Role of ¹⁸F-FDG PET/CT in the prediction of gastric cancer recurrence after curative surgical resection.

PURPOSE

The study evaluated the role of preoperative (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in the prediction of recurrent gastric cancer after curative surgical resection.

METHODS

A total of 271 patients with gastric cancer who underwent (18)F-FDG PET/CT and subsequent curative surgical resection were enrolled. All patients underwent follow-up for cancer recurrence with a mean duration of 24 ± 12 months. (18)F-FDG PET/CT images were visually assessed and, in patients with positive (18)F-FDG cancer uptake, the maximum standardized uptake value (SUV(max)) of cancer lesions was measured. (18)F-FDG PET/CT findings were tested as prognostic factors for cancer recurrence and compared with conventional prognostic factors. Furthermore, (18)F-FDG PET/CT findings were assessed as prognostic factors according to histopathological subtypes.

RESULTS

Of 271 patients, 47 (17 %) had a recurrent event. Positive (18)F-FDG cancer uptake was shown in 149 patients (55 %). Tumour size, depth of invasion, presence of lymph node metastasis, positive (18)F-FDG uptake and SUV(max) were significantly associated with tumour recurrence in univariate analysis, while only depth of invasion, positive (18)F-FDG uptake and SUV(max) had significance in multivariate analysis. The 24-month recurrence-free survival rate was significantly higher in patients with negative (18)F-FDG uptake (95 %) than in those with positive (18)F-FDG uptake (74 %; p < 0.0001). In subgroup analysis, (18)F-FDG uptake was a significant prognostic factor in patients with tubular adenocarcinoma (p = 0.003) or poorly differentiated adenocarcinoma (p = 0.0001). However, only marginal significance was shown in patients with signet-ring cell carcinoma and mucinous carcinoma (p = 0.05).

CONCLUSION

(18)F-FDG uptake of gastric cancer is an independent and significant prognostic factor for tumour recurrence. (18)F-FDG PET/CT could provide effective information on the prognosis after surgical resection of gastric cancer, especially in tubular adenocarcinoma and poorly differentiated adenocarcinoma.