Biological effects of negative pions

Conference · Thu Jan 01 04:00:00 EST 1976

DOI:https://doi.org/10.1016/0360-3016(77)90272-3· OSTI ID:7316362

Raju, M R; Amols, H I; Bain, E; Carpenter, S G; Dicello, J F; Frank, J F; Tobey, R A; Walters, R A

Most pion radiobiological work in the past was done at low dose rates using biological systems sensitive to small doses. Biological effects at the beam entrance were found to be nearly the same as conventional radiations, although some reports have indicated a higher RBE. LET distribution at the peak of a nearly monoenergetic pion beam is not much different from fast neutrons; therefore, one would expect similar biological responses, and the results are consistent with this hypothesis. The RBE at the peak for a nearly monoenergetic pion beam is significantly higher than at the entrance. The RBE peak/RBE plateau ratio is decreased with increasing width of the peak. The OER (approximately 1.6) at the peak for a nearly monoenergetic pion beam is also similar to fast neutrons and is expected to increase with increasing width of the peak. No OER data for broad peaks relevant to therapy are available. Preliminary measurements on radiosensitivity variation as a function of cell cycle indicate that there is a slight reduction in variation at the plateau, compared to X-rays, and a significant reduction at the narrow peak.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7316362
• Report Number(s): LA-UR-76-2529; CONF-760946-5
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
655003* -- Medical Physics-- Dosimetry
BOSONS
DEPTH DOSE DISTRIBUTIONS
DOSIMETRY
ELEMENTARY PARTICLES
ENERGY TRANSFER
HADRONS
LET
MESONS
OXYGEN ENHANCEMENT RATIO
PION DOSIMETRY
PIONS
PIONS MINUS
PSEUDOSCALAR MESONS
RADIATION DOSE DISTRIBUTIONS
RBE
SPATIAL DOSE DISTRIBUTIONS