Biomedical Engineering Reference
In-Depth Information
8.
P
LANNING
M
ANUALLY
Introduction ........................................................................................157
Planning by Hand...............................................................................158
Developing a manual plan.....................................................................160
Environmentally Friendly Dose Disposal ..........................................164
Integral dose ..........................................................................................165
Impact of treatment approaches on integral dose .................................165
Where to dispose of the dose? ..............................................................167
A lot to a little or a little to a lot? ..........................................................167
The influence of tissue architecture ......................................................168
Uncertainty in the Dose Distribution .................................................170
Calculation of uncertainty.....................................................................171
Display of uncertainty ...........................................................................172
Uncertainty in quantities depending on the dose distribution ..............174
The Patient's-Eye View ......................................................................174
Diagnosis and choice of treatment modality.........................................174
The patient's role in risk management..................................................174
The patient as monitor of the treatment ................................................175
I
NTRODUCTION
Finally we have reached the point at which we can discuss the actual
planning of a treatment. The preliminaries have been taken care of:
we have the imaging studies and the needed volumes of interest
delineated; we know how a single photon beam is constructed; and
we have the planning aims in front of us. Then, too, we know how to
evaluate any plan we devise, and how to compare it with alternative
plans. Let the fun begin!
There are two basic approaches to developing a plan. The first is
what I call
manual planning
. This is by no means all manual, since
computers and graphical displays are heavily used. What is “manual”
is the way in which the plan is assessed as it is iteratively improved.
The assessment uses what I called “expert inspection” in Chapter 6,
and is a largely subjective process which is based on a review of a
very large number of computed quantities. Manual planning usually,
but not always, has as its goal the development of uniform-intensity
radiation therapy.
157
