Organ at risk	Dose constraint	Maximum limit
		50 Gy/5F	48 Gy/4F
Bronchus and trachea	Max (Gy)	<52.5	<50.4
	V15.6 Gy (mL)	–	<4
	V18 Gy (mL)	<4	–
	V32 Gy (mL)	–	<1
Lungs‐GTV	Mean (Gy)	<4	<4
	V20 Gy (mL)	<8%	<8%
Heart	Max (Gy)	<52.5	<50.4
	V27 Gy (mL)	–	<1
	V32 Gy (mL)	<15	–
Brachial plexus	Max (Gy)	<32	<32
	V23.6 Gy (mL)	–	<3
	V30 Gy (mL)	<3	–
Oesophagus	Max (Gy)	<52.5	<50.5
	V18.8 Gy (mL)	–	<5
	V27.5 Gy (mL)	<5	<1
Chest wall	V30 Gy (mL)	<30	<30
Spinal cord	Max (Gy)	<28	<28
	V13.5 Gy (mL)	< 0.5	<1.2
	V20.8 Gy (mL)	–	<0.35
	V22.5 Gy (mL)	<0.25	–
Vertebrate	Max (Gy)	<54	<54
Great vessels	Max (Gy)	<52.5	<45
	V39 Gy (mL)	–	<10
	V47 Gy (mL)	<10	–
Skin	Max (Gy)	<32	<32
	V24 Gy (mL)	<10	<10
Ribs	Max (Gy)	<52.5	<50.4

D_{n cc} dose received by a volume of n cc; GTV, gross tumour volume; Max, maximum dose; V _50%, volume receiving 50% of prescription dose; V_{n Gy}, volume receiving a dose of n Gy.