Clinical implication of FDG uptake of bone marrow on PET/CT in gastric cancer patients with surgical resection

AIM To determine the relationship between F-18 fluorodeoxyglucose(FDG) uptake of bone marrow(BM) on positron emission tomography/computed tomography(PET/CT) and clinical factors and to assess the prognostic value of FDG uptake of BM in gastric carcinoma.METHODS We retrospectively enrolled 309 gastric cancer patients who underwent staging FDG PET/CT and curative surgical resection. FDG uptake of primary tumor was visually classified as positive or negative FDG uptake. Mean FDG uptake of BM(BM SUV) and BM-to-liver uptake ratio(BLR) were measured. The relationships of BM SUV or BLR with clinical factors were evaluated. The prognostic values of BM SUV, BLR, and other clinical factors for predicting recurrence-free survival(RFS) and overall survival(OS) were assessed.RESULTS Of 309 patients, 38 patients(12.3%) experienced cancer recurrence and 18 patients(5.8%) died. Patients with advanced gastric cancer, positive FDG uptake, and recurrence had higher values of BM SUV and BLR than those with early gastric cancer, negative FDG uptake, and no recurrence(P < 0.05). BM SUV and BLR were significantly correlated with hemoglobin level, neutrophil-to-lymphocyte ratio, and platelet-tolymphocyte ratio(P < 0.05). On multivariate analysis, multiple tumors, T stage, lymph node metastasis, tumor involvement of resection margin, and BLR were significantly associated with RFS(P < 0.05). T stage, lymph node metastasis, hemoglobin level, and BLR were significantly associated with OS(P < 0.05). CONCLUSION BLR on PET/CT was an independent prognostic factor for RFS and OS in gastric cancer patients with curative surgical resection.