EFFECTS OF HEAVY HIGH-ENERGY CHARGED PARTICLES. I. LITERATURE REVIEW OF EFFECTS OF PROTONS, DEUTERONS, AND *cap alpha/-PARTICLES IN MAMMALS WITH A THEORETICAL CONSIDERATION OF THE NEGATIVE *pi/-MESON
A review is presented of reported mammalian studies in this field and investigations with cyclotron- and synchrotron-produced particles ranging up to 3- Bev energy are presented. For physicians, an introductory section is included concerning the physical properties and dosimetric considerations of the particles in order to clarify the pertinent facts essential to an understanding of the nature of the transfer, release, and absorption of energy during the traversal of living mammalian tissues by charged particles. This leads to a theoretical consideration of the future possibilities of the negative pi meson ( pi /sup -/ meson) which will ultimately be studied in the manner in which protons, deuterons, and alpha particles are now being investigated. The pi /sup -/ meson, having a negative charge, will be attracted into the atomic nucleus, and, because of its very strong interaction with nuclear matter, disappears like the photon with creation of an electron pair. Thus the pi /sup -/ meson is transformed upon interaction with nuclear matter into kinetic energy among the various fragments of the disintegrated nucleus. It is suggested that the pi / sup -/ meson may become valuable in medical research, particularly in therapeutic situations requiring a favorable tumor-toentrance dose ratio. In the last centimeter of flight the pi /sup -/ meson should deliver about 100 Mev, yielding a tumorto-entrance ratio of about 30: 1. By comparison, protons of about 130 Mev give a tumor-to-entrance ratio of something like 10.1. The pi /sup -/ beams are produced by directing protons from large accelerators against metal (usually Cu) targets. It is predicted that improvements in accelerator technology and in magneto-optical focusing of proton beams will make pion beams applicable to biological problems within a few years. Proton and deuteron dosimetry are discussed, as a background to a survey of early medical studies with high-energy particles. The particles and energy ranges employed have been protons from 10 to 660 Mev, deuterons from 20 to 400 Mev, and alpha particles from 40 to 910 Mev. Many studies have been devoted to the histopathological effects of irradiation upon the normal brain, pituitary, spinal cord, and to a very limited extent upon the peripheral nerves, lens of eye, and labyrinth, usually with local, but in some instances with whole-body irradiations, These basic studies bear a pertinent relation to certain problems in space medicine. High-energy proton beams have been demonstrated to be useful, with considerable precision, as a neurosurgical tool to ablate selected regions within the brain. Studies on the treatment of animal and human neoplasms, using the advantages that panticle radiation (Bragg- peak effect) have as compared to electromagnetic radiation, are discussed. (BBB)
- Research Organization:
- Bowman Gray School of Medicine, Winston-Salem, N.C.
- NSA Number:
- NSA-18-015826
- OSTI ID:
- 4078663
- Journal Information:
- Archives of Pathology (U.S.) Formerly Arch. Pathol. Lab. Med. Formerly AMA Arch. Pathol. Changed back to Arch. Pathol. Lab. Med., Vol. Vol: 76; Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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PROGRESS REPORT NO. 53: FOR PHYSICS, JUNE 1, 1958 THROUGH AUGUST 31, 1958 AND FOR CHEMISTRY, JUNE 1, 1958 THROUGH OCTOBER 31, 1958
THE POSSIBILITY OF THERAPEUTIC APPLICATIONS OF BEAMS OF NEGATIVE $pi$- MESONS
Related Subjects
ABSORPTION
ACCELERATORS
ALPHA PARTICLES
ANIMALS
BEAMS
BRAIN
CANCER
CHARGED PARTICLES
CYCLOTRONS
DEUTERONS
EFFICIENCY
ELECTROMAGNETIC WAVES
ELECTRONS
ENERGY
EYES
GLANDS
INTERACTIONS
MAN
MEASURED VALUES
MEDICINE
MESONS
NERVOUS SYSTEM
NUCLEI
PAIR PRODUCTION
PHOTONS
PIONS
PITUITARY GLAND
PROTON BEAMS
PROTONS
RADIATION DOSES
RADIATION EFFECTS
RADIOTHERAPY
SPACE
SURGERY
SYNCHROTRONS
TISSUES
TUMORS