ThePhysicsofRadiologychapter61放射物理英文版教学课件

1、RadiobiologyPart OneBME College Sherman Sheen(辛学刚)The Physics of Radiology第1页，共16页。four Rs the repair of sublethal damagerepopulation by surviving cells in the irradiated tissuesredistribution of cells throughout the division cyclereoxygenation of hypoxic cells第2页，共16页。Initial EventThe Passage of th

2、e Charged Particles EFFICIENCY of RADIATION DAMAGE TRACKS of CHARGED PARTICLES 第3页，共16页。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 第4页，共16页。IMMEDIATE RADIOCHEMICAL EFFECT Pro

3、duction of Solvated Electrons and Radicals第5页，共16页。Dependence of Radiation Damage on LET the radiobiological equivalent (RBE) the relative efficiency of killing第6页，共16页。ASSAYS FOR PROLIFERATIVE CAPACITYSURVIVAL CURVES COLONY ASSAY METHODIN VITRO IN VIVO ASSAYS spleen-colony method Limiting dilution

4、assayIn situ第7页，共16页。第8页，共16页。ASSAYS FOR PROLIFERATIVE CAPACITYSURVIVAL CURVES COLONY ASSAY METHODIN VITRO IN VIVO ASSAYS spleen-colony method Limiting dilution assayIn situ第9页，共16页。MATHEMATICAL ASPECTS OF SURVIVAL CURVES SINGLE HIT SURVIVAL CURVE The mean lethal dose (D0) is the dose required to re

5、duce the population of entities from any value N to 0.37 N 第10页，共16页。MULTI-TARGET SINGLE HIT SURVIVAL CURVE 第11页，共16页。THERAPEUTIC RATIO where D2 is the dose that leads to serious complications in 50% of the patients D2/D1and D1 is the dose that gives tumor control inthe same % of patients. 第12页，共16页

6、。RADIOBIOLOGICAL EQUIVALENT (RBE) RBE =Dose from standard radiation to produce a given biological effectDose from the test radiation to produce the same biological effect第13页，共16页。第14页，共16页。CELL CYCLE AND RADIOSENSITIVITY 第15页，共16页。Summary four Rs EFFICIENCY of RADIATION DAMAGE TRACKS of CHARGED PARTICLES IMMEDIATE RADIOCHEMICAL EFFECT ASSAYS FOR PROLIFERATIVE CAPACITYSURVIVAL CURVES MATHEMATICAL ASPECTS OF SURVIVAL