a
Next,
the phantom must recurd separateiy for every uisieete mbe
phantom cell,
the magnitude of
must provide
the
tne distribution of
cell TCV's,
obtainable
the energy deposited.
or
the
cell
the magnitudes of
doses.
for any give. exposure
This
Chest
.
That is to savy,
Ae
the enecsy uepostts in
distribution of
Co 4 Singie
ato
tvte of
cell
doses
must
be
rcadiatton, ot any
mixture.
THe electronic ohantom can be sade
eet]
doses neatly
in order of
analogue of what is
Co arringe
tne stochastic cell
increasing magnitude. Thus we have the exacce
commonly used
in pharc.acolopy and
series of cell doses, wotch io principle pernits us
toxtcolosy--a graded
cto develop a function
foc the (fractional) number sf hit cells cthac will cespond quanctally, act
each value of cell dose.
This {ts the cell analogue of the “organ
dose-organ response” curve,
probability
thac,
we
1s equal
to
the conditional
if hic, ana with a dose of a given magnitude, a cell wilt
tespond quantally.
points.
This fraction
Such curves are now available,
thus have
three probabilities
for several cellular
to Se evaluated,
1)
2na
tne
probability that an exposed cell will be hit, 2) that the ure ceil will se
of a given cange with a given gaize,
these probabilities
fraction of
and 3} will respond quantally.
trac pernit us
those exposed
to determine,
‘
re eens d
wee GAINS yy
*
SNE
To.
LUD
yo
seeds
radiation of a single quality.
neither
the mean nor
the area under
are hit,
series
that
of
effectiveness
the
Note
shown
is
Cee
the
the
function of
CApvsGTes, 20
2 are
44. Lor 4a
the exposure tacreases,
the distributlons chanzes--it
f.e.,
that
In Fiz.
cell doses fron stocnastic
that as
ts only
the number of exposed cells
that
these distributions represent a graced
S-shaped
function), a relationship
quantal response as a
distribution
maximum of
increases.
Also
ak
tote
the distributions,
doses.
the above stitements.
three distributions of
~~ e
for a given exposure,
that will respond quantally.
An example will help to clarify
shown schematically
I: is
curve,
that provides
the celi dose.
ts multiplied by the HSEF,
an HSEF (Chit-size
[2
the probability of a
the cell dose
the result will te the
correspondingly-mazned smaller distribution,
under
area
che single ana ceteruinaias enc
undeec
the smalier distribution provides
che larger one.
point in quantitative epidemlology or risk assessment,
of
those expused during a given exposure,
1.@2.,
The
the fractéon
that will respond quantally.
phantom”,
is such more
tnan the analogue of an organ phantum.
than simpaly determine a dose
catner
to a single organ o¢ organism, provides not
5
SOC Tu S4
It,
a
As will be expanded on later, what has b‘een termed avove a “cell