Is PET-CT suitable for predicting lymph node status for gastric cancer?

Background/aims: To verify the value of PET-CT for predicting lymph node status of gastric cancer preoperatively.
Methodology: 78 gastric cancer patients accepted PET-CT preoperatively, the results of lymph node status were compared with the postoperative pathology. CT was used as control.
Results: The accuracy of PET-CT and CT in N category was 55.1% vs. 54.4%, respectively. The sensitivity, specificity, accuracy, positive predicting value (PPV), and negative predicting value (NPV) of PET-CT in predicting position of positive lymph node were 31.0%, 97.2%, 61.5%, 92.9%, and 54.7%, respectively. While for CT, were 60.5%, 83.3%, 70.6%, 82.1%, and 62.5%, respectively. For tier 1 lymph node metastasis, the sensitivity, specificity, accuracy, PPV, and NPV of PET-CT were 31.6%, 95.0%, 64.1%, 85.7%, and 59.4%, respectively. While for CT, were 60.0%, 78.8%, 69.1%, 75.0%, and 65.0%, respectively. The sensitivity of CT was significantly better (p = 0.031). For tier 2 or tier 3 lymph node metastasis, the sensitivity, specificity, accuracy, PPV, and NPV of PET-CT were 12.0%, 98.1%, 70.5%, 75.0%, and 70.3%, respectively. While for CT, were 22.7%, 93.5%, 70.6%, 62.5%, and 71.7%, respectively, without significance.
Conclusions: PET-CT is not sensitive enough to predict the regional lymph node status of gastric cancer preoperatively.