aajust tne basic quantities and units as demanded by this ditterent
TVnis deciston predates
Jjiscipline.
munoclunal and
the
finding that most human tuuors are
The use of
thus presuaably single cell in origin.
ubsorbed
dose also became standard practice with studies using "Simple ceil”
Here a defined cell population can be
preparations.
“system”
to which an “organ dose”
However,
encountered.
can be applied,
while a uunber of
the
these problems will be detalled
initial objective is simply to
the difficulties associated witn this
cuncepts and quantities apprupriate
concepts.
the
serious concentunal and operational ditticulties were
this communication,
reason for
regarded as
A new approach
application are
to
for HLE,
later in
indicate
the
attempe to use
basic
the old
for LLE that requires Ph
the evaluation of risk from LLE, and its
then presented,
following which tne method of application
is described.
This
is folluved by a more cetailed and
technical
description of
the underlying concepts and methodologies.
A more derafled
critique of the presently used “dosimetric” system Is then given.
The principal pointe of
alter
the estimates of
the proposed approach is aut necessarily to
the risk of exposure as derived using present
methodologies, althougl such 4 result is probable.
that the present Md framework
cast
Rather,
it is
to show
in which LLE risk assessment is presently
ks conceptually inappropriate and misleading, and should be
replaced
by one appropriate for Ph.
that
stated, and then later demonstrated.
This
the absorbed dose PD to an organ can be shown to be proportional
and a. dependent parameter
for
comprising the elements of
parameter particle fluence.
the quantity exposure of
That
is
to,
the cell population
the organ system, expressihle in
terms of
{ts to say, U is proportional
to
the
the
number of primary particles per untt area, which is a descriptor of
the
radiation source, and of the radiation field in which the cell populution
of an organ or other cell population of
typical organ dose-celi
shown on
interest Ls exposed.
response curves shown in Fig.
l,
Thus,
in the
the absorbed dose
the abscissa should be regarded conceptually alchough not
numerically, as
the exposure expressed
in tecms of particle fluence,
~206-
ae
an
e
will act this point simply be
to LLE risk evaluation
to
or
In,
Be Ot icy, anePe
to the need For a new approach
SE aha ant
A fact central
the New Approach
Game o,
The Problem and
4n¢
Phy
Che
Phys ;
Cumor
Say,
Charac
One
my