Table 1.

This table demonstrates the normal tissue constraints used in the radiation therapy planning process

Structure	Metric	Per protocol	Source
Bony spinal canal	Max dose 0.03cc	≤50 Gy	13
Oesophagus	Max dose 0.03cc	<63 Gy	13
	Mean	<34 Gy	13
Heart	V40	<30%
	V50	<25%	33
	Mean	<20 Gy	5
	Max dose 0.03cc	<70 Gy	13
Brachial plexus	Max dose 0.03cc	<63 Gy	13
Proximal bronchial tree	Max dose 1.0cc	<64.5 Gy	3
Great vessels (normal)	Max dose 0.03cc	<80 Gy	34
Great vessels (tumour involved)	Max dose 0.03cc	<70 Gy	34
Lung dose constraints
Structure	Metric	Per protocol	Definition	Source
Lungs (anatomic)	Mean	<20 Gy	Mean dose to the whole anatomic lung	13
Left+right lung-IGTV	V30	<30%	Volume of structure (%) receiving ≥30 Gy	13 35
	V20	<35%	Volume of structure (%) receiving ≥20 Gy	13 35
	V5	<66%	Volume of structure receiving ≥5 Gy	13 35