RPS 502 - MRI and contrast-enhanced mammography for treatment planning

Author Block: D. A. Resch, O. Lafcı, P. Clauser, Z. Bago-Horvath, Y. Tan, G. Langs, T. Helbich; Vienna/AT
Purpose: To analyze the significance of radiomic shape features derived from dynamic contrast-enhanced (DCE) breast MRI in assessing early treatment response in breast cancer patients undergoing neoadjuvant chemotherapy (NAC).
Methods or Background: We report on the first 29 breast cancer patients of a prospective study, who underwent NAC and received multiparametric 18F-FDG PET/MRI imaging at baseline (T0) and after three weeks of NAC (T1). DCE-MRI derived radiomic shape features, including SHAPE_Volume (mL), SHAPE_Volume (vx), SHAPE_Sphericity, SHAPE_Surface(mm²) and SHAPE_Compacity were extracted using LIFEx. The agnostic shape features were compared to the treatment response assessment by two radiologists. All data were stratified by the pathological complete response status (pCR or non-pCR). Mean change (Δ) of all investigated features were calculated. Pearson Chi-Square Test, T-Test and Mann-Whitney U Test were applied.
Results or Findings: Twelve out of 29 (41%) patients had pCR and 17/29 (59%) had non-pCR.
Radiomic shape features, including ΔSHAPE_Compacity and SHAPE_Volume at T1, were significantly associated with pCR (P = 0.015 and P = 0.04, respectively).
Radiologist's response assessment (stable disease, partial response, disease progression) was not significantly associated with pathological outcomes (pCR vs. non-pCR) (Pearson Chi-Square: χ2=3.727χ2=3.727, P = 0.155). Similarly, the likelihood ratio test did not show significant results (P = 0.105).
Conclusion: While the radiologist’s assessment did not significantly correlate with pathological outcomes, radiomic shape features, particularly ΔSHAPE_Compacity and SHAPE_Volume, demonstrated significant associtations with pCR.
These findings suggest that DCE derived radiomic shape features might be a promising tool for prediction of early NAC response in breast cancer patients and may challenge the validity of RECIST criteria at this stage.
Limitations: This study is limited by the small sample size. We will be able to report on more data in March 2025.
Funding for this study: This study is supported by the WWTF (Vienna Science and Technology Fund), grant number LS20-065.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: EK Nr. 510/2009

Author Block: X. Ma, Q. Xiao, Y. Huang, Y. Gu; Shanghai/CN
Purpose: To describe the Reactive cutaneous capillary endothelial proliferation (RCCEP) that occurs within the breast tissue of triple-negative breast cancer (TNBC) patients undergoing neoadjuvant chemoimmunotherapy with camrelizumab and to investigate the potential factors influencing its occurrence.
Methods or Background: We retrospectively collected 106 cases of TNBC patients from March 2021 to August 2023, including 60 cases who received neoadjuvant chemotherapy (NAC) and 46 cases who underwent neoadjuvant chemoimmunotherapy (NACI). We analyzed the clinical data, pathological characteristics, MRI at baseline and during each treatment cycle for all patients, then identified abnormal lesions after treatment and explored their influencing factors.
Results or Findings: Abnormal enhancement was observed in 30 patients (3 NAC vs. 27 NACI, P<0.001). In the NACI group, cases of abnormal enhancement included 3 cases of ring enhancement, 2 cases of linear enhancement, and 22 cases of mass enhancement, which typically appeared after the second cycle and rarely appeared after the fourth or sixth cycle. These lesions generally decreased in size with continued treatment. In the NACI group, the development of new enhancement lesions was correlated with younger age (P=0.007), premenopausal status (P=0.014), a lack of peritumoral edema on baseline MRI (P=0.007), and the presence of mass enhancements (P=0.012).
Conclusion: TNBC patients treated with camrelizumab frequently exhibit RCCEP in the breast tissue, primarily presenting as mass enhancements on MRI. These lesions often regress in size even without drug withdrawal, suggesting that recognizing this pattern can prevent unnecessary biopsies and help in adjusting treatment strategies accordingly.
Limitations: First, this study is retrospective and includes a small sample size; second, in future studies, it is necessary to extend the research period to explore the relationship between RCCEP in the breast and their prognosis.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Fudan University Shanghai Cancer Center

