Helical tomotherapy and volumetric modulated arc therapy: New therapeutic arms in the breast cancer radiotherapy

Table 3 Doses to normal tissues

	VMAT	HT
Ipsilateral lung
V5	85.3% ± 9.6%	78.5% ± 12.6%
V20	20.1% ± 3.2%	21.1% ± 5%
V30	8.8% ± 3.2%	10.1 ± 3.3
Mean dose	13.6 ± 1.4 Gy	13.6 ± 1.2 Gy
Controlateral lung
V5	46% ± 14.1%	35.4 ± 11.3
V20	0.7% ± 0.5%	0.1 ± 0.2
Mean dose	5.4 ± 1 Gy	4.6 ± 0.8 Gy
Heart
Mean dose	10.3 ± 4.2 Gy	7.5 ± 1.4 Gy
V5	77.6% ± 21%	59.8 % ± 14.6%
V30	2.5% ± 3.9%	1% ± 1%
Controlateral breast
Mean dose	4.6 ± 0.9 Gy	3.6 ± 0.6 Gy
V5	32% ± 11.9%	14.7% ± 7%
Spinal cord
V40	0 mm3	0 mm3
V5	22.4 ± 8.8 mm3	25.2 ± 9 mm3
Oesophagus
V45	0.4 ± 0.6 mm3	1 ± 1.2 mm3
V10	8.8 ± 5.4 mm3	12.8 ± 5.7 mm3
Thyroid
Mean dose	28.3 ± 7 Gy	26.7 ± 7.7 Gy
V30	44% ± 15.3%	39.8% ± 17.6%
V5	97.1% ± 8.3%	96% ± 9.4%
Unspecified tissues
V40	1977 ± 911 mm3	1880.9 ± 754
V5	9770.3 ± 2551 mm3	8566.6 ± 1946.2

VMAT: Volumetric modulated arc therapy; HT: Helical tomotherapy.