Table 4 Characteristics of studies with qualitative analysis of BPE levels
Study ID | BPE classification | Comparison Parameters | MRI sequence used | MRI follow-up time points | No. of readers | Blindness to clinical data | Inter- and intra-reader variability | Findings |
|---|---|---|---|---|---|---|---|---|
Preibsch et al. 2016 [16] | Minimal (1), mild (2), moderate (3) and marked enhancement (4) | The baseline BPE; The change in BPE | Subtraction images | Before and after NAC | 2 | Aware that patients received NAC for breast cancer but blinded to results from another reader | Substantial (κ_right breast = 0.73, κ_left breast = 0.77) before NAC and moderate (κ_right = 0.43, κ_left = 0.60) after NAC; The change in BPE was moderate (κ_right = 0.62, κ_left = 0.60) | The decrease in BPE was significantly higher in the cases with CR than in those with PD (P = 0.02) |
Dong et al. 2018 [20] | Minimal (1), mild (2), moderate (3) and marked enhancement (4) | BPE levels before and after NAC; The change in BPE | All images | Before and after NAC | 2 | Blinded to the patients’ information | κ = 0.773 at baseline; κ = 0.706 after NAC | The decrease in the BPE level was more dramatic in the pCR group than in the non-pCR group in the patients with HER2-positive breast cancer |
You et al. 2018 [21] | Minimal (1), mild (2), moderate (3) and marked enhancement (4) | BPE levels before and in the 2nd NAC; The change in BPE | The early post-contrast images | Before and the 2ed cycle of NAC | 2 | NR | κ = 0.701 at baseline and κ = 0.784 after the 2nd NAC cycle | Decreased BPE after the 2nd NAC cycle was significantly associated with pCR |
Choi et al. 2015 [22] | Minimal (1), mild (2), moderate (3) and marked enhancement (4) | BPE levels before and after NAC | Early post-contrast fat-suppressed T1W images or subtraction images | Before and after NAC | 2 | Retrospective analysis in a blinded manner without patient pathology data | NR | Minimal BPE was the most prominent after NAC, showing a similar rate between the pathologic responder group and the non-responder group |
Oh et al. 2018 [24] | Minimal (1), mild (2), moderate (3) and marked enhancement (4) | BPE levels before and after NAC; The change in BPE | The first post-contrast sequences and maximum-intensity-projection images | Before and after NAC | 2 | NR | NR | Post-NAC BPE was lower in the pCR group than in the non-pCR group (p = 0.0004); Changes in BPE after NAC were significantly greater in the pCR group than in the non-pCR group |
La Forgia et al. 2021 [25] | Minimal (1), mild (2), moderate (3) and marked enhancement (4) | BPE levels before and after NAC; BPE levels in intermediate; The change in BPE | The first post-contrast sequence | Before and after at least 3 months of NAC; After the NAC | 3 | NR | A good level of agreement with a Cohen’s kappa value of about 0.55 for each comparison | The response to therapy was found to be significantly associated with BPE reduction |
Teixeira et al. 2018 [18] | Minimal, mild, moderate and marked enhancement | BPE levels before and after NAC; The change in BPE | The first contrast-enhanced image | Before and after the NAC | 1 | Blinded to all previous analyses | NR | A pre-NAC reduction in BPE, in the affected or contralateral breast, was an independent predictor of achieving a pCR |
Moliere et al. 2019 [26] | Minimal (1), mild (2), moderate (3) and marked enhancement (4) | BPE levels before and after NAC | Subtracted enhanced series | Before and after NAC | 2 | Blinded to pathology data | Fair agreement between readers: κ = 0.44 for pre-therapeutic imaging and κ = 0.41 for post-therapeutic imaging; Fair to good intra-rater reliability (κ = 0.64 for pre-therapeutic imaging, κ = 0.50 for post-therapeutic imaging) | There was no significant difference between CR and non-CR in term of pre- and post-therapeutic BPE |