A comparative study of target volumes based on ¹⁸F-FDG PET-CT and ten phases of 4DCT for primary thoracic squamous esophageal cancer

Figures & data

Table 1 The characteristics of the patients enrolled in the study

Patients	Sex	Age (years)	Tumor location	SUVmax	Pathologic type	TNM stage
1	Female	77	Middle	19.39	Squamous	T2N1Mx
2	Male	69	Distal	9.33	Squamous	T3N2M0
3	Female	57	Middle	9.71	Squamous	T2N1M0
4	Male	74	Middle	12.29	Squamous	T3N1M0
5	Female	66	Distal	11.82	Squamous	T1N1M0
6	Female	74	Middle	10.41	Squamous	T2N1M0
7	Male	53	Upper	17.39	Squamous	T2N0M0
8	Male	71	Distal	30.46	Squamous	T3N2Mx
9	Male	62	Distal	17.2	Squamous	T2N2M0
10	Female	58	Middle	14.55	Squamous	T2N1M0
11	Male	80	Middle	15.98	Squamous	T2N0Mx
12	Male	68	Distal	15.32	Squamous	T3N2M0
13	Male	44	Distal	9.13	Squamous	T3N1M0
14	Male	58	Upper	13.67	Squamous	T2N1M0
15	Male	63	Middle	7.40	Squamous	T3N0M0
16	Female	52	Upper	19.85	Squamous	T4N1M0
17	Male	71	Distal	15.57	Squamous	T2N1Mx
18	Male	57	Middle	11.96	Squamous	T3N2Mx
19	Male	44	Upper	9.36	Squamous	T3N2M0
20	Male	65	Upper	11.87	Squamous	T2N1M0

Note: “x” = distant metastasis unknown.

Abbreviation: SUV, standardized uptake value.

Table 2 The variation of intraobserver for the comparison of the GTV volume between different times (cm³)

Time	Upper		Middle		Lower		Overall
First	19.22	12.32	20.28	69.44	38.07	24.11	30.57±8.52
Second	23.51	9.93	24.35	71.07	39.77	28.33	32.83±8.59
P-value	–	–	–	–	–	–	P=0.086

Abbreviation: GTV, gross target volume.

Figure 1 An example of the contours delineated in the image sessions in transversal (A), sagittal (B), and coronal section (C).

Note: The pink contour represents the GTV on SUV_20%, and the green one represents IGTV₁₀.
Abbreviations: GTV, gross target volume; SUV, standardized uptake value.

Table 3 The target centroid shift between GTV_PET and IGTV₁₀ in LR, AP, and CC directions, and 3D represents the centroid distance between GTV_PET and IGTV₁₀ (mean ± SD, and median, mm)

Target terms	LR	AP	CC	Centroid distance
SUV2.0	−0.39±1.99 (−0.15)	0.37±1.70 (0.45)	3.33±6.26 (1.45)	5.73±4.83 (4.06)
SUV2.5	−0.65±1.99 (−0.53)	0.73±1.86 (0.50)	3.24±6.71 (2.15)	6.55±4.40 (5.63)
SUV3.0	−0.63±2.20 (−0.46)	0.74±1.99 (0.40)	2.48±6.13 (1.95)	5.78±4.32 (4.43)
SUV3.5	−0.58±2.26 (−0.66)	0.65±1.99 (0.45)	2.61±6.75 (1.70)	6.00±4.93 (4.10)
SUV20%	−0.28±2.02 (0.05)	0.45±1.50 (0.50)	2.63±6.69 (1.70)	5.87±4.73 (4.02)
SUV25%	−0.59±2.25 (−0.45)	0.69±1.90 (0.45)	3.44±6.84 (2.25)	6.54±7.74 (2.50)
SUV30%	−0.81±2.36 (−1.23)	0.64±1.95 (0.35)	2.75±6.53 (2.35)	6.22±4.53 (5.10)
SUV35%	−0.78±2.31 (−1.30)	0.58±2.08 (0.40)	2.41±6.53 (1.95)	6.07±4.53 (4.85)
SUV40%	−0.88±2.37 (1.35)	0.56±2.25 (0.50)	2.12±6.20 (1.75)	5.91±4.26 (4.92)
Manual contouring	−0.77±1.85 (−0.70)	0.70±2.38 (0.62)	2.66±5.60 (1.83)	5.21±4.57 (4.53)

Abbreviations: GTV, gross target volume; LR, left–right; AP, anterior–posterior; CC, cranial–caudal; SUV, standardized uptake value.

Table 4 The VR, DI, and CI of GTV_PET and IGTV₁₀ (mean ± SD and median)

Parameters	VR	DIs of GTVPET and IGTV10		CI
		IGTV10in GTVPET	GTVPET in IGTV10
SUV2.0	1.35±0.42 (1.30)	0.78±0.14 (0.83)	0.60±0.13 (0.16)	0.51±0.11 (0.50)
SUV2.5	0.95±0.32 (0.93)	0.67±0.17 (0.72)	0.73±0.11 (0.74)	0.53±0.13 (0.54)
SUV3.0	0.74±0.29 (0.74)	0.58±0.20 (0.65)	0.81±0.10 (0.84)	0.50±0.15 (0.53)
SUV3.5	0.62±0.28 (0.65)	0.52±0.21 (0.59)	0.86±0.09 (0.88)	0.46±0.17 (0.51)
SUV20%	1.06±0.50 (0.86)	0.69±0.12 (0.68)	0.72±0.18 (0.77)	0.53±0.12 (0.55)
SUV25%	0.74±0.26 (0.68)	0.58±0.13 (0.61)	0.81±0.13 (0.85)	0.51±0.12 (0.51)
SUV30%	0.56±0.17 (0.57)	0.49±0.12 (0.50)	0.87±0.10 (0.90)	0.45±0.11 (0.46)
SUV35%	0.45±0.13 (0.46)	0.41±0.12 (0.42)	0.90±0.08 (0.92)	0.39±0.11 (0.40)
SUV40%	0.37±0.13 (0.37)	0.35±0.12 (0.34)	0.79±0.26 (0.93)	0.33±0.11 (0.33)
Manual contouring	1.07±0.49 (1.13)	0.74±0.20 (0.82)	0.75±0.26 (0.74)	0.54±0.14 (0.58)

Abbreviations: GTV, gross target volume; SUV, standardized uptake value; VR, volume ratio; CI, conformity index; DI, degree of inclusion; SD, standard deviation.

Table 5 The best VR and CI for low SUV_max, median SUV_max, and high SUV_max groups

Parameters	Low SUVmax	Median SUVmax	High SUVmax
The best SUV value for VR and CI	2, 25% SUVmax, manual contouring	2.5, 20% SUVmax, manual contouring	3.0, 3.5, manual contouring

Abbreviation: SUV, standardized uptake value.

Table 6 The best VR and CI for upper, middle, and distal segment groups

Parameters	Upper	Middle	Distal
The best SUV value for VR and CI	2.5, 20% SUVmax, manual contours	2.5, 20% SUVmax, manual contours	2.0, 20% SUVmax, manual contours

Abbreviations: SUV, standardized uptake value; VR, volume ratio; CI, conformity index.