RPS 1016 - Breast and gynecologic advanced imaging and radiomics

Purpose:

In 2017, the American Joint Committee on Cancer (AJCC) updated the Cancer Staging Manual to the 8^th edition, including a definition of a prognostic staging that incorporates TNM classification and tumour biomarkers. The purpose of this study is to compare the staging of screen-detected breast cancers using the 7^th and 8^th AJCC Cancer Staging Manual editions.

Methods and materials:

The characteristics of 423 breast cancers detected in a screening programme from 2013-2016 were retrospectively reviewed. For each cancer, the anatomical stage based on the 7^th TNM edition and the prognostic stage based on the 8^th edition were calculated and differences analysed.

Results:

The median age at diagnosis was 61 years (range 50-75 years). The anatomical stage was 0 in 13.9% of cases, IA in 63.1%, IB in 6.1%, IIA in 9.9%, IIB in 5.2%, IIIA in 0.7%, and IV in 0.9%, respectively. The application of TNM 8^th edition changed the stage group in 18.2% of women with an upstage in 4.8% and a downstage in 13.2%. Among the upstaged group, 23.8% of cancers were luminal-A, 23.8% luminal-B, and 52.4% triple-negative. 4.8% were grade 1, 38.1% grade 2, and 57.1% grade 3. Among the downstaged group, 76.8% of women were luminal-A and 23.2% luminal-B. 23.2% were grade 1, 69.6% grade 2, and 7.1% grade 3. Major staging changes were observed in stage IA (3.3%), IIA (8.7%), and IIB (3.3%).

Conclusion:

The adjunct of biomarkers to anatomical characteristics (TNM) can change the staging of breast cancers found in a screening programme, resulting most often in a downstage. The application of prognostic staging is important to better define the prognosis and the therapeutic approach, which should be oriented by cancer subtypes.

Limitations:

The cancers that were screen-detected rarely include advanced stages.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To estimate the diagnostic performance of multiparametric breast MRI in the pretreatment identification of non-responders to neoadjuvant chemotherapy (NAC).

Methods and materials:

85 patients (median 44y) with locally advanced invasive breast carcinoma were enrolled in this retrospective study. All underwent a core-cut biopsy with histopathological analysis of ER, HER2, and Ki67. Baseline breast MRI was performed before NAC with an evaluation of T2, ADC coefficient, enhancement pattern, and necrosis. Based on these parameters, patients were designated as responders or non-responders. Levels of response to NAC were based on postoperative histology results: pathological complete response (pCR) as responding, pathological residual disease (pRD) as non-responding. An MRI‐based predictive model supplemented by selected histopathological characteristics of breast carcinoma was constructed using logistic regression analysis. Agreement analysis and diagnostic performance measures (Cohen's kappa, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV)) were calculated. The AUC curve served as an overall measure of discriminative performance.

Results:

Non-responders on initial MRI were non.significantly associated with 1.2 times higher odds for having pRD after NAC in comparison with responders. None of individual MRI features were significantly associated with pRD. Combining an MRI response prediction with histopathological characteristics significantly improved the model performance (for cut-off probability=0.5, sensitivity 89.1%, specificity 36.7%, correct classifications 70.6%, and AUC=72.4% (model deviance Chi-square test: p=0.044; ER+: OR=3.15, 95% CI 1.09-9.15, p=0.035), HER 2 (HER2 negat: OR=3.15, 95% CI 1.02–9.69, p=0.046), ki67 (ki67>30%: OR=2.26, p=0.125)).

Conclusion:

Pretreatment identification of non-responders to NAC is crucial for the further complex management of patients with breast cancer. Multiparametric MRI supported by histopathological parameters of tumours is sufficiently predictive of non-responders to NAC.

Limitations:

n/a

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

To investigate fat-corrected, relaxation-compensated amide proton transfer (APT) CEST MRI at 7 Tesla (7T) in patients with newly-diagnosed breast cancer.

Methods and materials:

10 patients with newly-diagnosed breast cancer and 7 healthy volunteers were included. APT CEST MRI was performed on a 7T whole-body scanner. APT signal intensities were quantified using a multi-Lorentzian fit analysis in the tumour area and in healthy fibroglandular breast tissue after correction of B₀/B₁-field inhomogeneities, fat signal contribution, and T₁- and T₂ -relaxation. Signal intensity differences between normal-appearing and tumour breast tissue were compared using the Mann–Whitney U test. Furthermore, Pearson's correlation analysis between tumour APT signal intensities and the Ki-67 proliferation index was performed.

