Background: This study investigated the prognostic value of diffuse splenic uptake on F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in gastric cancer (GC) patients.
Methods: A total of 134 pathology confirmed GC patients who underwent PET/CT for staging work-ups were enrolled. The maximal standardized uptake value (SUVmax) of primary tumor (Tmax), spleen (Smax), and spleen to liver uptake ratio (SLR) were measured. The prognostic value of PET-measured parameters in GC patients for predicting recurrence-free survival (RFS) and overall survival (OS) were assessed. And the relationships of the parameters with hematological and inflammatory parameters were also investigated.
Results: During follow-up period, 19 patients (14.1%) had disease recurrence and 12 (8.9%) died from GC. In univariate analysis, hematocrit (p<0.001 and p = 0.002), neutrophil to lymphocyte ratio (NLR; p = 0.021 and p = 0.040), AJCC staging (p<0.001 and p<0.001), adjuvant chemotherapy (p<0.001 and p<0.001), Tmax (p = 0.004 and p = 0.005), and SLR (p = 0.005 and p = 0.016) were significant prognostic factors for RFS and OS, whereas platelet to lymphocyte ratio (PLR; p = 0.034) was a significant prognostic factor for RFS. In multivariate analysis, only SLR was an independent prognostic factor for RFS (p = 0.018, adjusted HR = 3.011, 95% CI = 1.207-7.511). SLR were significantly associated with serum hematocrit level (r = -0.256, p = 0.002), PLR (r = 0.362, p = 0.001), and Tmax (r = 0.280, p = 0.001).
Conclusion: Diffuse splenic uptake on FDG PET/CT was correlated with the level of hematological and inflammatory parameters and was an independent predictor for RFS in GC.