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Paris system calculation (cont.)
3.
Calculate the doserate at each Basal Point
4.
Calculate the mean of the individual Basal Point
Doserates (known as the Basal Doserate)
5.
Calculate 85% of the Basal Doserate (known as
the Reference Doserate). This isodose was chosen
for clinical reasons – best compromise
between
good coverage and keeping hotspots small
6.
Calculate the treatment time based on the Reference
Doserate and the dose required