Background: This study used low-dose computed tomography (CT) perfusion imaging technology to evaluate the efficacy of neoadjuvant chemotherapy in patients with advanced gastric adenocarcinoma and to determine whether any of the perfusion parameters could predict tumor response to chemotherapy.
Methods: Forty patients with gastric adenocarcinoma (T3-4NxM0) received three cycles of neoadjuvant chemotherapy and low-dose spiral CT perfusion imaging prior to and after the first and third series of chemotherapy. We calculated tissue blood flow (BF) and blood volume (BV) using commercial software. One-way analysis of variance (ANOVA) was used to detect any significant variation of the tested parameters between different times of scanning. Spearman's test was used to evaluate the correlation among perfusion parameters, tumor size and pathological efficacy grade, and clinical response after chemotherapy, respectively. A receiver-operating characteristic analysis was used to determine the optimal diagnostic cutoff value for changes in perfusion parameters and tumor size.
Results: One-way ANOVA showed significant differences in BF and BV values between those before and after chemotherapy (p < 0.01). The BF, BV and size reduction rate after three series of chemotherapy were significantly correlated with pathological efficacy grade. BF and BV values after the first and third series of chemotherapy were also significantly correlated with clinical response (p < 0.01, respectively). The diagnostic sensitivity and specificity of the BV reduction rate were higher than those of size reduction rate.
Conclusions: Low-dose CT perfusion imaging is a valuable tool that permits microcirculation evaluation and therefore can evaluate the efficacy of neoadjuvant chemotherapy in patients with advanced gastric adenocarcinoma.
Keywords: Clinical response; Gastric adenocarcinoma; Low-dose CT perfusion imaging; Neoadjuvant chemotherapy; Pathological response.