18F-2-Deoxy-2-Fluoro-D-Glucose Positron Emission Tomography: Computed Tomography for Preoperative Staging in Gastric Cancer Patients

Abstract

PurposeThe use of 18F-2-deoxy-2-fluoro-D-glucose positron emission tomography-computed tomography as a routine preoperative modality is increasing for gastric cancer despite controversy with its usefulness in preoperative staging. In this study we aimed to determine the usefulness of preoperative positron emission tomography-computed tomography scans for staging of gastric cancer.Materials and MethodsWe retrospectively analyzed 396 patients' positron emission tomography-computed tomography scans acquired for preoperative staging from January to December 2009.ResultsThe sensitivity of positron emission tomography-computed tomography for detecting early gastric cancer was 20.7% and it was 74.2% for advanced gastric cancer. The size of the primary tumor was correlated with sensitivity, and there was a positive correlation between T stage and sensitivity. For regional lymph node metastasis, the sensitivity and specificity of the positron emission tomography-computed tomography were 30.7% and 94.7%, respectively. There was no correlation between T stage and maximum standardized uptake value or between tumor markers and maximum standardized uptake value. Fluorodeoxyglucose uptake was detected by positron emission tomography-computed tomography in 24 lesions other than the primary tumors. Among them, nine cases were found to be malignant, including double primary cancers and metastatic cancers. Only two cases were detected purely by positron emission tomography-computed tomography.ConclusionsPositron emission tomography-computed tomography could be useful in detecting metastasis or another primary cancer for preoperative staging in gastric cancer patients, but not for T or N staging. More prospective studies are needed to determine whether positron emission tomography-computed tomography scans should be considered a routine preoperative imaging modality.

Initial Standardized Uptake Value of Positron Emission Tomography Influences the Prognosis of Patients with Localized Gastric Adenocarcinoma Treated Preoperatively

“…Prior reports using the Lauren classification have shown that FDG-PET/CT had significantly lower sensitivity in detecting diffuse type, SRC, and mucinous GACs than intestinal type adenocarcinomas. [9, 24–27] Low iSUV as a poor prognosticator may be due to lack of avidity in diffuse type of GAC [9, 28] and low expression of glucose transporter 1 (GLUT1). [9, 25, 29]…”

Improving Patient Selection for 18F-FDG PET Scanning in the Staging of Gastric Cancer

“…Several studies reported that the Lauren intestinal type of gastric cancer had higher 18 F-FDG uptake than the diffuse type (12,13,23,24). Low 18 F-FDG uptake in some gastric cancers may be explained by high extracellular mucin content and more dispersed and diluted tumor cells.…”

“…The low spatial resolution of PET and the physiologic uptake of 18 F-FDG by benign processes such as gastritis, or simply physiologic uptake in the muscularis mucosae, make it difficult to detect early small-volume gastric cancer through a combination of partial-volume effects and high adjacent background activity. Similarly, greater depth of tumor invasion and the presence of nodal disease have been correlated with tumoral 18 F-FDG uptake (13,23,30).…”

Preoperative Use of PET/CT in Patients With Colorectal and Gastric Cancer and Its Impact on Treatment Decision Making

“…7 Additionally, early gastric cancer has a very low detection rate of 20%. 19 Only 2 of the 8 gastric tumors with low affinity did not uptake FDG in our series. Five patients (8%) had stage I cancer; thus, staging had no influence on our results.…”

“…Similar rates 11,18 are usually observed in other gastric cancer studies, but lesser rates (60%) were also observed. 19 Signet ring cell and mucinous carcinomas express very low levels of GLUT-1 (glucose transporter 1) receptor and 18F-FDG uptake mostly related to this receptor's levels. 7 Additionally, early gastric cancer has a very low detection rate of 20%.…”