RPS 1602 - Functional breast imaging modalities

Author Block: C. Bozzola, L. Crasti, E. Balboni, C. Beretta, L. Nocetti, G. Besutti, A. Toss, G. Ligabue, A. Pecchi; Modena/IT
Purpose: This study aimed to determine whether and which radiomic features from breast dynamic contrast-enhanced (DCE) MRI predict the presence of BRCA1/BRCA2 mutations in patients with triple-negative ductal invasive (TNDI) breast cancer.
Methods or Background: This retrospective study included consecutive patients histologically diagnosed with TNDI breast cancer who underwent breast DCE-MRI in 2010-2021. Baseline DCE-MRIs were retrospectively reviewed; two percentage maps of wash-in and wash-out were computed and breast lesions were manually segmented, drawing a 5 mm-Region of Interest (ROI) inside the tumour and another 5 mm-ROI inside the contralateral normal glandular tissue. Features for each map and each ROI were extracted with the Pyradiomics extension of 3D Slicer and considered first separately (tumour and contralateral gland) and then together. In each analysis, eight more important features for BRCA1/2 status classification were selected with Maximum Relevance Minimum Redundancy algorithm and used to fit four different classifiers.
Results or Findings: The population included 69 patients for a total of 88 lesions (21 in BRCA1-mutated, 2 in BRCA2-mutated, and 65 in non-BRCA-carriers). The best classifier for BRCA mutation was Logistic Regression fitted with both tumour and contralateral gland features, reaching an AUC of 0.78, a sensitivity of 0.9 (95%CI: 0.86-0.94) and a specificity of 0.78 (95%CI: 0.74-0.82). Two features were higher in BRCA-mutated compared to non-BRCA-mutated (correlation from grey level co-occurrence matrix and root mean square), both measured in the contralateral gland in wash-out maps. They represented the coarseness of the pattern inside the ROI and the variability of voxel intensities, respectively.
Conclusion: This study shows the feasibility of a radiomic study with DCE maps of the breast and the potential of radiomics in predicting BRCA mutational status.
Limitations: The limitations of the study were that it was a retrospective design and a limited sample size.
Funding for this study: This research has received funding from the European Union-NextGenerationEUthrough the Italian Ministry of University and Research under PNRR -M4C2-I1.3 Project PE_00000019 "HEAL ITALIA" to Giulia Besutti, E93C22001860006.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the AVEN Ethical Committee.

Author Block: P. Clauser¹, N. Pötsch¹, P. Kapetas¹, M. Hörnig², M. Weber¹, R-I. Milos¹, P. A. Baltzer¹, T. H. Helbich¹; ¹Vienna/AT, ²Forchheim/DE
Purpose: This study aimed to compare the diagnostic performance of a CE-DBT prototype with CEM. Contrast-enhanced mammography (CEM) is increasingly used in clinical practice, but its value is limited by the 2D nature of the examination. Contrast-enhanced tomosynthesis (CE-DBT) allows a quasi-3D evaluation of contrast-enhanced images and could improve lesion characterisation.
Methods or Background: This prospective study was approved by the ethics committee and all patients gave written informed consent. Women presenting with suspicious findings on mammography, DBT or ultrasound were invited to participate in the study. Participants underwent CE-DBT of the breast with suspicious findings using a dedicated prototype in addition to CEM. The suspicious findings were biopsied and only histologically verified lesions were included in the analysis. Four readers (R1 and R2 non-experienced; R3 and R4 experienced) evaluated the images, blinded to patients’ history, previous imaging, and histology. The readers evaluated CEM (including mammography and recombined images) and CE-DBT (including DBT and synthetic mammography) in separate sessions and gave a BI-RADS score for each finding. Sensitivity and specificity were calculated and compared.
Results or Findings: We included 84 patients (mean age 56 years, range 39-70) with 91 histologically verified breast lesions (27 benign, 64 malignant). Sensitivity was comparable between CEM and CE-DBT for non-experienced readers, ranging from 90% to 95%. Sensitivity improved using CE-DBT for both experience readers (from 90% and 87% with CEM to 100% and 94% with CE-DBT). Specificity was lower for non-experienced than for experienced readers with both imaging modalities, with no significant differences between modalities.
Conclusion: Our study showed that CE-DBT allowed an improvement in sensitivity, particularly for experienced readers, with no significant decrease in specificity.
Limitations: This study was a single-centre and cancer-enriched dataset.
Funding for this study: Funding was received from Siemens Healthcare GmBH.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This prospective study was approved by the local ethics committee.

