Twenty-five studies (n=789, range seven to 166) were included (16 were retrospective studies). Twenty-one studies were classed as high quality and four were of acceptable quality.
In the 17 studies (n=571) that used FDG-PET, pooled sensitivity was 0.84 (95% CI 0.79 to 0.87, I2=65%) and pooled specificity was 0.84 (95% CI 0.79 to 0.89, I2=69%). Positive likelihood ratio was 3.35 (95% CI 1.67 to 6.73). Negative likelihood ratio was 0.24 (95% CI 0.15 to 0.38). The area under the summary ROC curve was 0.89. Six studies included lesion-based data (n=237 lesions). Pooled (lesion-based) sensitivity was 0.92 (95% CI 0.86 to 0.95) and pooled specificity was 0.78 (95% CI 0.66 to 0.87) for specificity. In patients who presented with elevated serum thyroglobulin and negative 131I scan (eight studies, n=217) pooled sensitivity was 0.89 (95% CI 0.83 to 0.93) and pooled specificity was 0.85 (95% CI 0.72 to 0.93). The area under the SROC curve was 0.93.
In the six studies (n=165) that used FDG-PET/CT, pooled sensitivity was 0.94 (95% CI 0.87 to 0.97, I2=15%) and pooled sensitivity was 0.84 (95% CI 0.72 to 0.92, I2=59%), specificity. Positive likelihood ratio was 4.33 (95% CI 1.83 to 10.21) and negative likelihood ratio 0.1 (95% CI 0.04 to 0.23). The area under the SROC curve was 0.97.