The review included 32 prospective studies. The authors did not report the total number of participants, but it appeared that at least 1,108 people were included in the analyses.
Initial diagnosis.
Thirteen studies (n=606) assessed the diagnostic performance of FDG PET prior to breast biopsy. Sensitivity estimates ranged from 79 to 100% and specificity estimates from 50 to 100%. The pooled estimates of sensitivity and specificity were 88% (95% confidence interval, CI: 83, 92) and 79% (95% CI: 71, 85), respectively. Average performance on the summary ROC curve was 89% sensitivity and 80% specificity.
The authors found limited evidence to assess the diagnostic performance of FDG PET in people with small non-palpable lesions, abnormal mammograms, palpable masses but indeterminate mammograms, and populations with a disease prevalence lower than 50%. They found that among populations with higher disease prevalence, the risk of false negatives may be too high relative to the benefits of avoiding biopsy for a benign lesion.
The authors identified no studies in people referred for short interval mammographic follow-up due to low suspicion mammogram findings.
Staging axillary lymph nodes.
Four studies (n=203) reported on the staging of axillary lymph node metastases in people with non-palpable axillary lymph nodes. The pooled sensitivity estimate for FDG PET was 80% (95% CI: 46, 95) and the pooled specificity estimate was 89% (95% CI: 83, 94).
Loco regional recurrence or distance metastases or recurrence.
Two studies (n=85) focused on detecting loco regional recurrence. The authors stated that there was insufficient evidence to draw conclusions about the effects of FDG PET in this context.
The review included 2 studies (n=109) on the detection of distant recurrence or metastases to bone (one of the studies also looked at loco regional recurrence as outlined above) and 3 studies on recurrence or metastases in sites other than bone, all with fewer than 10 participants with metastases. The authors concluded that there was insufficient information to draw conclusions about using FDG PET for detecting recurrence or metastases in bone, lung, liver, or other distant sites.
Evaluating response to treatment. The authors identified 4 studies (n=103) on whether the use of FDG PET early during treatment predicted treatment response. They concluded that there was insufficient high-quality information on this topic.