Prediction of NSCLC and SCLC using ki67 and the intratumoral metabolic heterogeneity assessed by 18F-FDG PET/CT

1047 Objectives: To evaluate intratumoral matabolic heterogeneity and identify whether 18F-FDG PET/CT-derived metabolic parameters of the primary tumor and ki67 could predict different pathological type of primary lung cancer.Methods:Primary tumor regions of all patients were delineated, SUVmax, SUVpeak, SUVmean, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were obtained under different SUVmax thresholds. The intratumoral metabolic heterogeneity is represented by heterogeneity factor (HF), which is obtained by calculating the derivative of the volume threshold function of the 40%-90% threshold value of SUVmax. Mann-Whitney U test analyse was used to identify whether these PET/CT parameters and ki67 significantly different in NSCLC and SCLC. The optimal cutoff value for PET/CT parameters was assessed by the receiver operating characteristic (ROC) curve to discriminate NSCLC or SCLC. Results: A total of 59 consecutive patients who were performed pretreatment 18F-FDG PET/CT and confirmed different pathological type of primary lung cancer with tracheoscope or percutaneous lung puncture biopsy, of which 21(35.6%) squamous cell carcinoma(SQCC); 25(42.4%) adenocarcinoma(ADC) and 13(22%) small cell lung cancer(SCLC), and immunohistochemistry was performed. HF (12.556±2.337; P Conclusions: HF and ki67 may predict different pathological types of primary lung cancer , especially for NSCLC and SCLC, and ki67 was better factor compared with HF. These fndings would be helpful in distinguishing patients with NSCLC or SCLC. More well-designed studies to confirm the current results and whether these parameters can further predict different types of NSCLC are needed.