Organs at risk (OAR) delineation and constraints

The organs at risk are: lung parenchyma, esophagus, spinal cord, heart and body. Dose constraints to organs at risk are respected to minimize the risk of complications. The constraints on the spinal cord, heart and the volume of the lung receiving at least 20 Gy are following (unless otherwise specified for patients included in other protocols)

Both lungs should be contoured in their entirety. The mean lung dose (MLD), the mean dose delivered to both lungs minus all GTV’s) will be calculated from dose-volume histogram (DVH) and should not exceed 20 Gy. The V_lung20 (the volume of lung outside the tumour receiving a dose of more than 20Gy) should not exceed 35%, aim for V5 < 60%;

The esophagus volume (outer muscular contour) must be contoured from the level of just below the larynx to the gastro-esophageal juncture. The PTV should not be subtracted from the total volume of the esophagus. Aim for dose to 1 cm³ under 100% of prescribed dose;

For spinal cord dose evaluation, it is mandatory to contour the spinal cord. The calculated near maximum dose to the spinal cord should not exceed 45 Gy or max 50 Gy for delineated spinal canal;

The heart dose should be kept as low as possible, following the constraints of V40 < 30% and V25 < 50%;

Body: global hotspot< 112%.