Objectives Reliable pretreatment prediction of pathological response remains a major challenge in locally advanced gastric cancer (LAGC). This study evaluated whether quantitative parameters from multiphasic contrast-enhanced CT (CECT) can predict tumor regression grade (TRG) after neoadjuvant chemotherapy (NAC) and provide prognostic information. Methods We retrospectively analyzed 116 patients with cT2-4NxM0 gastric adenocarcinoma treated with NAC treatment followed by gastrectomy between January 2019 and December 2024. Quantitative imaging variables included phase-specific tumor attenuation (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\:{CT}_{p}^{Tumor},\:p=NE,AP,\:VP,\:DP)\)</EquationSource> </InlineEquation>, normalized enhancement difference (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\:{Norm\varDelta\:CT}_{p}^{Tumor},\:p=AP,\:VP,\:DP\)</EquationSource> </InlineEquation>), normalized enhancement rate (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\:{NormRate}_{p}^{Tumor},\:p=AP,\:VP,\:DP\)</EquationSource> </InlineEquation>), tumor area, and enhancement pattern. TRG was assessed on surgical specimens using the Mandard system; responders were defined as TRG 1–2 and non-responders as TRG 3–5. Candidate variables were screened by univariate analysis and Spearman correlation, then enrolled into weighted multivariable logistic regression with 5-fold cross-validation. Associations with overall survival were evaluated using univariate Cox and Kaplan-Meier analyses. Results Forty-one patients were responders and 75 were non-responders. CA199, CEA, and age were independent clinical predictors. Among imaging features, venous-phase tumor attenuation (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\:{CT}_{VP}^{Tumor}\)</EquationSource> </InlineEquation>; OR = 8.809, 95% CI: 2.134–36.358, P = 0.003) and arterial-phase normalized enhancement rate (<InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\:{NormRate}_{AP}^{Tumor}\)</EquationSource> </InlineEquation>; OR = 3.200, 95% CI: 1.365–7.504, P = 0.007) independently predicted TRG response. The clinical, imaging, and combined models achieved mean AUCs of 0.746, 0.807, and 0.869, respectively; the combined model showed the best overall discrimination (accuracy 0.759, sensitivity 0.703, specificity 0.787) with good calibration. Higher <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\:{NormRate}_{DP}^{Tumor}\)</EquationSource> </InlineEquation> (HR = 1.01, P = 0.004) and <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(\:{NormRate}_{VP}^{Tumor}\)</EquationSource> </InlineEquation> (HR = 1.01, P = 0.043) were associated with worse overall survival. Conclusion Pretreatment CECT-derived quantitative features can predict TRG response in LAGC, and a combined clinical–imaging model improves predictive performance. Higher normalized enhancement rates in the venous and delayed phases are associated with poorer overall survival, supporting pre-treatment risk stratification in clinical practice.

Pretreatment multiphasic contrast-enhanced CT predicts tumor regression grade and survival in locally advanced gastric cancer

期刊论文
发表日期：

2026年4月20日

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Youqiang Hu,
Mengli Xia,
Longquan Zou,
Wenqi He,
Yuan-lin Zhang,
Lin Lan,
Mixue Sun,
Yu Zhuang,
Wenbin Wang,
Ping Jiang

摘要

Objectives

Reliable pretreatment prediction of pathological response remains a major challenge in locally advanced gastric cancer (LAGC). This study evaluated whether quantitative parameters from multiphasic contrast-enhanced CT (CECT) can predict tumor regression grade (TRG) after neoadjuvant chemotherapy (NAC) and provide prognostic information.

Methods

We retrospectively analyzed 116 patients with cT2-4NxM0 gastric adenocarcinoma treated with NAC treatment followed by gastrectomy between January 2019 and December 2024. Quantitative imaging variables included phase-specific tumor attenuation ( \(\:{CT}_{p}^{Tumor},\:p=NE,AP,\:VP,\:DP)\) , normalized enhancement difference ( \(\:{Norm\varDelta\:CT}_{p}^{Tumor},\:p=AP,\:VP,\:DP\) ), normalized enhancement rate ( \(\:{NormRate}_{p}^{Tumor},\:p=AP,\:VP,\:DP\) ), tumor area, and enhancement pattern. TRG was assessed on surgical specimens using the Mandard system; responders were defined as TRG 1–2 and non-responders as TRG 3–5. Candidate variables were screened by univariate analysis and Spearman correlation, then enrolled into weighted multivariable logistic regression with 5-fold cross-validation. Associations with overall survival were evaluated using univariate Cox and Kaplan-Meier analyses.

Results

Forty-one patients were responders and 75 were non-responders. CA199, CEA, and age were independent clinical predictors. Among imaging features, venous-phase tumor attenuation ( \(\:{CT}_{VP}^{Tumor}\) ; OR = 8.809, 95% CI: 2.134–36.358, P = 0.003) and arterial-phase normalized enhancement rate ( \(\:{NormRate}_{AP}^{Tumor}\) ; OR = 3.200, 95% CI: 1.365–7.504, P = 0.007) independently predicted TRG response. The clinical, imaging, and combined models achieved mean AUCs of 0.746, 0.807, and 0.869, respectively; the combined model showed the best overall discrimination (accuracy 0.759, sensitivity 0.703, specificity 0.787) with good calibration. Higher \(\:{NormRate}_{DP}^{Tumor}\) (HR = 1.01, P = 0.004) and \(\:{NormRate}_{VP}^{Tumor}\) (HR = 1.01, P = 0.043) were associated with worse overall survival.

Conclusion

Pretreatment CECT-derived quantitative features can predict TRG response in LAGC, and a combined clinical–imaging model improves predictive performance. Higher normalized enhancement rates in the venous and delayed phases are associated with poorer overall survival, supporting pre-treatment risk stratification in clinical practice.