18F-FDG PET/CT Mean SUV and Metabolic Tumor Volume for Mean Survival Time in Non-Small Cell Lung Cancer

Objective: The study was designed to determine the relationship between survival time of standardized uptake value (SUVmax and SUVmean) andmetabolic tumor volume (MTV) in patients with non-small cell lung cancer (NSCLC), and examine the impact of demographic, clinical, and radiological data of these patients on survival. Materials and Methods: We performed a retrospective analysis of the records of 79 patients with NSCLC who presented to our hospital between May 2010 and March 2013, received a final diagnosis, and underwent F-18-FDG PET/CT for staging. Clinical, radiological, and F-18-FDG PET/CT parameters with an impact on prognosis such as the SUVmax of the primary tumor as calculated by the volumetric region of interest in the F-18-FDG PET/CT scans during initial diagnosis, mean SUV of the tumor, and MTV obtained with a threshold of SUVmax greater than 2.5 were recorded and statistically analyzed. A statistical analysis was carried out based on the clinical, radiological, and PET/CT findings of the patients who were divided into 2 groups: survivors and nonsurvivors. Results: Seventy patients (88.6%) were men, and 9 (11.4%) were women. The mean age was 63.65 +/- 11.51 years in the nonsurvivor group (n = 40) versus 62.74 +/- 10.60 years in the survivor group (n = 39) (Table 1). The mean survival time from diagnosis was 7.9 +/- 6.52 months in the nonsurvivor group versus 14.09 +/- 7.41 months in the survivor group. The mean survival time was 12.9 +/- 7.9 months for those aged 60 or younger, whereas it was 9.9 +/- 7.2 years for those aged 60 or older. According to the Cox regression analysis, higher MTV [relative risk (RR), 1.006; P = 0.03] and mean SUVmax (mSUV) (RR, 1.302; P = 0.03) had a significant impact on shortening of the mean survival time. However, no statistical significance was reached for SUVmax measurements (RR, 0.970; P = 0.39). Furthermore, there was a significant relationship between increased tumor size (<2 cm, 2-4 cm, and = 4 cm) and shortened mean survival time (P = 0.03). Conclusion: The present study showed that MTV and mSUVof FDG PET/CT scans of the tumor, but not SUVmax, had a significant impact on survival time of patients with NSCLC. Based on this result, we believe that we might have more accurate information about the survival time of our patients if we also evaluate mSUV and MTV in combination with mSUV, which is frequently used for diagnosis and monitoring of patients with NSCLC during our daily practice.