Prognostic Value Of The Volumetric Parameters Of Dual-Time-Point F-18-Fdg Pet/Ct In Non-Small Cell Lung Cancer Treated With Definitive Radiation Therapy

OBJECTIVE. The purpose of this study is to assess the effectiveness of the volumetric parameters of dual-time-point imaging (DTPI) with F-18-FDG PET (DTPI FDG PET) in predicting the prognosis of patients with non-small cell lung cancer (NSCLC) treated with definitive radiation therapy (RI).MATERIALS AND METHODS. The records of consecutive patients who received definitive RT for NSCLC from April 2010 to April 2017 were retrospectively reviewed. Pretreatment DTPI FDG PET images were routinely obtained as part of the PET/CT examination. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor (SUVmax-T, MTV-T, and TLG-T, respectively) and those of the primary tumor and lymph nodes (N) combined (SUVmax-TN, MTV-TN, and TLG-TN, respectively) were used as variables, and the percentage change in these parameters (change in SUVmax [Delta SUVmax], change in MTV [MTV], and change in TLG [Delta TLG]) on DTPI PDC; PET were analyzed.RESULTS. Of the 118 patients identified and reviewed, 59 met the study eligibility criteria. After a median follow-up of 23.3 months, the 3-year local control rate (I ,CR) and disease-specific survival rates were 53.5% and 45.0%, respectively. On multivariate analysis, significant predictors of LCR were TLG-T and change in TLG-TN (Delta TLG-TN), and significant predictors of disease-specific survival were adjuvant chemotherapy, treatment response, TLG-T, and change in TLG-T (Delta TLG-T). Low percentage changes in Delta TLG (< 41.0% for Delta TLG -T and < 32.0% for Delta TLG TN) correlated with poor LCR and disease-specific survival. SUV. and MTV were not significant predictors of both LCR and disease-specific survival.CONCLUSION. TLG and Delta TLG were significant prognostic factors in patients with NSCLC treated with definitive RT. In particular, a relatively low Delta TLG resulted in poor outcomes in terms of LCR and disease-specific survival.