Comparison of conformal and intensity-modulated techniques for simultaneous integrated boost radiotherapy of upper esophageal carcinoma

Table 1 Beam arrangement of IMRT plans

Number of beams	Gantry angles
3	0o, 120o, 240o
5	0o, 72 o, 144 o, 216o, 288o
7	0o, 52 o, 103 o, 154 o, 206 o, 257o, 308o
9	0o, 40 o, 80 o, 120 o, 160 o, 200 o, 240 o, 280o, 320o

Table 2 Results for CRT and IMRT in five upper esophageal cancer patients(mean±SD)

Stucture	Parameter	CRT	3F IMRT	5F IMRT	7F IMRT	9F IMRT
PTV1	Mean dose (Gy)	73.0 ± 3.0	74.9 ± 3.8	74.2 ± 2.3	73.9 ± 2.0	74.1 ± 1.5
	SD (%)	6.3 ± 3.7	6.7 ± 2.7	6.0 ± 2.0	5.7 ± 2.1	6.0 ± 1.7
	D95 (Gy)	67.2 ± 0.0	67.2 ± 0.0	67.2 ± 0.0	67.2 ± 0.0	67.2 ± 0.0
	CI	0.47 ± 0.16	0.59 ± 0.18	0.70 ± 0.04	0.74 ± 0.06	0.75 ± 0.07
PTV2	Mean dose (Gy)	65.3 ± 4.4	60.0 ± 2.3	59.3 ± 1.4	58.4 ± 1.8	58.4 ± 2.0
	SD (%)	11.6 ± 3.8	9.2 ± 1.8	8.8 ± 1.5	8.5 ± 1.9	8.6 ± 1.8
	D95 (Gy)	52.4 ± 3.3	51.2 ± 2.8	50.8 ± 3.4	50.5 ± 3.3	51.2 ± 2.9
	CI	0.52 ± 0.08	0.46 ± 0.11	0.64 ± 0.06	0.67 ± 0.07	0.68 ± 0.08
Lung	Mean dose (Gy)	12.4 ± 1.7	11.1 ± 1.2	10.8 ± 1.3	10.7 ± 1.3	10.9 ± 1.2
	V20 (%)	24.7 ± 2.8	22.1 ± 1.7	22.4 ± 0.7	23.2 ± 1.6	23.8 ± 1.7
	V30 (%)	18.6 ± 2.9	15.1 ± 1.6	15.0 ± 1.9	13.5 ± 2.2	13.5 ± 3.2
Spinal cord	Maximum dose (Gy)	40.9 ± 2.7	56.9 ± 7.2	43.9 ± 1.0	43.3 ± 0.8	42.0 ± 1.5