Staging of resectable lung cancer evaluation of the primary lesion and lymph node suvmax rates detected in the mediastinum to optimize treatment options during staging

Lung cancer is one of the deadly types of cancer that is increasing in frequency worldwide. Early diagnosis is of vital importance in terms of the physical effects associated with cancer and minimizing the side effects of the treatments received. This study aims to evaluate the power of primary tumor and mediastinal lymph node SUVmax ratios obtained on F-18 FDG PET/CT imaging used for preoperative staging in cases of unresectable non-small cell lung cancer (NSCLC) to predict nodal metastasis. Between 2012 and 2022, 574 cases that were diagnosed with lung cancer at Cukurova University Balcalı Hospital and underwent F-18 FDG PET/CT and were found suitable for surgery were retrospectively examined. The primary lesion size, primary lesion SUVmax, mediastinal lymph node SUVmax, TNR (tumor-to-node SUVmax ratio) and NTR (nod-to-tumor SUVmax ratio) were calculated from the PET/CT data of the cases; the relationship of these parameters with lymphovascular invasion, surgical border positivity and pathological nodal metastasis was statistically analyzed. It was found that the TNR value was significantly associated with the presence of mediastinal lymph node metastasis (p<0.05). Similarly, NTR value was also found to be associated with lymphovascular invasion (p<0.05). The cut-off values determined by ROC analyses have revealed that this ratio can be used as a prognostic indicator during the preoperative staging process. These proportional parameters and continuous variables derived from PET/CT parameters are an auxiliary biomarker for predicting nodal metastasis, lymphovascular invasion and surgical border positivity in unresectable NSCLC patients. These parameters can contribute to the determination of more accurate treatment strategies before surgical planning.