Re-irradiating spinal column metastases using IMRT and VMAT with and without flattening filter - a treatment planning study

Table 1 Dose Volume Objectives (DVO)

Organ	Type	DVO	relative weight
PTV	target	uniform dose 24.0 Gy	7000
		minimum dose 23.5 Gy	7000
		maximum dose 24.5 Gy	7000
spinal canal	organ at risk	maximum dose 18.0 Gy	750
spinal cord	organ at risk	maximum dose 16.0 Gy	1000
normal tissue	organ at risk	maximum dose 24.5 Gy	5000
normal tissue	organ at risk	surrounding dose fall off from 24.0 to 4.8 Gy in 5.0 cm	5000

Identical dose volume objectives (DVO) and weights were used for optimization of all plans

ISSN: 1748-717X