hePhysicsofRadiology-chapter6-1 放射物理 英文版 教学.ppt

Radiobiology Part One,BME College Sherman Sheen(辛学刚),The Physics of Radiology,four Rs,the repair of sublethal damage,repopulation by surviving cells in the irradiated tissues,redistribution of cells throughout the division cycle,reoxygenation of hypoxic cells,Initial EventThe Passage of the Charged Particles,EFFICIENCY of RADIATION DAMAGE,TRACKS of CHARGED PARTICLES,DISTRIBUTIONS IN SPACE of ENERGY RELEASES,LINEAR ENERGY TRANSFER (LET),the electron tracks,0.25 keV/m,an alpha particle,250 keV/m,SPECTRUM OF LET VALUES,velocity,charge,IMMEDIATE RADIOCHEMICAL EFFECT,Production of Solvated Electrons and Radicals,Dependence of Radiation Damage on LET,the radiobiological equivalent (RBE),the relative efficiency of killing,ASSAYS FOR PROLIFERATIVE CAPACITY SURVIVAL CURVES,COLONY ASSAY METHODIN VITRO,IN VIVO ASSAYS,spleen-colony method,Limiting dilution assay,In situ,ASSAYS FOR PROLIFERATIVE CAPACITY SURVIVAL CURVES,COLONY ASSAY METHODIN VITRO,IN VIVO ASSAYS,spleen-colony method,Limiting dilution assay,In situ,MATHEMATICAL ASPECTS OF SURVIVAL CURVES,SINGLE HIT SURVIVAL CURVE,The mean lethal dose (D0) is the dose required to reduce the population of entities from any value N to 0.37 N,MULTI-TARGET SINGLE HIT SURVIVAL CURVE,THERAPEUTIC RATIO,where D2 is the dose that leads to serious complications in 50% of the patients,D2/D1,and D1 is the dose that gives tumor control in the same % of patients.,RADIOBIOLOGICAL EQUIVALENT (RBE),RBE =,Dose from standard radiation to produce a given biological effect,Dose from the test radiation to produce the same biological effect,CELL CYCLE AND RADIOSENSITIVITY,Summary,four Rs,EFFICIENCY of RADIATION DAMAGE,TRACKS of CHARGED PARTICLES,IMMEDIATE RADIOCHEMICAL EFFECT,ASSAYS FOR PROLIFERATIVE CAPACITY SURVIVAL CURVES,MATHEMATICAL ASPECTS OF SURVI