Table 1.

Clinical objectives for the three cases used to assess consistency of inverse planning

Plan	Structure	Objective	Importance factor
esophagus	PTV	uniform dose 55 Gy	100
	spinal cord	maximum dose 45 Gy	10
	left lung	$V_{18}$ a less than 10%	1
	right lung	$V_{18}$ less than 10%	1
prostate	PTV	uniform dose 74 Gy	20
	rectum	$V_{60}<20\%$	10
		$V_{40}<30\%$	5
	bladder	$V_{60}<20\%$	1
	left femoral head	$V_{52}<10\%$	2
	right femoral head	$V_{52}<10\%$	2
thyroid	PTV	uniform dose 60 Gy	0.1
	spinal cord	maximum dose 45 Gy	100

^aThis notation denotes volume of structure irradiated to 18 Gy and so on.