Geometric and dosimetric consequences of intra-fractional movement in single isocenter non-coplanar stereotactic radiosurgery

Table 4 Change in V_12Gy the normal brain (brain-GTV) due to intra-fractional movement or addition of PTV margin

ΔV_12Gy (cc)	Intra-fractional movement			Addition of PTV margin (compared to the plan without margin)
ΔV_12Gy (cc)	Mean	Max	p	Mean	Max	p
0 mm margin	0.0	0.1	0.09	NA	NA	< 0.001
1 mm margin	0.0	0.2	0.04	1.2	5.8	< 0.001
2 mm margin	0.0	0.1	0.10	2.4	12.7	< 0.001

ISSN: 1748-717X