Association of lung and heart dose with survival in patients with non-small cell lung cancer underwent volumetric modulated arc therapy

Figures & data

Table 1 Characteristics of patients with lung cancer who underwent VMAT treatment

Characteristics	All patients (N=130)
Median age, y (range)	63 (34–82)
Sex
Male	100 (76.9%)
Female	30 (23.1%)
Pathology
Adenocarcinoma	48 (36.9%)
Squamous cell	64 (49.3%)
Mixed	16 (12.3%)
Others	2 (1.5%)
Stage
IIIA	58 (44.6%)
IIIB	72 (55.4%)
Chemotherapy
With	87 (66.9%)
Without	43 (33.1%)
Radiation pnuemonitis
Grade 0	16 (12.3%)
Grade I	70 (53.8%)
Grade II	33 (25.4%)
Grade III	10 (7.7%)
Grade IV	1 (0.8%)
Fibrosis
Grade 0	6 (4.6%)
Grade I	69 (53.1%)
Grade II	44 (33.8%)
Grade III	11 (8.5%)

Abbreviation: VMAT, volumetric modulated arc therapy.

Table 2 Dosimetric parameters of patients with lung cancer who underwent VMAT treatment

Median radiation dose, Gy (range)	56 (40–70)
PTV, mean±SD
Dmax (Gy)	60.6±8.8
Dmean (Gy)	55.7±0.8
V93 (%)	90.7±12.2
V95 (%)	87.4±14.0
HI	0.02±0.01
Cord, mean±SD
Dmax (Gy)	32.3±10.5
D2 (Gy)	31.6±10.7
Heart, mean±SD
Dmean (Gy)	14.8±8.5
V5 (%)	54.1±29.9
V15 (%)	37.4±24.7
V25 (%)	25.1±17.3
V30 (%)	20.1±14.0
V50 (%)	6.4±6.5
Lung, mean±SD
Dmean (Gy)	13.6±4.4
V5 (%)	59.1±19.2
V10 (%)	44.1±16.7
V13 (%)	36.4±13.7
V20 (%)	23.9±7.9
V30 (%)	15.2±5.1

Abbreviations: VMAT, volumetric modulated arc therapy; PTV, planning target volume; HI, homogeneity index.

Figure 1 Heatmap of Pearson correlation between heart and lung dosimetric parameters.

Abbreviations: GTV, gross tumor volume; PTV, planning target volume; RP, radiation pneumonitis; HI, homogeneity index.

Table 3 Univariate and multivariate analysis of factors associated with overall survival and progression-free survival with Cox model

	OS						PFS
Characteristics	Univariate analysis			Multivariate analysis			Univariate analysis
	HR	95% CI	p	HR	95% CI	p	HR	95% CI	p
Age	1.02	0.987–1.043	0.29				0.99	0.966–1.013	0.36
Sex	1.53	0.780–2.991	0.22				1.25	0.688–2.253	0.47
Pathology	1.19	0.871–1.621	0.28				0.92	0.705–1.199	0.36
Chemotherapy	1.26	0.658–2.415	0.49				1.19	0.690–2.064	0.53
Radiation pnuemonitis	1.54	1.004–2.364	0.048	1.39	1.010–1.909	0.043	1.14	0.794–1.639	0.48
Fibrosis	1.12	0.728–1.734	0.60				1.25	0.840–1.857	0.27
Prescription dose	1.00	0.999–1.001	0.93				1.00	0.999–1.003	0.65
PTV
Dmax	1.00	0.998–1.003	0.99				1.00	0.999–1.003	0.25
Dmean	1.00	0.997–1.002	0.81				0.99	0.997–1.001	0.19
V93	0.91	0.747–1.110	0.35				0.97	0.841–1.109	0.62
V95	1.12	0.952–1.308	0.18				1.06	0.948–1.191	0.30
Cord
Dmax	1.00	0.993–1.007	0.99				1.00	0.995–1.008	0.65
D2	1.00	0.993–1.007	0.95				1.00	0.992–1.005	0.60
Heart
Dmean	1.00	0.998–1.002	0.97				1.00	0.999–1.003	0.32
V5	0.99	0.959–1.022	0.52				0.98	0.956–1.013	0.28
V15	1.04	0.985–1.093	0.17	1.02	1.006–1.025	0.002	1.03	0.980–1.082	0.25
V25	1.03	0.934–1.135	0.56				0.91	0.745–1.106	0.28
V30	0.93	0.845–1.012	0.089				1.07	0.907–1.262	0.42
V50	1.09	0.989–1.194	0.083				0.95	0.895–1.084	0.76
Lung
V5	1.03	0.960–1.094	0.47				0.99	0.923–1.054	0.68
V10	0.86	0.706–1.035	0.11				0.99	0.775–1.167	0.63
V13	1.12	0.879–1.429	0.36				0.95	0.753–1.236	0.78
V20	1.04	0.845–1.288	0.69				1.22	1.013–1.470	0.04
V30	0.98	0.829–1.167	0.85				0.89	0.757–1.050	0.17
Dmean	1.00	0.999–1.003	0.23				1.00	0.998–1.004	0.41

Abbreviations: PTV, planning target volume; OS, overall survival; PFS, progressive-free survival.

Figure 2 Progression-free survival (PFS) and overall survival (OS) with 95% confidence interval of patients with non-small cell lung cancer who underwent volumetric modulated arc therapy.

Figure 3 The Kaplan–Meier curve and p-value (0.001) from stratified Cox proportional hazards model.