The Relationship Between Primary Tumor Metabolic Activity and Lymph Node and Distant Organ Metastasis in Non-Small Cell Lung Cancer

Objective:

In our study we aimed to evaluate the relationship of SUVmax of 18FDG uptake (metabolic activity) of the primary tumor on the pretreatment PET-CT to local invasion, lymph node metastasis and distant organ metastasis in patients with non-small cell lung cancer (NSCLC).

Method:

Hospital records of 143 patients with NSCLC who were diagnosed, followed up and treated in our thoracic oncology department between March 2009-July 2013 were retrospectively analysed. Demographic features, clinical stages, SUVmax of the primary tumor on the pretreatment PET-CT, presence of local invasion, lymph node and distant metastasis of patients were recorded.

Results:

Out of the 143 patients, 37 (25.8%) were at early stage (stage 1-2), 106 (74.2%) were at local-advanced stage (stage 3-4). The patients were divided into two groups based on SUVmax according to median SUVmax of 13.0; 69 patients (48.3%) had a SUVmax≥13 and 74 (51.7%) had a SUVmax<13. In the low-SUVmax group; 47 patients (63.5%) had lymph node metastasis, 33 (44.6%) has distant metastasis and 6 (8.1%) had both lymph node metastasis and distant metastasis. In the high-SUVmax group; 47 patients (68.1%) had lymph node metastasis, 27 (39.1%) has distant metastasis and 5 (7.2%) had both lymph node and distant metastasis. There were no statistically significant difference between the lymph node metastasis (p= 0.60) and distant metastasis (p=0.61) among the groups.

Conclusion:

In patients with NSCLC, the SUVmax at pretreatment PET-CT, which represents the metabolic activity of the tumor, can not be used in predicting the lymph node and distant metastasis.