Table 2 Critical organ constraints

Liver metastases

Normal liver

V21 < 33%

V15 < 50%

stomach

V21 < 5 cm³

Spinal cord

maximal dose < 22 Gy

Kidney

V 15 < 33%

Lung metastases

normal lung (= volume of right + left lung – PTV)

V5 < 50%

V10 < 30%

One lung

V 20 < 20%

Heart

V24 < 15 cm³

Dmax < 30 Gy

trachea and principal bronchi

V 15 < 4 cm³

V 20 < 1 cm³

Dmax < 30 Gy

esophagus

V 21 < 5 cm³

Dmax < 25 Gy