The efficiency of ¹⁸F-FDG PET for glioma grading: a Meta-analysis

Objective: To systematically review the efficiency of ¹⁸F-FDG PET in glioma grading by using Meta-analysis. Methods: Retrieval in PubMed and China National Knowledge Infrastructure (CNKI) was performed. Relevant papers concerning with glioma diagnoses with ¹⁸F- FDG PET were selected. Paper quality was evaluated according to the standard of diagnostic test recommended by Cochrane Workshop. The data of glioma malignancy degree defined as semi-quantitatively and qualitatively were extracted from the papers. Meta-analysis was conducted with the Meta-Disc software to calculate pooled weighted sensitivity and specificity with 95% confidence interval (CI). Summary receiver operating characteristic (SROC) curve was performed and the areas under the curve (AUC) were calculated. Results: Seven hundred and fifty-three patients from 17 papers (16 in English, 1 in Chinese) were included. Two hundred and seventy-two patients from 11 papers were using semi-quantitative (tumor to cortex ratio, T/C; tumor to white matter ratio, T/W) method and 481 patients from 9 papers were using qualitative method (visual observation, some of the papers had 2 or more methods). After heterogeneity test was done, different effect models were selected. The pooled weighted sensitivity, specificity and diagnostic odds ratio (DOR) with 95% CI for T/C group was 0.952 (95% CI: 0.903-0.980), 0.409 (95% CI: 0.318-0.504) and 11. 746 (95% CI: 5.368-25.702) respectively. The pooled weighted sensitivity, specificity and DOR with 95% CI for T/W group was 0. 857 (95% CI: 0.768-0.922), 0.538 (95% CI: 0.431-0.642) and 22. 066 (95% CI:7.077-68.800) respectively. The pooled weighted sensitivity, specificity and diagnostic odds ratio (DOR) with 95% CI for qualitative method was 0.810 (95% CI: 0.757-0.855), 0.870 (95% CI: 0.819-0.911) and 15.282 (95% CI: 3.716-62.851) respectively. The AUC for T/C group, T/W group and qualitative method was 0.8604, 0.8373 and 0.8724 respectively. Conclusions: Grading glioma by ¹⁸F-FDG PET with semi-quantitative method may provide high diagnostic sensitivity. If qualitative method is used, the diagnostic specificity may be higher. (authors)