A treatment planning study comparing IMRT techniques and cyber knife for stereotactic body radiotherapy of low-risk prostate carcinoma

Radiation Oncology

Table 3 Summary of dosimetric indices averaged from the treatments plans of 27 patients

Index	HT Mean ± SD	SW Mean ± SD	VMAT Mean ± SD	CK Mean ± SD
Homogeneity index, HI	0.18 ± 0.01*	0.21 ± 0.01	0.19 ± 0.01	0.21 ± 0.04*
Conformation number, CN	0.85 ± 0.05	0.81 ± 0.05	0.87 ± 0.03	0.87 ± 0.06
ICRU Conformity index, CIICRU	1.16 ± 0.08	1.22 ± 0.07	1.13 ± 0.04	1.08 ± 0.07
Coverage index, CΔ	0.16 ± 0.08	0.23 ± 0.07	0.14 ± 0.04	0.11 ± 0.06
Coverage index, COV	0.99 ± 0.01	0.99 ± 0.01	0.99 ± 0.01	0.97 ± 0.02

Abbreviations: VMAT Volumetric Modulated Arc Therapy, SW Sliding Window, HT Helical tomotherapy, CK Cyber Knife, SD Standard deviation, HI Homogeneity index, CN Conformation number, CIICRU ICRU conformity index, C∆ Coverage index, COV Coverage index COV; *-values with statistically significant difference (p < 0.05)