Jan 24, 2012TDH Partners, Inc.Beta radiotherapy emitting surgical device and methods of use thereof
US8292795Sep 22, 2010Oct 23, 2012Neovista, Inc.Methods and apparatus for intraocular brachytherapy
US8353812Jun 3, 2009Jan 15, 2013Neovista, Inc.Handheld radiation delivery system
US8365721Aug 27, 2010Feb 5, 2013Neovista Inc.Methods and apparatus for intraocular brachytherapy
US8430804Jan 7, 2009Apr 30, 2013Salutaris Medical Devices, Inc.Methods and devices for minimally-invasive extraocular delivery of radiation to the posterior portion of the eye
US8597169Jan 16, 2013Dec 3, 2013Salutaris Medical Devices, Inc.Methods and devices for minimally-invasive extraocular delivery of radiation to the posterior portion of the eye
US8602959May 19, 2011Dec 10, 2013Robert ParkMethods and devices for delivery of radiation to the posterior portion of the eye
US8608632May 19, 2011Dec 17, 2013Salutaris Medical Devices, Inc.Methods and devices for minimally-invasive extraocular delivery of radiation and/or pharmaceutics to the posterior portion of the eye
US20080166297 *Dec 1, 2005Jul 10, 2008Dong Wha Pharm. Ind. Co., Ltd.Radionuclide-Chitosan Complex Having an Improved Stablilized Gelatin in Administering Them to the Body and Their Preparation Method
EP1997532A1May 27, 2008Dec 3, 2008Seoul National University HospitalOphthalmic applicator for treatment of pterygium or glaucoma using 32-P alone or in combination with 103-Pd
Classifications
U.S. Classification600/1, 250/496.1, 310/301, 600/7
International ClassificationG21G4/06, G21G4/00
Cooperative ClassificationG21G4/06, A61N2005/1089, A61N5/1017
European ClassificationG21G4/06, A61N5/10B4M