Author Block: D. Pugliese, C. Bernardi, D. Caruso, M. Zerunian, G. Maccagno, R. Gallo, A. Laghi, A. Speranza; Rome/IT
Purpose: This study aimed to investigate whether a reduced dose of iodinated contrast agent, at a higher concentration, maintains adequate image quality compared with a standard dose. Contrast-enhanced spectral mammography (CESM) produces dual-energy subtracted images that demonstrate iodine uptake in infiltrating breast tumours.
Methods or Background: One hundred patients with BI-RADS 6 who underwent CESM study were enrolled: 50 women had received a dose of 1.5 ml/kg of Iomeprole 350mg/ml iodinated contrast agent and 50 women a dose of 1.0 ml/kg Iomeprole 400 mg/ml. Quantitative evaluation of the images was obtained by measuring two ROIs (regions of interest): the first placed on the contrast-enhancing lesion and the second on the background of the image. The percentage difference in signal between the enhancing lesion and the background (%RS) and the signal-to-noise ratio (SNR) was calculated. The qualitative assessment was independently analysed by two experienced radiologists using EUREF criteria.
Results or Findings: The quantitative evaluation showed a slightly higher average lesion-enhancing value in the group with Iomeprole 350 mg/ml vs 400 mg/mI (mean ROI: 2104.95±37.95 vs 2072.89±35.35, P=0.12). The difference between %RS and SNR calculated by the Wilcoxon test showed no statistically significant difference between the two groups (respectively, p-value >0.9 and p-value >0.4). Qualitative assessment scored equally for lesions’ enhancement in both the first and second groups.
Conclusion: Our preliminary results showed that it is possible to obtain comparable image quality in CESM studies by using a reduced dose of high-concentration iodinated contrast agent, compared to the standard dose.
Limitations: This study was a single-centre study with a small sample size.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Written informed consent was acquired for all patients and approved by the Institutional Review Board.

Author Block: C. Wilpert, O. Gebler, T. Stein, F. Bamberg, M. Windfuhr-Blum, C. Neubauer, J. Neubauer; Freiburg im Breisgau/DE
Purpose: The objective of this study was to describe the enhancement, iodine values and contrast of breast cancers, DCIS and benign breast lesions in contrast-enhanced (CE) PC-CT.
Photon-counting CT (PC-CT) has the advantage of high spatial resolution, reduced noise and improved iodine contrast compared to conventional CT. The prone breast positioning is promising for intermodal comparisons.
Methods or Background: A prospective study included 70 women (55 years ±14SD) with biopsy-confirmed breast cancers and breast MRI for lesion comparisons (BI-RADS). A PC-CT (NAEOTOMAlpha, Siemens, Erlangen) of the thorax/abdomen was performed in a prone position with special breast bearing after bolus injection of iodinated contrast-medium (fixed delay: 85 seconds) with multiplanar reconstructions of both breasts (FOV: 34 cm, matrix: 1024 x 1024, slice-thickness: 2 mm) including iodine maps and 65 keV monoenergetic images. A ROI-based analysis of HU-values and spectral information was performed referenced to the ascending aorta for quantification of iodine amount.
Results or Findings: Analysis of 70 biopsy-proven breast cancers, 26 DCIS, six fibroadenoma, eight intramammary lymph nodes and eight cystic lesions. Eight additional cystic lesions could not be detected at all. Mean enhancement, mean iodine concentrations and % of enhancement to the aorta reference were highest in breast cancers (112 HU, 2.7 mg/ml, 52%) and differed significantly from all other lesion types including DCIS (91 HU,1.7 mg/ml, 33%), fibroadenoma (61 HU, 0.3 mg/ml, 5%), intramammary lymph nodes (79 HU,1.8 mg/ml, 38%) and cystic lesions (33 HU, 0 mg/ml, -1%); each p<0.001. The contrast was highest in breast cancers. Cystic lesions presented with low contrast.
Conclusion: Compared to all other types of lesions, breast cancers displayed the highest enhancement and iodine concentrations; these characteristics indicate that breast CT reconstruction might be suited for pre-therapeutic local breast cancer staging. Additionally, DCIS can be discriminated against with CE PC-CT. In contrast, cystic lesions cannot be displayed efficiently.
Limitations: Only a small number of biopsy-proven benign lesions were analysed. Morphologic features were not compared to MRI. PC-CT is not sufficient for the presentation of micro-calcifications.
Funding for this study: This study was partially funded by the Young Researchers Grant awarded by the EUSOBI.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Ethics Number: 21-1717, German clinical trials register: DRKS00028997

