Target Volume Determination 2015

CTV → PTV (Planning Target Volume) OAR → PRV (Planning Organs at Risk Volume)

5 mm

The recommended CTV margin to create PTV is at least 5 mm. But, PTV outside skin can ’ t be used for dosimetric calculations (air, outside the body ...). Typical solutions: 1. To crop PTV by 3 mm (without reaching the skin) but treatment planning carried out with 2-3 cm 2. To create PTV outside the body (margin for breathing) without croping → An additional “ cropped ” PTV volume will then be needed for normalization purposes and DVH analysis