Predictive Value of Primary Fluorine-18 Fluorodeoxyglucose Standard Uptake Value for a Better Choice of Systematic Nodal Dissection or Sampling in Clinical Stage IA Non-Small-Cell Lung Cancer

The aim of this study was to determine whether the standard uptake value of primary tumor on positron emission tomography can predict lymph node metastasis in clinical stage I non-small-cell lung cancer. Data of 144 patients were collected from 5 centers and showed that the positron emission tomography standard uptake value might be a potential predictor, which adds more evidence for lymph node sampling. Purpose: To determine whether the standard uptake value (SUV) of the primary lesion can predict mediastinal lymph node metastasis in clinical stage IA non-small-cell lung cancer (NSCLC). Materials and Methods: At 5 centers, patients with clinical stage IA NSCLC from February 2004 to August 2010 were analyzed retrospectively. Data from Shandong Cancer Hospital and from the Cancer Hospital Affiliated to Harbin Medical University were used as a testing set, and data from the other 3 institutions were used as the validation set. Final diagnosis was established based on the histopathologic examination. Results: Data from 144 patients were collected for the study. The primary results in our study showed that maximal SUV (SUVmax) of primary tumor might be a predictor of lymph node metastasis (chi(2) = 10.424; P=.001) and the best cutoff value was 7.25 (P=.029). For the testing set, lymph node metastasis rates in low-grade group (SUVmax < 7.25) and high-grade group (SUVmax > 7.25) were 5% (2/43) and 36% (9/25) (P=.001) For the total data set, lymph node metastasis rate was 7% (6/93) in low-grade group (SUVmax < 7.25) and 26% (13/51) in high-grade group (SUVmax > 7.25) (chi(2) = 10.424; P=.001). A multivariate analysis revealed that no factors were applied to predict the probability of metastasis. But the analysis showed a weak correlation between SUVmax and nodal status (r = 0.21; P=.011) with bivariate correlation. Conclusion: Analysis of our data suggested that fluorine-18 fluorodeoxyglucose SUVmax of the primary tumor might be a predictor of lymph node involvement in stage IA NSCLC. The rate of mediastinal lymph node metastasis of patients with a lower fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography SUVmax might be relatively low, which provides more evidence for clinical procedures of clinical stage IA NSCLC.