Improvement in preoperative staging of gastric adenocarcinoma with positron emission tomography.
BACKGROUND
Positron emission tomography (PET) with 18- 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
Sixty-eight patients (49 males and 19 females) with gastric adenocarcinoma, who were referred for preoperative FDG-PET scans, were enrolled in this study. The patients underwent spiral-computed 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, 0.9-27.7). 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
FDG-PET improves the preoperative TNM staging of gastric adenocarcinoma. Based on its superior specificity, FDG-PET can facilitate the selection of patients for a curative resection by confirming a nodal status identified by CT.
Chen
Jian
J
Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
Cheong
Jae-Ho
JH
Yun
Mi Jin
MJ
Kim
Junuk
J
Lim
Joon Seok
JS
Hyung
Woo Jin
WJ
Noh
Sung Hoon
SH
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000556:secondary / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018279:Carcinoma, Signet Ring Cell / Q000000981:diagnostic imaging / Q000556:secondary; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010534:Peritoneal Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D049268:Positron-Emission Tomography; D011300:Preoperative Care; D011379:Prognosis; D011859:Radiography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18