Table I.

Treatment and dose-volume parameters, monitor units, gantry period, and beam-on times of the four helical tomotherapy plans for patients with stage I lung cancer.

	Mean ± standard deviation
	2.5-cm Dynamic	2.5-cm Fixed	p*	5.0-cm Dynamic	5.0-cm Fixed	p**	p***
Patient number			10
Total PTV (ml)			22.7 ± 10.3
Pitch			0.215, 0.287
Modulation factor			2.0
Conformity index	1.28 ± 0.12	1.30 ± 0.06	0.32‡	1.29 ± 0.05	0.16‡	0.39†
Uniformity index	1.09 ± 0.02	1.10 ± 0.02	0.02||	1.10 ± 0.02	1.11 ± 0.03	0.05||	0.0002§
Monitor unit	5525 ± 644	5066 ± 635	0.002‡	3988 ± 245	3219 ± 363	0.002‡	<0.0001†
Gantry period (sec)	38.1 ± 5.8	35.2 ± 5.1	<0.0001||	41 ± 8.3	32.1 ± 3.9	0.002||	<0.0001§
Beam-on time (sec)	397.9 ± 45.1	365.9 ± 44.6	0.002‡	290.3 ± 17.4	236.2 ± 25.4	0.002‡	<0.0001†
Body
V5 Gy (ml)	1825.6 ± 409.4	2143.4 ± 441.6	<0.0001||	1983.4 ± 401.6	2938.9 ± 559.9	<0.0001||	<0.0001§
V10 Gy (ml)	806.1 ± 255.2	909.0 ± 271.8	<0.0001||	881.5 ± 264.7	1196.4 ± 335.7	<0.0001||	<0.0001§
V20 Gy (ml)	240.3 ± 89.5	269.5 ± 91.3	<0.0001||	265.6 ± 96.3	354.0 ± 113.2	<0.0001||	< 0.0001§
V30 Gy (ml)	115.4 ± 43.3	128.0 ± 43.4	<0.0001||	127.9 ± 46.4	163.4 ± 51.9	<0.0001||	< 0.0001§
Spinal cord maximum (Gy)	10.3 ± 4.6	10.9 ± 4.8	0.003||	9.2 ± 4.6	8.9 ± 4.9	0.80||	0.02§
Esophagus maximum (Gy)	14.1 ± 4.1	14.3 ± 4.2	0.14||	14.0 ± 3.8	14.1 ± 4.1	0.68||	0.31§

Abbreviation: PTV: Planning target volume.

^*p-value between 2.5-cm dynamic- and 2.5-cm fixed- jaw plans.

^**p-value between 5.0-cm dynamic- and 5.0-cm fixed- jaw plans.

^***p-value among the four plans.

^†Calculated by Friedman analysis of variance.

^‡Calculated by Wilcoxon signed-rank test.

^§Calculated by parametric analysis of variance for depended samples.

^||Calculated by paired t-test.