Author Block: C. Wilpert, M. Molina, T. Stein, F. Bamberg, M. Windfuhr-Blum, C. Neubauer, J. Neubauer; Freiburg im Breisgau/DE
Purpose: The objective of this study was to investigate whether lymph node metastases can be distinguished from benign lymph nodes and breast cancers by their enhancement in contrast-enhanced (CE) PC-CT. Imaging of axillary lymph nodes continues to be a challenge, where up to this date sonography remains the imaging reference. Photon-counting computed tomography (PC-CT) allows for high spatial resolution and iodine quantification.
Methods or Background: Inclusion of 75 women (56 years ±14 SD) with biopsy-confirmed breast cancers and MRI available to confirm diagnostic criteria of benign lymph nodes (BI-RADS). A PC-CT (thorax/abdomen) was performed with special prone breast positioning (NAEOTOMAlpha, Siemens, Erlangen) after bolus injection of iodinated contrast medium (delay: 85 seconds) and multiplanar reconstructions of both breasts (FOV: 34 cm, matrix: 1024 x 1024, slice-thickness: 2 mm) including iodine maps and 65 keV monoenergetic images. ROI-based analysis was performed using the iodine concentration of the aorta ascendens as a reference.
Results or Findings: Analysis of 70 biopsy-proven breast cancers, 18 lymph node metastasis and 57 benign lymph nodes. Enhancement was 121 HU in metastasis, 112 HU in breast cancers and 105 HU in benign lymph nodes. Iodine concentrations and referenced enhancement (%) was highest in breast cancers (2.7 mg/ml, 52%). Lymphnode metastasis differed significantly from benign lymph nodes (2.5 mg/ml, 49% versus 1.9 mg/ml, 37%; enhancement: p=0.004; iodine: p=0.008) but not from breast cancers (enhancement: p=0.251; iodine: p=0.153). In contrast, benign lymph nodes differed significantly from breast cancers (p <0.001).
Conclusion: Enhancement of lymph node metastasis was similar to breast cancers and differing from benign lymph nodes, which might allow further differentiation. However, as ranges were rather wide we do not believe cut-off values can be drawn from the data for lymph node evaluation with PC-CT; instead, as known from MRI, ultrasound with it’s ability to depict morphology and perfusion is expected to outperform PC-CT providing less morphologic information.
Limitations: Morphologic features of lymph nodes were not evaluated. PC-CT was not compared to other imaging modalities.
Funding for this study: This research was partially funded by the Young Researchers Grant awarded by the European Society of Breast Imaging (EUSOBI).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Ethics Number: 21-1717, German clinical trials register: DRKS00028997

Author Block: Y. Hu, M. LI, N. Shao, Z. Xiaoling; Guangzhou/CN
Purpose: This study aimed to quantitatively assess the differences in parameters of dynamic contrast-enhanced MRI (DCE-MRI) in HER2-zero, HER2-low, or HER2-positive tumours, and to build optimal models for early prediction of HER2-low breast cancer (BC).
Methods or Background: Clinical and DCE-MRI data from 220 BC patients receiving neoadjuvant chemotherapy (NACT) were retrospectively analysed. Quantitative and semi-quantitative DCE-MRI parameters were compared in the HER2-zero, HER2-low, or HER2-positive groups before and after early NACT. Empirical models were developed to predict HER2-low BC using logistic regression analysis and receiver operating characteristic (ROC) analysis.
Results or Findings: Patients of HER2: low BC have a lower pCR rate compared with HER2-zero and HER2-positive (17.9% vs. 10.4% vs. 29.5%, p<0.001), predominantly in the HR (hormone receptor) negative group (22.2% vs. 7.7% vs. 40.5%, p<0.001). Before NACT, HER2-low BC exhibited higher Kep, Ktrans, Washin, and lower TME intratumoral perfusion characteristics, and higher Kep and lower TME in peritumoral than the other group. Notably, after early NACT, changes in Ktrans, Kep, and Washin in intratumoral and peritumoral perfusion were more pronounced in the HER2-low group compared to other groups. The ROC curves (AUC) for the pre-NACT intratumoral, peritumoral, and combined perfusion models were 0.675 (95% CI: 0.600-0.750), 0.661 (95% CI: 0.585-0.738), 0.731 (95% CI: 0.660-0.802). The combined pre-and-post-NACT perfusion model further improved predictive performance accordingly, with AUCs of 0.764 (95% CI: 0.637-0.865), 0.795 (95% CI: 0.711-0.878), 0.850 (95% CI: 0.774-0.926).
Conclusion: The study revealed perfusion heterogeneity between different HER2 statuses and identified the best imaging model as a non-invasive tool to predict HER2-low BC, which can help pre-treatment clinical decision-making.
Limitations: Further multi-centre validation is required.
Funding for this study: This study has received funding from the Beijing Science and Technology Innovation Medical Development Foundation (KC2021-JX-0044-2).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Ethics Committee of the First Affiliated Hospital of Sun Yat-Sen University (No.2020-536).