Author Block: N. Caldarelli, G. Della Pepa, G. Irmici, E. D'Ascoli, C. De Berardinis, D. Ballerini, A. Bonanomi, C. Depretto, G. P. Scaperrotta; Milan/IT
Purpose: The study evaluated patient preferences between contrast-enhanced MRI (MRI) and contrast-enhanced mammography (CEM) for breast cancer imaging. MRI has long been the gold standard for breast cancer staging and monitoring neoadjuvant chemotherapy, while CEM has gained popularity due to its lower cost, faster examination times, and accessibility, offering comparable diagnostic performance.
Methods or Background: The aim of this study was to understand patient preferences between these two modalities to support the broader implementation of CEM in clinical practice. The study included 152 patients who underwent both procedures within a six-month interval between 2018 and 2024. A Likert scale questionnaire was used to assess patient preferences focusing on three main aspects: breast positioning (compression for CEM and coil positioning for MRI), sensation during contrast injection, and overall comfort (exam duration, machine noise, and environmental factors).
Results or Findings: Results showed that 72.4% of patients preferred CEM, 26.3% preferred MRI, and 1.3% expressed no preference. CEM was significantly more comfortable (p<0.001), with higher median scores than MRI. The main reasons for preferring CEM included faster exam time (28%), lack of claustrophobia (17%), and absence of noise (15%). In terms of breast positioning, there was a slight preference for MRI (p=0.04). No significant differences were found in the sensation during contrast injection (p=0.07).
Conclusion: In conclusion, CEM was the preferred option for most patients, indicating its potential as an alternative to MRI in clinical settings. These findings support further exploration of CEM's role in breast cancer imaging.
Limitations: none. We have no limitations.
Funding for this study: none. We don't need any funding for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: none. We don't have any Ethics committee.

Author Block: D. Prinz¹, S. J. Bartsch¹, J. Friske¹, D. Laimer-Gruber¹, T. H. Helbich¹, K. Pinker-Domenig²; ¹Vienna/AT, ²New York, NY/US
Purpose: Tumor acidosis is a key hallmark of breast cancer (BC). The increased glucose consumption triggers aerobic glycolysis, leading to the production of lactic acid which results in therapy resistance.
Currently, there is no non-invasive tool available to image tumor pH in vivo.
We attempted to image the extracellular pH (pHe) with acidoCEST using Iopamidol, and the intracellular pH (pHi) using the CEST-derived AACID (amine and amide concentration-independent detection) metric.
Non-invasive imaging of tumor pH is of great interest because pH is one of the first biomarkers which changes during treatment.
Methods or Background: Female athymic nude mice were inoculated with BC cells of HER2+ (SKBR-3, n = 5) and triple-negative (MDA-MB-231, n = 4) molecular subtypes. MRI imaging was performed using a preclinical 9.4T MRI system. CEST images were acquired and ratiometric measurements were evaluated for the endogenous AACID from baseline images and the acidoCEST signal based on post-challenge images.
Results or Findings: Both acidoCEST and AACID produced reliable and stable signals. The lower pHe and the higher pHi could be visualized for HER2+ and triple-negative BC subtypes. Parametric maps of AACID and acidoCEST revealed differences in the pH gradients between BC subtypes, which correlated with tumor aggressiveness.
Conclusion: We conclude that the AACID-based measurement of pHi sufficiently quantifies the pH gradient between extracellular and intracellular compartments and may become a promising non-invasive contrast-free imaging method to monitor early treatment response in BC.
Limitations: Due to the preclinical nature of this study, the small number of mice used presents a limitation.
Funding for this study: This work was funded by the Vienna Science and Technology Fund (WWTF), grant no. LS19-018.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This animal study was approved by Austrian Federal Ministry of Education, Science and Research [66.009/0284-WF/V/3b/2017; 2020-0.363.124; 2022-0.726.820] and the Intramural Committee for Animal Experimentation of the Medical University of Vienna.

