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Table 1: Results of comparison between simulation frames
and CT slice acquired during free breathing.
Frame number Mean of grey levels
0-5 17
10-20 16
25-60 15
65-70 16
75-80 17
85-90 18
95-101 19
4 CONCLUSIONS
The here proposed technique allows to estimate the
lung tumor morphology during patient’s free-
breathing by acquiring CT slice at forced expiration
and forced inspiration. The technique could give an
important contribution for the improvement of
radiation treatment planning, always considering the
set up margin, which allows for the uncertainties on
treatment reproducibility. In order to define the area
to be irradiated during a particular phase of the
breathing period, the cancer area in the simulation
frame corresponding to this phase has to be
considered as target: this allows the absence of
motion shadings. The present work represents only a
first stage study which could allow to deliver a high
dose to the tumour while minimizing the dose
delivered to the surrounding healthy tissue, though
further researches with more subjects are still needed
in order to test the accuracy of the presented
methodology.
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