RBE for lung and cord

Journal Article · Wed Dec 01 04:00:00 EST 1982 · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

DOI:https://doi.org/10.1016/0360-3016(82)90552-1· OSTI ID:5239043

Hornsey, S

The sparing effect of fractionation of neutron dose is very small for late damage in tissues. This is seen in the almost flat isoeffect curve for damage to skin, CNS and to lung. This means that differences in the RBE curves for these tissues are determined by differences in the slopes of the photon isoeffect curves. The relevant slopes of the photon isoeffect curves giving the exponent of N in the Ellis formula are 0.24 for subcutaneous tissue, 0.27 for lung damage and 0.38-0.45 for damage to spinal cord, while the exponent for N for neutrons for these tissues is 0.04 for subcutaneous tissues and zero for lung and spinal cord. The slopes of the RBE curves for lung and cord or for skin and cord when RBE is plotted against dose/fraction of photons are significantly different, and the RBE at a ..gamma.. ray dose/fraction normally used in therapy of about 2 Gy, is significantly higher for spinal cord than for lung or skin. The sparing of damage by extending overall treatment time for both lung and CNS is small for X or ..gamma..-irradiation. For neutron irradiation the sparing is similar to that with photons for the CNS but is much less with neutrons than with photons for the lung. This is because different mechanisms are responsible for this type of sparing of damage in the two tissues. In lung, slow repair is involved while in the spinal cord, the sparing is related to the slow cell proliferation.

• Research Organization: Hammersmith Hospital, London
• OSTI ID: 5239043
• Journal Information: Int. J. Radiat. Oncol., Biol. Phys.; (United States), Journal Name: Int. J. Radiat. Oncol., Biol. Phys.; (United States) Vol. 8:12; ISSN IOBPD
• Country of Publication: United States
• Language: English

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62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BARYONS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BODY
CELL PROLIFERATION
CENTRAL NERVOUS SYSTEM
DELAYED RADIATION EFFECTS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
FRACTIONATED IRRADIATION
GAMMA RADIATION
HADRONS
IONIZING RADIATIONS
IRRADIATION
LUNGS
MAMMALS
MEDICINE
MICE
NERVOUS SYSTEM
NEUTRONS
NUCLEAR MEDICINE
NUCLEONS
ORGANS
RADIATION EFFECTS
RADIATIONS
RADIOLOGY
RADIOTHERAPY
RBE
RECOVERY
REPAIR
RESPIRATORY SYSTEM
RODENTS
SIDE EFFECTS
SKIN
SPINAL CORD
THERAPY
VERTEBRATES
X RADIATION