Development and Validation of CT-based Radiomics Scores for Prediction of Response to Neoadjuvant Chemotherapy and Survival in Gastric Cancer
Abstract Background: Neoadjuvant chemotherapy is a promising treatment option for potential resectable gastric cancer, but patients’ responses varied. We aimed to develop and validate a radiomics score (rad_score) to predict the treatment response of neoadjuvant chemotherapy, and to investigate its efficacy in survival stratification. Methods: A total of 106 patients with neoadjuvant chemotherapy before gastrectomy were included (training cohort: n=74; validation cohort: n=32). Radiomics features were extracted from the pre-treatment portal venous-phase CT. After feature reduction, a rad_score was established by Randomized Tree algorithm. A rad_clinical_score was constructed by integrating the rad_score with clinical variables, so was a clinical score by clinical variables only. The three scores were validated regarding their discrimination and clinical usefulness. According to the score thresholds (updated with post-operative clinical variables), patients were stratified into two groups and their survivals were compared.Results: In the validation cohort, the rad_score demonstrated a good predicting performance in treatment response of neoadjuvant chemotherapy (AUC [95% CI] =0.82 [0.67, 0.98]), which was better than the clinical score (based on pre-operative clinical variables) without significant difference (0.62 [0.42, 0.83], P=0.09). The rad_clinical_score could not further improve the performance of rad_score (0.70 [0.51, 0.88], P=0.16). Based on the thresholds of these scores, the high-score groups all achieved better survivals than the low-score groups in the whole cohort (all P<0.001). Conclusion: The rad_score was effective in predicting treatment response of neoadjuvant chemotherapy and stratifying patients’ survival for gastric cancer, which assisted in individualized treatment planning.