Computed tomography 3D reconstruction and texture analysis for evaluating the efficacy of neoadjuvant chemotherapy in advanced gastric cancer

Table 1 Classification of postoperative pathological shrinkage of tumors

TRG grading	Content
TRG1a	(Complete remission): No residual tumor
TRG1b	(Subtle remission): Tumor residual < 10%
TRG2	(Partial relief): 10%< tumor residue < 50%
TRG3	(Minor or no relief): Tumor residual > 50%

TRG: Tumor regression grade.

Table 2 Comparison of general information between two groups of patients, n (%)

Project	Chemotherapy ineffective group (n = 35) (tumor residual ≥ 50%)	Chemotherapy effective group (n = 62) (tumor residual < 50%)	t/χ2	P value
Age	62.35 + 8.42	61.87 + 9.13	0.258	0.797
Gender			0.342	0.559
Male	24 (68.57)	39 (62.90)
Female	11 (31.43)	23 (37.10)
Staging			0.876	0.349
Stage II	13 (37.14)	29 (46.77)
Stage III	22 (62.86)	33 (53.23)
Location			0.523	0.470
Cardia	15 (42.86)	31 (50.00)
Gastric body	20 (57.14)	31 (50.00)
Lauren's classification			1.247	0.536
Diffuse type	14 (40.00)	21 (33.87)
Mixed type	8 (22.86)	19 (30.65)
Intestinal type	13 (37.14)	22 (35.48)

Table 3 Misjudgment rate of predicting the efficacy of neoadjuvant chemotherapy for gastric cancer using different texture feature selection and classification analysis methods in computed tomography images

Discrimination methods	RDA misclassification rate (%)	PCA misclassification rate (%)	LDA misclassification rate (%)	NDA misclassification rate (%)
Venous phase
Fisher	21.86	18.45	14.92	11.53
POE + ACC	19.75	16.82	13.45	9.86
MI	18.32	15.46	11.85	8.92
FPN	17.53	14.25	10.63	7.85
Arterial phase
Fisher	25.92	22.85	19.46	16.85
POE + ACC	24.53	21.46	18.25	15.42
MI	22.85	19.75	16.92	14.53
FPN	21.46	18.53	15.86	13.92

RDA: Raw data analysis; PCA: Principal component analysis; LDA: Linear discriminant analysis; NDA: Nonlinear discriminant analysis; POE+ACC: Probability of error plus average correlation coefficient; MI: Mutual information; FPN: False positive nodule.

Table 4 Comparison of volume and thickness change rates and correlation with postoperative pathological tumor regression grade

	Chemotherapy ineffective group (n = 35)	Chemotherapy effective group (n = 62)	Z	P1	r	P2
Tumor volume change rate (%)	41.75 (32.86, 48.52)	75.20 (65.42, 82.35)	7.246	< 0.001	0.886	< 0.001
Tumor thickness change rate (%)	29.83 (24.53, 35.62)	40.65 (35.28, 46.92)	5.835	< 0.001	0.725	< 0.001

Data is expressed as median (interquartile range). P1 is the P-value for inter group comparison; P2 is the P-value for correlation analysis with tumor regression grade grading; R is the Spearman correlation coefficient.

Table 5 Univariate analysis of subjective computed tomography signs, n (%)

CT imaging features	Chemotherapy ineffective group (n = 35)	Chemotherapy effective group (n = 62)	χ2	P value
Hickness change rate			16.524	< 0.001
< 40%	26 (74.29)	23 (37.10)
40%	9 (25.71)	39 (62.90)
Gastric wall motility			13.682	< 0.001
Present	11 (31.43)	42 (67.74)
Absent	24 (68.57)	20 (32.26)
Lesion enhancement pattern			7.845	0.005
Type A	13 (37.14)	40 (64.52)
Type B	22 (62.86)	22 (35.48)
Lymph node metastasis			2.246	0.134
N0	15 (42.86)	36 (58.06)
N+	20 (57.14)	26 (41.94)
Peritoneal thickening and nodules			6.235	0.013
None	16 (45.71)	43 (69.35)
Present	19 (54.29)	19 (30.65)

CT: Computed tomography.

Table 6 Binary logistic regression analysis of computed tomography visual signs

Item	Regression coefficient β	SE	Wald	P value	OR	95%CI
Gastric wall motility	-1.22	0.56	8.856	0.003	0.286	0.085-0.912
Thickness change rate > 40%	-1.32	0.58	10.245	< 0.001	0.265	0.078-0.935
Constant	2.15	0.42	12.468	< 0.001	8.625

Table 7 Prediction of chemotherapy efficacy by volume change rate and computed tomography visual signs model

	AUC	95%CI	Optimal cut-off value (%)	Sensitivity (%)	Specificity (%)
Tumor volume change rate	0.885	0.762-0.985	82.5	85.62	96.45
CT subjective efficacy model	0.795	0.685-0.912	75.82	62.45	83.86

CT: Computed tomography; AUC: Area under the curve.