Simultaneous modulated accelerated radiation therapy for esophageal cancer: A feasibility study

Table 1 Patient and tumor characteristics

No.	Site	Stage1	V-GTV (cc)	V-LN (cc)	V-PTV66 (cc)	V-PTV60/54 (cc)
1	Upper	T2N1M1b	11.5	11	80	206.3
2	Middle	T3N0M0	18.1	0	49.1	151.2
3	Upper	T3N1M1a	38.8	3	102.1	253.3
4	Upper	T3N1M0	25.4	1.3	75	191.6
5	Upper	T3N2M0	16.9	1	47.8	196.4
6	Middle	T3N1M0	24.6	6	86.8	197.6
7	Middle	T4N1M1b	32.1	2.7	82.5	214.4
8	Middle	T3N0Mo	15.8	0	42.5	149.9
9	Middle	T3N0Mo	14.9	0	41	144.6
10	Upper	T3N0Mo	16.1	0	45.5	161.9

¹According to the 2002 American Joint Committee on Cancer staging system. V-GTV: Volume of gross target tumor; V-LN: Volume of lymph node; V-PTV: Volume of planning target volume.

Table 2 Averaged over ten patients dose-volume histograms parameters of organs at risk with P-value for comparison

		SMART	IMRT	3DCRT	P value
					SMART vs IMRT	SMART vs 3DCRT
Cord	Dmax	38.5 ± 2.0	39.5 ± 0.9	44.7 ± 0.8	0.660	0.0021
	D1cc	35.6 ± 2.2	36.3 ± 1.2	41.6 ± 1.6	0.266	0.000
SC-PRV	Dmax	44.5 ± 1.9	47.1 ± 2.7	59.3 ± 2.2	0.0101	0.0021
	D1cc	40.8 ± 2.5	42.5 ± 2.2	52.9 ± 3.8	0.0271	0.0021
Heart	Dmean	14.4 ± 7.5	16.2 ± 8.5	21.4 ± 11.1	0.000	0.000
	V20	34.1 ± 18.9	38.1 ± 21.9	42.7 ± 22.4	0.005	0.000
	V30	18.2 ± 10.0	21.8 ± 11.6	38.0 ± 21.0	0.001	0.001
	V40	9.4 ± 5.7	12.2 ± 7.2	25.3 ± 16.3	0.001	0.0021
	V50	4.9 ± 3.4	7.0 ± 4.6	12.9 ± 7.6	0.001	0.000
Lung	Dmean	9.0 ± 1.7	9.9 ± 1.8	12.4 ± 2.1	0.000	0.000
	V5	47.6 ± 9.7	50.4 ± 10.2	51.0 ± 9.9	0.000	0.017
	V10	34.7 ± 7.4	37.6 ± 7.6	40.6 ± 8.1	0.000	0.002
	V13	27.3 ± 5.9	30.2 ± 6.1	34.7 ± 7.3	0.000	0.000
	V20	17.1 ± 4.0	20.2 ± 4.3	25.8 ± 5.0	0.000	0.000
	V30	3.6 ± 1.3	4.7 ± 1.6	13.4 ± 4.8	0.000	0.000

¹By Wilcoxon matched-pair signed-rank test using exact method. SMART: Simultaneous modulated accelerated radiation therapy; IMRT: Intensity-modulated radiation therapy; 3DCRT: Three-dimensional conformal radiotherapy; SC-PRV: Spinal cord planning risk volume.