Author Block: C. De Berardinis¹, C. Depretto¹, G. Della Pepa¹, E. D'Ascoli¹, G. Irmici¹, E. Ancona¹, R. Spiaggia², L. Corradini², G. P. Scaperrotta¹; ¹Milan/IT, ²Mussomeli/IT
Purpose: To assess the correlation between the degree of background parenchymal enhancement (BPE) on contrast-enhanced mammography (CEM) and breast density, menopausal state, receptor status, HER 2 expression and proliferation index (Ki-67) of malignant tumors.
Methods or Background: We retrospectively evaluated all patients who underwent CEM at our Institution from January 2023 to April 2024 for pre-operative staging and problem solving. BPE was classified as minimal, mild, moderate, or marked, in accordance with the BIRADS lexicon. We assessed the menopausal status and evaluated the receptor status and Ki-67 of each malignant lesion. Statistical analysis was performed using the Spearman’s test to evaluate the correlation between density and BPE. Chi-square test was used to evaluate the correlation between BPE, menopausal status, receptor status, and Ki-67.
Results or Findings: A total of 194 patients were included. Spearman's test analysis demonstrated a weak correlation between BPE and breast density (ρ=0.353, p<0.001, CI:0.219-0.469). The Chi-Square test revealed a strong association between BPE and menopausal state, with lower BPE levels in postmenopausal patients compared to premenopausal patients (X²=30.846, p<0.001). There was no statistically significant association between BPE and receptor status (X²=14.494, p=0.270) and HER2+ status (X²=1.648, p=0.649). There was suggestive but not statistically significant association (X²=6.738, p=0.081) between BPE and Ki67.
Conclusion: A significant correlation was demonstrated between the level of BPE on CEM and menopausal status. Instead, the correlation with breast density proved to be weak, while no statistically significant correlation was found with tumor receptor status. BPE also appears to have a suggestive correlation with Ki-67% and consequently with tumor aggressiveness.
Limitations: This association needs more data and larger sample size to be confirmed but suggests how BPE might be related to breast cancer risk.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: None

Author Block: G. Vatteroni¹, N. Pötsch², P. Clauser², P. A. Baltzer²; ¹Milan/IT, ²Vienna/AT
Purpose: This systematic review and meta-analysis investigates the added value of Contrast Enhanced Breast MRI (CE-MRI) to rule out malignancy in patients with lesions of uncertain malignant potential (B3) diagnosed at image guided biopsy.
Methods or Background: A systematic review and meta-analysis were conducted using predefined criteria. Eligible articles, published in English until August 2024, dealt with CE-MRI in the context of B3 lesions. Two reviewers extracted study characteristics, including true positives (TP), false positives (FP), true negatives (TN), and false negatives (FN). Sensitivity, specificity, negative likelihood ratio, and positive likelihood ratio were calculated using bivariate random effects. Fagan nomograms identified the maximum pretest probability at which post-test probabilities of a negative MRI aligned with the 2% malignancy rate benchmark for downgrading BI-RADS 4 to BI-RADS 3. I² statistics and meta-regression explored sources of heterogeneity. P-values <0.05 were considered significant.
Results or Findings: Seven studies investigating 479 patients with 493 high risk lesions undergoing CE-MRI were included. The average breast cancer prevalence was 17% (88/493). Pooled sensitivity was 91.3% (95%-CI: 82.8%-95.8%) and pooled specificity was 68.8% (95%-CI 50.3%-82.8%) using a random effects model. Overall, CE-MRI missed only 6/493 lesions, all small low-grade Ductal Carcinoma in Situ. Fagan nomograms showed that CE-MRI could rule out malignancy in B3 lesions diagnosed at image guided biopsy up to a pre-test probability of 13.1%.
Conclusion: CE-MRI in the assessment of B3 lesions could potentially identify patients who might avoid surgery, saving costs and time as well as reducing patient anxiety and morbidity. Breast cancer can be ruled out up to pre-test probabilities of 13.1%.
Limitations: n/a
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable

