Statistical analysis:
The Statistical Package for Social Sciences (SPSS) version 22.0 for Windows (SPSS Inc. Chicago, USA) software package was used for the statistical analysis of the study data. If the data were non-normally distributed, the Mann-Whitney U test was used for comparison of two groups, and the Kruskal-Wallis test was used for comparison of 3 groups and more. Pearson’s chi-squared test, Fisher’s chi-squared test, and Continuity Correction chi-square test were used for comparison of categorical variables among independent groups. The correlation between tumor size, Fuhrman grade, stage, and metabolic measurements was analyzed by Spearman’s Correlation test. In this study, the level of statistical significance was set at p<0.05.