Quantification of heart, pericardium, and left ventricular myocardium movements during the cardiac cycle for thoracic tumor radiotherapy

Figures & data

Table 1 Patient characteristics

Gender	Number	Median age	Tumor type
Male	12	58 (35–67)	Thoracic esophageal cancer
Female	10

Figure 1 Delineation of the heart, pericardium, and LVM.

Notes: (A) Delineation of the heart, pericardium, and LVM in transverse section. (B) Delineation of the heart, pericardium, and LVM in sagittal section. (C) Delineation of the heart, pericardium, and LVM in coronal section. Heart delineation is shown in yellow, pericardium delineation is shown in red, and LVM delineation is shown in blue.
Abbreviation: LVM, left ventricular myocardium.

Table 2 Displacements of the heart, pericardium, and LVM in reference to 0% phase CT images (mean ± standard deviation, mm)

	X	Y	Z
Heart	1.2±0.9	0.6±0.5	0.6±0.5
Pericardium	0.5±0.4	0.4±0.3	0.8±0.6
LVM	1.0±0.8	4.1±2.8	1.9±1.2

Abbreviations: LVM, left ventricular myocardium; CT, computed tomography.

Table 3 Volumetric and DSC variations of the heart, pericardium, and LVM

	Maximum	Minimum	Variation (%)	p-value
Volume, cm^3
Heart	574.24±117.26	493.15±99.65	16.49±3.85	<0.001
Pericardium	682.64±134.10	605.96±114.33	12.62±3.94	<0.001
LVM	82.36±19.19	66.31±14.67	24.23±11.35	<0.001
DSC
Heart	0.974±0.006	0.885±0.018	10.08±2.14	<0.001
Pericardium	0.982±0.005	0.934±0.015	5.20±1.54	<0.001
LVM	0.896±0.028	0.351±0.098	184.33±128.61	<0.001

Abbreviations: DSC, dice similarity coefficient; LVM, left ventricular myocardium.

Figure 2 Morphological variations of different phases of the heart, pericardium, and LVM.

Notes: (A) Delineation of the heart in different phases. (B) Morphological variations of different phases of the heart on CT (a significant difference was observed for the left boundary of the LVM). (C) Differences in the left boundary of the LVM are represented using pseudocolors, and significant differences are shown in red. (D) Delineation of the pericardium in different phases. (E) A case showing the LVM in the maximum DSC phase. (F) The same case showing the LVM in the minimum DSC phase. (G) The same case showing the LVM in the maximum and minimum DSC phases in one CT image; the variation of DSC was 700%. (H) Delineation of the LVM in different phases.
Abbreviations: LVM, left ventricular myocardium; CT, computed tomography; DSC, dice similarity coefficient.

Figure 3 Volumetric variation of the heart, pericardium, and LVM.

Note: The volumetric variation of the LVM was not consistent with those of the heart and pericardium; the volume of heart and pericardium decreased at first and later increased, and the volume of the LVM increased at first and later decreased.
Abbreviation: LVM, left ventricular myocardium.

Table 4 Comparison of the morphological parameters of the heart, pericardium, and LVM in the maximum and minimum DSC phases

	DSCmax	DSCmin	Variation (%)	p-value
Max 3D diameter
Heart	14.23±0.92	13.82±1.01	4.28±3.20	0.012
Pericardium	15.78±1.14	15.47±1.36	3.50±3.06	0.033
LVM	9.77±0.81	8.54±0.87	18.70±5.08	0.005
Roundness
Heart	0.41±0.05	0.39±0.06	7.41±6.05	0.003
Pericardium	0.43±0.05	0.42±0.05	5.38±3.95	0.073
LVM	0.10±0.03	0.12±0.02	15.36±9.22	0.001
Spherical disproportion
Heart	1.22±0.11	1.17±0.08	8.36±7.77	0.067
Pericardium	1.09±0.05	1.10±0.06	3.58±4.82	0.654
LVM	2.71±0.41	2.01±0.38	48.76±19.86	0.006
Sphericity
Heart	0.82±0.07	0.86±0.05	7.67±6.17	0.073
Pericardium	0.92±0.04	0.91±0.05	3.81±5.56	0.681
LVM	0.38±0.08	0.51±0.09	35.78±14.87	0.006
Surface area
Heart	397.38±70.75	352.82±56.02	17.41±10.06	0.006
Pericardium	397.99±65.85	380.78±59.56	9.28±7.84	0.117
LVM	220.37±37.82	175.06±44.85	38.72±20.90	0.010

Abbreviations: DSC, dice similarity coefficient; LVM, left ventricular myocardium.