Objective To investigate the value of ¹⁸F-FDG PET/CT in the detection of gastric cancer recurrence and metastasis.

Methods A retrospective analysis involving 52 patients with suspected recurrence and metastasis after gastric cancer surgery and who underwent ¹⁸F-FDG PET/CT and contrast-enhanced CT examinations over the period of January 2013 to August 2017 was performed, including 40 males and 12 females, aged between 30 and 86 years old(61.73±11.44). Receiver operating characteristic analysis was conducted on the basis of imaging data for the detection of a cutoff SUV_max value that is indicative of the presence of recurrent lesions. Differences among groups were determined through the t-test. The results of different methods were compared through the χ² test.

Results The specificity of ¹⁸F-FDG PET/CT was favorable and was higher than that of the qualitative analytical method(χ²=5.439, P<0.05) when a cutoff of 3.14 was used to evaluate for anastomosis. The SUV_max of anastomotic recurrence was higher than that of anastomotic inflammation(t=4.701, P<0.05). The sensitivity of ¹⁸F-FDG PET/CT in diagnosing recurrence, lymph node metastasis and distant metastasis was higher than that of contrast-enhanced CT, the difference was statistically significant(90.48% vs.23.81%, 92.00% vs.60.00%, 87.50% vs.34.38%, χ²=19.369, 5.373, 16.804, all P<0.05). The specificity of ¹⁸F-FDG PET/CT and contrast-enhanced CT in diagnosing recurrence, lymph node metastasis and distant metastasis was not statistically significant(100% vs.100%, 100% vs.92.5%, 100% vs.95.00%, χ²=0.000, 2.850, 1.412, all P>0.05).

Conclusions The performance of PET/CT in the diagnosis of gastric cancer recurrence and metastasis is better than that of contrast-enhanced CT. Therefore, ¹⁸F-FDG PET/CT imaging has a high clinical value in the postoperative detection of gastric cancer.