Prediction of lymph node metastasis using the maximum-standardized uptake value (max-SUV) by preoperative positron emission tomography-computed tomography (PET/CT) in gastric cancer

Objectives Even though PET/CT is not the appropriate first-line diagnostic modality for the preoperative staging of gastric cancer and complete resection coupled with radical lymph node dissection is the standard therapeutic method in gastric cancer, the accurate assessment of tumor invasion, tumor size, nodal involvement and distant metastasis is critical to the optimal treatment plan and prognosis. The aim of this study was to assess the relation of lymph node metastasis and clinicopathologic parameters such as tumor location, tumor differentiation and max-SUV of primary tumor.

Methods Over a 3-year period, we reviewed the preoperative PET/CT of 63 patients who underwent gastrectomy in this retrospective study. Image analysis was performed with both visual interpretation and using a semiquantitative method, maximum standardized uptake values (max-SUV). Statistical analysis was performed to evaluate the relations between clinicopathologic parameters including max-SUV and lymph node metastasis using logistic regression analysis. A p-value of < 0.05 was considered statistically significant.

Results According to multiple logistic regression, the lymph node metastasis was not associated with tumor location and tumor differentiation. (P = 0.27 and P = 0.97, respectively). But there was significant correlation between lymph node metastasis and max-SUV (P < 0.05).

Conclusions Higher max-SUV of primary tumor was found to be significantly correlated with the more lymph node metastasis. Although PET/CT may be of limited use in lymph node assessment for metastasis spread, the high max-SUV help the physician consider the range of the locoregional staging