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

OBJECTIVES

To investigate the role of the traditional and radiomic parameters of F-FDG PET for predicting the outcomes of patients with esophageal squamous cell carcinoma (SqCC).

METHODS

Forty-four patients with primary esophageal SqCC who underwent neoadjuvant chemoradiotherapy (CCRT) followed by esophagectomy (tri-modality treatment) were retrospectively analyzed. All patients underwent F-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.

RESULTS

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 < 0.001; HRs for DFS: 1.39 for score 2 and 6.04 for score 3, p = 0.001).This survival prediction model was superior to the traditional TNM staging system (p < 0.001 versus p = 0.061 for OS, and p = 0.001 versus p = 0.027 for DFS) and the model based on surgical pathology (p < 0.001 versus p = 0.049 for OS, and p = 0.001 versus p = 0.022 for DFS).

CONCLUSIONS

The F-FDG PET-derived radiomic parameter is useful for predicting the surgical pathological response in patients with esophageal SqCC treated with the tri-modality method. Using a combination of traditional and radiomic PET parameters with clinical profiles enables better stratification of patients into subgroups with various survival rates.