Author Block: J. Lipin Margaret, T. Friehmann, S. Tamir, G. Bachar, A. Grubstein; Petach Tikva/IL
Purpose: In contrast-enhanced imaging for the precise evaluation of Invasive lobular carcinoma (ILC), the aim was to further validate the use of CEM for evaluation of extent of disease in ILC cases, with Digital breast tomosynthesis (DBT) as an adjunct.
Methods or Background: A retrospective study was conducted in a tertiary medical center. All CEM examinations of ILC patients between 2017–2023 were re-read by two breast radiologists. The longest lesion diameter was correlated to pathology findings. For each case, readers provided commentary on the added value of DBT.
Results or Findings: Twenty-four CEM examinations were evaluated. The cohort were on average older than expected for ILC patients (74 vs. 63 years) and were unable to undergo MRI due to advanced age and comorbidities. Enhancing lesions, ranging from 4–75 mm, strongly correlated to pathology results, with statistical significance, for mass and non-mass lesions (r = 0.94, p < 0.001 and r = 0.99, p = 0.002, respectively). For most lesions (17/24, 71%), readers remarked that DBT allowed for improved characterization of lesion margins.
Conclusion: When compared to the pathology findings, ILC was accurately diagnosed and assessed using CEM. The addition of DBT was reported by the interpreting radiologists as a valuable adjunct for margin analysis.
Limitations: Sample size was small, a general issue among studies of ILC in CEM (e.g., 30 subjects in the study by Patel et al. in 2018, 31 in Amato et al. in 2019, and 38 in Costantini M et al. in 2022). The design was retrospective, and furthermore, since all patients underwent CEM due to contraindication to MR, introducing selection bias. No patient had extremely dense breasts or marked enhancement, conclusions regarding the accuracy of CEM in the most challenging breast types cannot be reached.
Funding for this study: None.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Helsinki approval

Author Block: P. Minichetti, M. Lorenzon, S. Sanità, L. Nardone, L. Cereser, R. Girometti, C. Zuiani; Udine/IT
Purpose: To compare Additional Malignant Lesions (AML) detection of CEM or MRI (Breast Contrast-Imaging – BCI) performed for preoperative loco-regional staging of Breast Cancer (BC) in patients with Dense Breast (DB) or Non-DB (N-DB).
Methods or Background: We retrospectively included 290 patients (median age 62 years) with a biopsy-proven BC who underwent CEM (n=129) or 1.5T-MRI (n=161) at our Institute between January 2022 and December 2023. Staging was performed based on EUSOMA criteria or clinical requests. A radiology resident (with >3 years of experience in breast imaging) reviewed all reports written by one-of-four breast radiologists (with 5-25 years of experience). Extracted data included: density according to BI-RADS (C, D classified as DB; A, B as N-DB), background parenchymal enhancement, features of index lesions and AML (not identified before BCI, pathologically proven). The BCI detection rate of AML in DB and N-DB groups was assessed and compared using T-test. P-values<0.05 were considered statistically significant.
Results or Findings: In 201 DB patients, preoperative BCI detected 40 AML (19.9%). In 89 N-DB patients, BCI detected 10 AML (8.9%). The difference in the BCI AML detection rate between DB and N-DB groups was 11% (p=0.0202). In the DB group, the AML detection rate was found to be more than double that in the N-DB group. Specifically, among 71 DB patients, CEM detected 15 AML (21.1%) vs 6 AML in 58 N-DB patients (10.3%); among 130 DB patients, MRI detected 25 AML (19.2%) vs 4 AML in 31 N-DB patients (12.9%).
Conclusion: The usefulness of BCI performed for loco-regional staging is significantly higher in DB than in N-DB patients. The detection rate of AML is comparable between MRI and CEM in DB and N-DB patients.
Limitations: Small cohort, monocentric.
Funding for this study: Nothing.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Institutional Review Board (IRB-DMED)