Does the Computed Tomography Hounsfield Units Change Predict Response to Perioperative Chemotherapy in Patients with Gastric Adenocarcinoma

Purpose: We aimed to investigate whether Computed Tomography (CT) attenuation change is predictive of poor pathological response in patients with gastric cancer (GC) and gastroesophageal junction (GEJ) adenocarcinoma who received perioperative fluorouracil (FU), leucovorin (LV), oxaliplatin, and docetaxel (FLOT) regimen. Methods: This trial was planned as a retrospective single-center study. In the neoadjuvant setting, patients received a regimen that includes docetaxel (50 mg/m²), oxaliplatin (85 mg/m²), and LV (200 mg/m²) with short-term infusional FU (2600 mg/m² as a 24-hour infusion), on day 1 and administered every two weeks for four cycles. Patients were classified as response rates according to the CAP-TRG system (0-1 response or 2-3 response) after completing four cycles of the FLOT regimen. Results: In total, 108 patients with GC and GEJ adenocarcinoma were included in the study. In a univariate analysis, age, histologic grade, T stage, N stage, and change in attenuation were found to be the statistically significant factors (p = 0.034, p =0.038, p = 0.001, p =0.029, and p = 0.022, respectively). In a multivariate analysis, T4 tumors and a higher change in attenuation were found to be important factors associated with poor pathologic response (p = 0.027 and p = 0.038, respectively). Conclusion: Our results demonstrate that a higher decrease in CT attenuation and T4 tumors is associated with a poor response to perioperative FLOT chemotherapy in patients with GC and GEJ adenocarcinoma.