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

Abstract

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-to-lymphocyte 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.

Keywords: Bone marrow; F-18 fluorodeoxyglucose; Gastric cancer; Positron emission tomography; Prognosis.

Figure 1

F-18 fluorodeoxyglucose positron emission tomography/computed tomography images of a gastric cancer patient with diffusely increased F-18 fluorodeoxyglucose uptake of bone marrow. A: Maximum intensity projection; B and C: Coronal and transaxial PET images; D: Transaxial CT image; E: Fused transaxial PET/CT image of a 71-year-old woman with advanced gastric cancer. Focal intensely increased FDG uptake was observed in the primary tumor lesion of stomach with Tmax of 8.36 (arrow). BM of the patient showed increased FDG uptake with BM SUV of 2.36 and BLR of 1.25. The patient underwent total gastrectomy. The cancer recurred 13.4 mo after the treatment and the patient died 18.5 mo after the operation. PET/CT: Positron emission tomography/computed tomography; FDG: F-18 fluorodeoxyglucose; BM: Bone marrow; BLR: BM-to-liver uptake ratio.

Figure 2

F-18 fluorodeoxyglucose positron emission tomography/computed tomography images of a gastric cancer patient with minimally increased F-18 fluorodeoxyglucose uptake of bone marrow. A: Maximum intensity projection; B and C: Coronal and transaxial PET images; D: Transaxial CT image; E: Fused transaxial PET/CT image of a 75-year-old woman with advanced gastric cancer. Focal intensely increased FDG uptake was observed in the primary tumor lesion of stomach with Tmax of 7.57 (arrow). BM SUV and BLR were 1.12 and 0.54, respectively. The patient underwent total gastrectomy. The patient is still alive without cancer recurrence with a follow-up period of 35.5 mo. PET/CT: Positron emission tomography/computed tomography; FDG: F-18 fluorodeoxyglucose; BM: Bone marrow; BLR: BM-to-liver uptake ratio.

Figure 3

Kaplan-Meier survival curves for recurrence-free survival and overall survival. A: Recurrence survival curve according to T stage; B: Overall survival curve according to T stage; C: Recurrence-free survival curve according to BLR; D: Overall survival curve according to BLR. BLR: Bone marrow-to-liver uptake ratio.