Background
Methods
Patients
Treatment plans
Non-coplanar dynamic arcs (DA)
Coplanar VMAT Rapidarc® (RA)
Quality control
Analyses
Results
Target coverage (Fig. 1a)
Indices | Dynamic arc (DA) | Rapidarc (RA) |
p-value |
---|---|---|---|
D50 % (Gy) (%) | 52.5 ± 1.2 | 52.6 ± 0.7 | DA vs RA p = 0.54 |
100.0 ± 1.7 | 100.2 ± 0.2 | ||
D95 % (Gy) (%) | 50.0 ± 1.2 | 51.3 ± 0.8 | DA vs RA
p = 0.006 |
95.2 ± 1.6 | 97.7 ± 0.9 | ||
D2 % (Gy) (%) | 54.3 ± 1.0 | 53.6 ± 0.8 | DA vs RA
p = 0.01 |
103.5 ± 1.5 | 102.1 ± 0.6 | ||
D mean (Gy) (%) | 52.2 ± 0.9 | 52.3 ± 0.7 | DA vs RA p = 0.17 |
99.4 ± 1.2 | 99.5 ± 1.1 | ||
D98 % (Gy) (%) | 49.8 ± 1.9 | 50.5 ± 0.8 | DA vs RA p = 0.25 |
94.9 ± 2.9 | 96.2 ± 1.6 | ||
V95 % (%) | 95.9 ± 5.5 | 98.8 ± 1.0 | DA vs RA p = 0.09 |
V107 % (%) | 0.15 ± 0.5 | 0.01 ± 0 | DA vs RA p = 0.36 |
CI (%) | 67.9 ± 8.3 | 75.2 ± 10.4 | DA vs RA
p = 0.04 |
HI | 0.09 ± 0 | 0.06 ± 0 | DA vs RA
p = 0.01 |
Organs at risk (Fig. 1b and c)
Organs | Dynamic arc (DA) | Rapidarc (RA) |
p-value | |
---|---|---|---|---|
Brainstem | D2 % (Gy) | 47.4 ± 13.6 | 47.1 ± 12.0 | DA vs RA p = 0.81 |
Spinal cord | D2 % (Gy) | 8.9 ± 5.2 | 1.8 ± 1.9 | DA vs RA
p = 10–4 |
Pituitary glanda
| D2 % (Gy) | 23.7 ± 19 | 28.6 ± 16.5 |
DA vs RA p = 0.01 |
D mean (Gy) | 17.3 ± 16 | 22.2 ± 15.4 |
DA vs RA p = 0.02 | |
Chiasm | D2 % (Gy) | 32.7 ± 22.5 | 29.3 ± 23.4 | DA vs RA
p = 0.01 |
Hippocampus | D mean (Gy) | 16.7 ± 9.2 | 11.9 ± 5.5 | DA vs RA
p = 0.006 |
D40 % (Gy) | 16.2 ± 10.5 | 9.9 ± 5.7 | DA vs RA p = 0.005 | |
Ipsilateral cochlea | D2 % (Gy) | 39.4 ± 18.0 | 33.8 ± 13.8 | DA vs RA
p = 0.008 |
D mean (Gy) | 35.3 ± 18.0 | 25.4 ± 9.7 | DA vs RA
p = 0.008 | |
Controlateral cochlea | D2 % (Gy) | 12.5 ± 12.3 | 17.9 ± 8.4 |
DA vs RA p = 0.05 |
D mean (Gy) | 10.8 ± 11.1 | 15.8 ± 7.9 |
DA vs RA p = 0.04 | |
Cerebellum | D mean (Gy) | 8.7 ± 7.0 | 10.7 ± 5.6 | DA vs RA p = 0.11 |
Ipsilateral lens | D2 % (Gy) | 1.1 ± 1.5 | 3.1 ± 2.2 |
DA vs RA p = 0.01 |
D mean (Gy) | 0.9 ± 1.3 | 2.4 ± 1.9 |
DA vs RA p = 0.01 | |
Controlateral lens | D2 % (Gy) | 1.4 ± 1.9 | 3.2 ± 2.1 |
DA vs RA p = 0.01 |
D mean (Gy) | 1.1 ± 1.5 | 2.5 ± 1.9 |
DA vs RA p = 0.01 | |
Ipsilateral optic nerve | D2 % (Gy) | 26.8 ± 23.1 | 26.3 ± 22.5 | DA vs RA p = 0.83 |
Controlateral optic nerve | D2 % (Gy) | 21.7 ± 19.9 | 24.0 ± 20.6 | DA vs RA p = 0.62 |
Ipsilateral eyeball | D2 % (Gy) | 4.1 ± 2.9 | 9.2 ± 4.5 |
DA vs RA p = 10–4 |
D mean (Gy) | 0.6 ± 0.9 | 1.4 ± 1.3 | DA vs RA p = 0.09 | |
Controlateral eyeball | D2 % (Gy) | 3.3 ± 3 | 10.2 ± 4.9 |
DA vs RA p = 10–4 |
D mean (Gy) | 0.2 ± 0.3 | 1.5 ± 1.4 |
DA vs RA p = 0.002 | |
Healthy brain (i-e brain-PTV) | D mean (Gy) | 6.7 ± 2.7 | 5.1 ± 1.8 | DA vs RA
p = 0.002 |
V100 % (%) | 0.4 ± 0.8 | 0.02 ± 0 | DA vs RA
p = 0.02 | |
V95 % (%) | 0.9 ± 1.2 | 0.3 ± 0.2 | DA vs RA
p = 0.03 | |
V90 % (%) | 1.4 ± 1.4 | 0.7 ± 0.4 | DA vs RA
p =0.05 | |
V80 % (%) | 2.2 ± 2.1 | 1.3 ± 0.7 | DA vs RA p =0.06 |
Low-dose irradiation (Fig. 1d)
Indices | Dynamic arc (DA) | Rapidarc (RA) |
p-value |
---|---|---|---|
Dmean (Gy) | 3.9 ± 1.9 | 3.7 ± 1.7 | DA vs RA p = 0.41 |
V30 Gy (cm3) | 100.5 ± 99.7 | 92.6 ± 72.9 | DA vs RA p = 0.49 |
V20 Gy (cm3) | 166.1 ± 158.8 | 184.4 ± 127.0 | DA vs RA p = 0.14 |
V10 Gy (cm3) | 425.1 ± 328.8 | 476.4 ± 226.4 | DA vs RA p = 0.09 |
V5 Gy (cm3) | 1056.0 ± 569.7 | 1264.9 ± 1551.6 | DA vs RA p = 0.17 |