Author Block: M. Lenaerts¹, L. Van der Voort¹, M. Smidt¹, C. Van De Weijer¹, V. Tjan-Heijnen¹, F. A. Gallagher², L. Aloj², T. van Nijnatten¹; ¹Maastricht/NL, ²Cambridge/UK
Purpose: This study aimed to assess the proportion of ER-positive tumours with suboptimal 18F-FDG uptake. The extent of breast cancer is an important prognostic factor in locally advanced breast cancer (LABC). Therefore, staging using 18F-FDG PET/CT is recommended. However, previous studies have confirmed a significantly lower degree of 18F-FDG uptake in primary breast tumours of the oestrogen receptor (ER)-positive subtype compared to other subtypes. Consequently, suboptimal 18F-FDG uptake in ER+ LABC might lead to suboptimal staging.
Methods or Background: Baseline 18F-FDG PET/CT scans of female patients diagnosed with ER+ LABC in the Maastricht University Medical Centre between 2011-2022 were retrospectively collected. The maximum standardised uptake value (SUVmax) of the primary tumour was measured. Different SUVmax cut-off values were applied to determine the proportion of suboptimal 18F-FDG PET/CT exams. Multivariable logistic regression was performed to determine the possible correlation between clinicopathological predictors and the SUVmax of the primary tumour.
Results or Findings: 74 patients were included. SUVmax cut-off values of 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 correspond with a proportion of women with a primary tumour SUVmax below the cut-off value of 6.8%, 16.2%, 24.3%, 31.1%, 39.2%, 40.5%, 45.9%, respectively. When considering 3.0 as an arbitrary cut-off value for SUVmax of the primary tumour, multivariable logistic regression of both ER-percentage (10-100%) and tumour grade (1-2 vs. 3) showed a lower tumour grade to be significantly correlated with a lower SUVmax (0.07 [0.008–0.562]; p=0.013).
Conclusion: A considerable proportion of ER+ LABC patients have a relatively low SUVmax value of the primary tumour, indicating a potential suboptimal staging on the baseline 18F-FDG PET/CT exam. When considering SUVmax 3.0 as an arbitrary cut-off value of the primary tumour, 24.3% of the patients might have a suboptimal baseline 18F-FDG PET/CT exam.
Limitations: No limitations were identified.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Due to the retrospective design of the study, approval was waived by the local ethics committee

Author Block: D. Pupo¹, L. Nicosia², A. C. Bozzini², L. Mariano³, G. Signorelli², F. Abbate², F. Priolo², E. Cassano²; ¹Naples/IT, ²Milan/IT, ³Turin/IT
Purpose: This study aimed to evaluate the diagnostic performance and relationship with the receptor profile of this new descriptor. The new version of the Breast Imaging Reporting And Data System (BIRADS) related to contrast-enhanced mammography (CEM) encourages investigations on a new enhancement descriptor: "Lesion Conspicuity" (LC): defined as the intensity of enhancement of a lesion in relation to the background parenchymal enhancement (BPE).
Methods or Background: 325 patients with 381 breast lesions undergoing CEM before histological evaluation were selected. Four radiologists, in a blind study, classified LC into the following levels: absent, low, moderate and high. Considering "moderate" and "high" as predictive of malignancy, the diagnostic performance of CEM was calculated using histological biopsy results as the gold standard. The association between LC values and receptor profile of neoplasms was also evaluated.
Results or Findings: The mean age at CEM examination was 50 years (range: 45-59). Considering the LC value of the most experienced radiologist in Low Energy (LE) image interpretation, we obtained a sensitivity (SE) of 91.9% (95% CI: 88.6%-95.2%) and specificity (SP) of 67.2% (95% CI: 58.9%-75.5%). An association was observed between "high" lesion conspicuity with unexpressed ER/PgR (p=0.025), with Ki-67 > 20% (p=0.033) and with G3 grading (p=0.020).
Conclusion: The new descriptor, "Lesion Conspicuity," demonstrated more than satisfactory performance in predicting lesion malignancy and significant correlation with the receptor profile of malignant breast neoplasms.
Limitations: This was a monocentric study.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The retrospective study was approved by The Institutional Review Board.