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.