a eae eee wre -— we ohysycians, who ad had atm no . eet wee dtrect way gE ae ee went te determining «nat tissues were recelving from a give exposure. he ke ee che That is ~~ « tutor “3 wee of nersil to sav, ome Must use a “cell phantom” tf one wishes to estimate the dose to a Living cell. we ust outline cell phantom. the requirements ana lecessary charactertstics of However, only the dose 4avptoach to tne Ladividual urpan of the problem from the Ch, statistics standpoints. radiation enersy (L.@., due to This tlisues Cumuoc of taterest, ~2 must 1.e., epidentlolugteal and acciceur is, of course, tanes plac2 because any transfer of only 45 a result of s7sena bet.zen 2 ch:ryved the (fractional) number of cells nit. Also, because 1.e., the “nit slze” or “celi dose”. magnitude of the cell cose varies greatly from cell trom zero to the maximum amount of kinetic energy carried by the dose, to be Thus <e the TCY in separate, discrete amounts, we need also the amount of energy deposited, Thus regiiced al particle and a target-containinsg volume (TCV) within the cell. energy is deposited tn unitke ia an “td* rode amd to random processes) encounters or collisions first need, with LLE, Sucn a in so dulnhg we cust Be ever mindful that, the eicly (and peesent) physiclans who operated Thus relevant, must be registered The tuo cell, anc ranges in tne particle. [ndivideals ace tre level of bDfLological organization at which the initatioa of interest occurs. that, while with KLE oniy The imporctunc conclusion is the response cf the one physical quantity organ dose is cequired tor risk evaluation, witn LLE least The and two fodependent quantities First requirement, cosed during electronic. any given many hits per cell can register a to > total of x f2 verfod Te requires the shect recovery be recorded hits rcequtrea, - a.e exposure It can then have are wT iD at during (L.e., that tiie needed in order that tf a number of phantom cells au exposure Cine t, then a cecovering cell will also register x hits during a time of the phantom will, with use of with the first of at least eoidemtological evaluation, numerically to the tyvo xt). Tr the appropriate scaling factor, probabilities! namely, probability the the that a needed nunber cell will of in hits be hit, provide us principle per cell, doses, for equal ana tnrured. =o ; The number in a group expected to respond quantally attec a alven exsosuce provides the numerical probability that such a response will accur. Thus, the term probability will be used interchangeably with tne terus “rraction’ or “proportion” of equaily dosed quantal responders and the term “risa” will be used fLaterchangeably sith the oruportics or inefdence of stuchastically, and thus unequally-dosed quantal respunders. 59071493