Combining the radiomic features and traditional parameters of 18F-FDG PET with clinical profiles to improve prognostic stratification in patients with esophageal squamous cell carcinoma treated with neoadjuvant chemoradiotherapy and surgery

To investigate the role of the traditional and radiomic parameters of 18F-FDG PET for predicting the outcomes of patients with esophageal squamous cell carcinoma (SqCC). Forty-four patients with primary esophageal SqCC who underwent neoadjuvant chemoradiotherapy (CCRT) followed by esophagectomy (tri-modality treatment) were retrospectively analyzed. All patients underwent 18F-FDG PET/CT before and after neoadjuvant CCRT. The radiomic features were calculated using the pre-treatment PET scan. Pre-treatment radiomic features and changes in the PET-derived traditional parameters after neoadjuvant CCRT were analyzed according to the pathological response to esophagectomy, disease-free survival (DFS), and overall survival (OS). We further developed a scoring system based on the independent survival prognosticators and compared our model to the traditional TNM staging system and surgical pathology. A pre-treatment primary tumor histogram entropy ≥ 3.69 predicts an unfavorable response to neoadjuvant CCRT (OR = 19.25, p = 0.009). An SUVmax reduction ratio ≤ 0.76, a pre-treatment primary tumor code similarity ≤ 0.0235, and incomplete pathological remission were independently associated with poor OS (p = 0.019, 0.033, and 0.038, respectively) and DFS (p = 0.049, 0.021, and 0.009, respectively). The three survival prognosticators were used to construct a scoring system (score 0–1, 2, and 3). Patients with a score of 2 or 3 had a significantly worse survival outcome than those with a score of 0–1 (HRs for OS: 3.58 for score 2, and 15.19 for score 3, p