International Journal of Hematology and Oncology 2019, Vol 29, Num 4 Page(s): 218-222
Are Ratio of Lymph Node to Primary Focus SUV-max and PET/CT 18FDG Standard Uptake Value of Lymph Nodes Meaningful in Staging Non-Small Cell Lung Cancer?

A. Kadri CIRAK1, Kenan C. CEYLAN2, Deniz AKPINAR2, Seyda O KAYA2, Hakan KOPARAL3

1Izmir Dr. Suat Seren Research and Training Hospital of Chest Diseases and Thoracic Surgery, Department of Chest Diseases, Izmir, TURKEY
2Izmir Dr. Suat Seren Research and Training Hospital of Chest Diseases and Thoracic Surgery, Department of Thoracic Surgery, Izmir, TURKEY
3Izmir Dr. Suat Seren Research and Training Hospital of Chest Diseases and Thoracic Surgery, Department of Nucleer Medicine, Izmir, TURKEY

Keywords: Non-small cell lung cancer, Staging, 18FDG, PET/CT
Surgical treatment for mediastinal lymph node involvement in non-small cell lung cancer (NSCLC) will not have positive impact on survival. The present study aimed at investigating the role of positron emission tomography/computerized tomography (PET/CT) in staging NSCLC. Ninety-nine patients with maximal standard mediastinal lymph node involvement value (SUVmax) of 2.5 or more on PET/CT scanning were included in this study. All patients underwent invasive staging or pathological staging with direct thoracotomy. Relationship between lymph node SUVmax and lymph node/primary mass SUVmax ratio and presence of lymph node metastasis was investigated. Mean SUVmax ratio was 3.87 in the group with positive mediastinal lymph node on PET/CT but pathologically benign lymph nodes whereas it was 5.69 in those with pathologically malignant lymph nodes. Although there was a numeric difference between two groups, the difference was statistically insignificant (p= 0.65). Lymph node/mass SUVmax ratio was 0.49 in the patients with positive lymph nodes on PET/CT and benign pathology whereas it was 0.65 in those with malignant pathology and the difference between them was found to be not significant (p= 0.61). It was observed, however, that as SUVmax ratio increased, possibility of detecting malignant lymph node raised. Rate of malignancy was 52.38% in the group with SUVmax ratio of 0.1 to 0.3 whereas it was 91.66% in those with SUVmax ratio of 1 or greater. No significant relationship was found between lymph node SUVmax rate and presence of metastatic lymph node. We believe that more multi-center studies are needed with more patients.