Abstract
BACKGROUND
Positron emission tomography (PET) with 18β fluorodeoxyglucose (FDG) has been used to both detect and stage a variety of malignancies. The current study examined the value of PET for preoperative staging of gastric adenocarcinoma.
METHODS
Sixtyβeight patients (49 males and 19 females) with gastric adenocarcinoma, who were referred for preoperative FDGβPET scans, were enrolled in this study. The patients underwent spiralβcomputed tomography (CT) within 1 week of referral. The final diagnosis in all patients was made by histologic and surgical findings. For quantitative PET analysis, the regional tumor FDG uptake was measured by the standardized uptake value (SUV).
RESULTS
For the primary tumor of a gastric adenocarcinoma, PET demonstrated an increased uptake in 64 of 68 patients (sensitivity, 94%), with a mean SUV of 7.0 (range, 0.9β27.7). A comparison of FDG uptake and clinicopathologic features showed significant association between FDG uptake and macroscopic type, tumor size, lymph node metastasis, histologic type, and TNM stage. The PET scan had a similar accuracy with that of CT for diagnosing local and distant lymph node metastases as well as peritoneal status. In assessing local lymph node status, however, PET had a higher specificity than CT (92% vs. 62%, P = 0.000). Moreover, PET had additional diagnostic value in 10 (15%) of 68 patients by upstaging 4 (6%) and downstaging 6 (9%) patients. PET combined with CT was more accurate for preoperative staging than either modality alone (66% vs. 51%, 66% vs. 47%, respectively; P = 0.002).
CONCLUSIONS
FDGβPET improves the preoperative TNM staging of gastric adenocarcinoma. Based on its superior specificity, FDGβPET can facilitate the selection of patients for a curative resection by confirming a nodal status identified by CT. Cancer 2005. Β© 2005 American Cancer Society.