Interim analysis of fluorodeoxyglucose uptake in patients with metastatic or recurrent gastric cancer treated with fluoropyrimidine based chemotherapy.

Abstract

44 Background: The role of 18F-FDG PET/CT scanning in advanced gastric cancer (AGC) is still under investigation. We evaluated its prognostic role in patients with recurrent or metastatic AGC who received fluoropyrimidine based chemotherapy. Methods: Forty-six patients with metastatic or recurrent AGC who had the baseline and interim PET/CT scanning during the palliative chemotherapy were analyzed. The lesion with the highest SUVmax value among target lesions was determined to be a main target (SUVmax1), and interim SUVmax of the target lesion was measured after several cycles (4-12 cycles) of chemotherapy (SUVmax2). The formula calculating metabolic change follows: ΔSUVmax2-SUVmax1 (%) = (SUVmax2-SUVmax1)/SUVmax1 * 100 Results: Patients with SUVmax1 value > 6 had a significantly higher response rate than those with the lower SUVmax1 (73.9% vs. 26.1%, p=0.036). SUVmax2 < 5 was significantly associated with better overall survival (OS) (p=0.035) with univariate analysis. ΔSUVmax2- SUVmax1 > -20% or appearance of new lesions with 18F-FDG PET/CT scanning at interim analysis was significantly associated with worse OS (p=0.027). ΔSUVmax2- SUVmax1 > -20% or new lesions (p=0.03) was the only factor significantly independently associated with OS using multivariate analysis (Table). Female (p=0.028), SUVmax2 > 5 (p=0.002), and ΔSUVmax2-SUVmax1 value > -20% (p=0.004) were significantly associated factors with worse progression free survival (PFS) using univariate analysis. Both SUVmax2 (p=0.028) and ΔSUVmax2-SUVmax1 value (p=0.043) were the significant factors associated with PFS using multivariate analysis. Conclusions: Analysis ofmetabolic change by interim PET/CT scanning is useful in predicting prognosis in patients with recurrent or metastatic AGC undergoing fluoropyrimidine based chemotherapy. [Table: see text]