Monitoring of mechanical errors and their dosimetric impact throughout the course of non-coplanar continuous volumetric-modulated arc therapy

Table 3 Summary of dosimetric errors in the CTV and OARs for skull base tumor throughout the course of VMDWAT. Values are shown in means ± two standard deviations for the signed difference and those for the absolute difference in parentheses

Patient	CTV			Chiasm		Right optic nerve		Left optic nerve
Patient	D_99% (%)	D_mean (%)	D_1% (%)	D_2% (%)	D_mean (%)	D_2% (%)	D_mean (%)	D_2% (%)	D_mean (%)
1	0.2 ± 0.5 [0.2 ± 0.4]	0.3 ± 0.6 [0.3 ± 0.6]	0.3 ± 0.6 [0.3 ± 0.6]	0.2 ± 0.2 [0.2 ± 0.2]	0.4 ± 0.4 [0.4 ± 0.4]	0.4 ± 0.2 [0.4 ± 0.3]	−0.1 ± 0.5 [0.2 ± 0.4]	0.1 ± 1.3 [0.5 ± 1.0]	1.4 ± 1.1 [1.4 ± 1.1]
2	0.1 ± 0.4 [0.1 ± 0.4]	0.0 ± 0.5 [0.2 ± 0.3]	0.1 ± 0.7 [0.3 ± 0.5]	0.1 ± 0.6 [0.2 ± 0.5]	0.1 ± 0.5 [0.2 ± 0.4]	0.2 ± 0.4 [0.2 ± 0.4]	−0.4 ± 0.3 [0.4 ± 0.3]	0.1 ± 0.4 [0.2 ± 0.3]	0.0 ± 0.3 [0.1 ± 0.2]

Abbreviations: CTV clinical target volume, OARs organs at risk, VMDWAT volumetric-modulated Dynamic WaveArc therapy, D_mean mean dose, D_xx% dose covering xx% volume

ISSN: 1748-717X