Results:

APT signals in breast cancer tissue (6.70±1.38%Hz) were significantly increased compared to normal-appearing fibroglandular breast tissue (p=0.001). Between patients with normal-appearing breast tissue (3.56±0.54%Hz) and the fibroglandular breast tissue of healthy volunteers (3.70±0.68%Hz), no differences were observed (p=0.88). A moderate positive correlation was found between the APT signal and the proliferation index Ki-67 (r=0.61, p<0.01).

Conclusion:

Relaxation-compensated APT CEST MRI at 7T allowed a non-invasive differentiation of breast cancer lesions and normal-appearing breast tissue by quantifying increased protein-specific signal intensities in malignant tumours. Thus, APT CEST MRI represents a contrast agent-free method that may help to increase diagnostic accuracy in MR mammography.

Limitations:

The relatively small sample size (n = 17) prevents generalisation of the results. However, statistically meaningful results were obtained. 7T MRI devices are not widely available, which limits an immediate clinical translation of the presented approach.

Ethics committee approval

This prospective, monocentric study was approved by the local ethics committee. Written informed consent was obtained.

Funding:

No funding was received for this work.

Purpose:

To assess the diagnostic performance (DP) and tumour burden correlation of whole-body DWI with background suppression MRI (WB-DWIBS/MRI) in peritoneal carcinomatosis (PC) of suspected OC using the peritoneal cancer index (PCI) referring to cytoreduction surgery.

Methods and materials:

39/217 patients with disseminated OC underwent cytoreduction and WB-DWIBS/MRI. The PCI scored tumour burden (0-3) in 13 anatomical regions (global range of 0-39). Two radiologists (Rad1/Rad2) assessed the PCI preoperatively and with surgical findings.

We evaluated regional and global DP, the interobserver agreement, statistical differences (McNemar test), and correlation (Pearson’s test).

Results:

Global evaluation:
The overall positive scoring (PCI>0) for Rad1, Rad2, and surgery were 34.52%, 27.22%, and 31.76%, with a global average PCI 7.82, 8, and 8.44, respectively. The tumour burden correlation with surgery was 0.762 (p<0.001) for Rad1 and 0.642 (p<0.001) for Rad2. The sensibility, specificity, and accuracy were 0.84, 0.88, and 0.87. The global Kappa was 0.53.

Regional evaluation:
Kappa was moderate to substantial in 6/13 regions. The pelvis followed by the central region presented the highest number of positives and sensitivity. The bowel loops showed the lowest detection rate. Accuracy was over 0.86 in all regions for Rad1.

Conclusion:

WB-DWIBS/MRI is a reliable imaging technique that is useful in preoperatively quantifying and depicting PC in OC to achieve complete cytoreductive surgery.

Limitations:

A single institutional study. Occult selection bias as patients selected were also candidates for cytoreduction. Areas that may contraindicate resectability might be underevaluated. More than half were postoperative patients. DP may be affected. No direct comparison with other imaging techniques such as CT or PET/CT.

Ethics committee approval

Institutional review board approval and all patients signed written informed consent.

Funding:

No funding was received for this work.

Purpose:

To compare quantitative MRI (ADC values) and clinical parameters in patients with cervical cancer.

Methods and materials:

This MR study was retrospectively analysed in cervical cancer patients (n=133). Patients included in the study were non-surgical candidates with a locally advanced stage of 2B to 4A. Baseline MR imaging was done to assess the status of parametrial and ADC values. Post concurrent chemotherapy (CCT) and EBRT (external beam radiotherapy) assessment MRI was done and the ADC values were analysed in the region of interest. As per the institutional protocol, brachytherapy (ICRT/MUPIT) was done depending on the extent of parametrial invasion. The change of ADC values was charted separately, dividing the study groups into ICRT versus MUPIT. ICRT was given 100 patients and MUPIT 33. The 2 study groups were compared for the occurrence of recurrence and metastasis, stage, and nodal status, and statistical analysis was done to identify any significant correlation between baseline ADC, follow-up ADC, change in ADC, and recurrence-free survival among the groups.

Results:

The occurrence of recurrence and metastasis, stage, and nodal status correlated among 2 groups as p=0.002, 0.549, 0.029, and 0.184, respectively. 24/33 (72%) patients in the MUPIT group were stage 3 and 4. 49/100 (49%) patients in the ICRT group were stage 2. Age, baseline ADC, follow-up ADC, change in ADC, and recurrence-free survival among the groups were p=0.711, 0.931, 0.112, <0.0001, and <0.0001, respectively). The median recurrence-free survival for the ICRT group was 25 months and 9 months for the MUPIT group.

Conclusion:

A change in ADC is a potential surrogate marker for identifying between different choices of radiotherapy in uterine cervix cancer.

Limitations:

The small cohort.

Ethics committee approval

Ethics committee approval obtained.

Funding:

No funding was received for this work.