*2.4. Statistical Analysis*

A proportion meta-analysis was carried out using a random- effects statistical model. Pooled data are presented with their 95% confidence interval (95% CI) values. Heterogeneity across studies was assessed with the I-square statistic (I2): a value of 50% or higher was considered as a high heterogeneity. Publication bias was evaluated with Egger's test [16].

The multidisciplinary follow-up was used as SOR to be able to compute the sensitivity of both image modalities (PBA/LBA). The OpenMeta[Analyst] statistical software (CEBM, Providence, RI, USA) was used for the statistical analyses.

### **3. Results**

#### *3.1. Literature Search Outcome*

A total of 55 records were initially identified after duplicate removal, and their titles and abstracts were assessed; 12 articles had to be excluded since they reported single cases or small cases series. Out of the remaining 43 records, 36 were excluded because they did not meet the set inclusion criteria. Therefore, seven articles were finally selected [12,17–22], including 171 ER+ BC patients (Figure 1).

**Figure 1.** PRISMA flowchart, depicting the studies selection criteria.
