The value of ¹⁸F-FDG SPECT-CT in detecting recurrence and metastasis of gastric carcinoma

Objective To evaluate the clinical value of ¹⁸F-FDG SPECT-CT in detecting recurrence and metastasis of gastric cancer.

Methods Analyzed the SPECT-CT imaging data in 122 cases with gastric cancer retrospectively, and then combined with the results of pathological examination, of which 79 cases compared with the same period of enhanced CT and the joint inspection of the two by each other in the remnant stomach or anastomotic recurrence of diagnostic performance; 109 cases with the comparison of stomach tumor markers and the joint inspection of the two by each other in the diagnosis of metastatic evaluation of performance.SPSS13.0 software package was used to perform χ²test and fisher's exact probability.

Results ① The sensitivity, specificity, positivity predicitive value(PPV), negativepredictivevalue(NPV), andaccuracy of ¹⁸F-FDG SPECT-CT in diagnosing residual stomach or anastomotic recurrence was 84.0%, 96.3%, 91.3%, 92.9%and 92.4%respectively.Those of enhanced CT was 58.3%, 78.2%, 53.8%, 81.1%and 72.2%respectively.The former of which the sensitivity, specificity, PPV and accuracy were significantly higher than enhanced CT, and the difference was statistically significant(χ²=3.953~11.805, all P < 0.05).Although theNPV is higher than enhanced CT, the difference was not statistically significant(χ²=3.344, P > 0.05).Joint diagnosis of the two indicators was 88.0%, 98.1%, 95.7%, 94.6%and 94.9%respectively, significantly higher than the enhanced CT, and the difference was statistically significance(χ²=4.732~10.341, all P < 0.05).Although the indicators were higher than ¹⁸F-FDG SPECT-CT, the difference was not statistically significant(all χ²=0.000, P > 0.05).②The sensitivity, specificity, PPV, NPV, and accuracy of ¹⁸F-FDG SPECT-CT in diagnosing metastasis of gastric cancer was 92.9%, 87.5%, 96.3%, 80.8%and 91.7%respectively.Those of gastric tumor markers was 81.2%, 75.0%, 92.0%, 52.9%and 79.8%.Where the former sensitivity, NPV and accuracy were significantly higher than the stomach tumor markers, the difference was statistically significant(χ²=4.026~6.355, all P < 0.05). Although specificity and PPV were higher than the gastric tumor markers, the difference was not statistically significant(χ²=0.574, 0.681, P > 0.05).The two combined diagnostic indicators was 96.5%, 83.3%, 95.3%, 87.0%and 93.6%respectively, similarly with the ¹⁸F-FDG SPECT-CT, and the difference was not statistically significant(χ²=4.026~6.355, all P > 0.05), but significantly higher than the gastric tumor markers, and the sensitivity, NPV and accuracy of the difference was statistically significant(χ²=7.143~10.014, all P < 0.05).

Conclusion ¹⁸F-FDG SPECT-CT has greater clinical value in detecting recurrence and metastasis of gastric cancer.