618-619 / 2001
Planning Target Volume
PTV
Th PTV
d th CTV ith
i t
t f th diff
t
e
surroun s e
w
a marg n o compensa e or e
eren
types of variations and uncertainties of treatment delivery
to the CTV.
The PTV is a geometrical concept, introduced for treatment planning.
A margin must be added to the CTV
•
to compensate for expected physiological movements and variations in size,
h d i i
f h C d i
h (i
l
i )
s ape an pos t on o t e TV ur ng t erapy nterna marg n
•
for uncertainties (inaccuracies and lack of reproducibility) in patient
irradiation.