Nicky H. G. M. Peters

Preoperative MRI and surgical management in patients with nonpalpable breast cancer: The MONET - Randomised controlled trial

BACKGROUND We evaluated whether performing contrast-enhanced breast MRI in addition to mammography and/or ultrasound in patients with nonpalpable suspicious breast lesions improves breast cancer management. METHODS The MONET - study (MR mammography of nonpalpable breast tumours) is a randomised controlled trial in patients with a nonpalpable BIRADS 3-5 lesion. Patients were randomly assigned to receive routine medical care, including mammography, ultrasound and lesion sampling by large core needle biopsy or additional MRI preceding biopsy. Patients with cancer were referred for surgery. Primary end-point was the rate of additional surgical procedures (re-excisions and conversion to mastectomy) in patients with a nonpalpable breast cancer. FINDINGS Four hundred and eighteen patients were randomised, 207 patients were allocated to MRI, and 211 patients to the control group. In the MRI group 74 patients had 83 malignant lesions, compared to 75 patients with 80 malignant lesions in the control group. The primary breast conserving surgery (BCS) rate was similar in both groups; 68% in the MRI group versus 66% in the control group. The number of re-excisions performed because of positive resection margins after primary BCS was increased in the MRI group; 18/53 (34%) patients in the MRI group versus 6/50 (12%) in the control group (p=0.008). The number of conversions to mastectomy did not differ significantly between groups. Overall, the rate of an additional surgical intervention (BCS and mastectomy combined) after initial breast conserving surgery was 24/53 (45%) in the MRI group versus 14/50 (28%) in the control group (p=0.069). INTERPRETATION Addition of MRI to routine clinical care in patients with nonpalpable breast cancer was paradoxically associated with an increased re-excision rate. Breast MRI should not be used routinely for preoperative work-up of patients with nonpalpable breast cancer.

Quantitative diffusion weighted imaging for differentiation of benign and malignant breast lesions: The influence of the choice of b‐values

To evaluate the influence of the choice of different combinations of b‐values on the ADC and on the diagnostic performance of quantitative diffusion weighted imaging (DWI) in breast lesions.

Do respiration and cardiac motion induce magnetic field fluctuations in the breast and are there implications for MR thermometry

To assess the distribution of respiration and cardiac motion‐induced field fluctuations in the breast and to evaluate the implications of such fluctuations for proton resonance frequency shift (PRFS) MR thermometry in the breast.

Breast MRI in nonpalpable breast lesions: a randomized trial with diagnostic and therapeutic outcome – MONET – study

BackgroundIn recent years there has been an increasing interest in MRI as a non-invasive diagnostic modality for the work-up of suspicious breast lesions. The additional value of Breast MRI lies mainly in its capacity to detect multicentric and multifocal disease, to detect invasive components in ductal carcinoma in situ lesions and to depict the tumor in a 3-dimensional image. Breast MRI therefore has the potential to improve the diagnosis and provide better preoperative staging and possibly surgical care in patients with breast cancer. The aim of our study is to assess whether performing contrast enhanced Breast MRI can reduce the number of surgical procedures due to better preoperative staging and whether a subgroup of women with suspicious nonpalpable breast lesions can be identified in which the combination of mammography, ultrasound and state-of-the-art contrast-enhanced Breast MRI can provide a definite diagnosis.Methods/DesignThe MONET – study (M R mammography O f N onpalpable BrE ast T umors) is a randomized controlled trial with diagnostic and therapeutic endpoints. We aim to include 500 patients with nonpalpable suspicious breast lesions who are referred for biopsy. With this number of patients, the expected 12% reduction in surgical procedures due to more accurate preoperative staging with Breast MRI can be detected with a high power (90%). The secondary outcome is the positive and negative predictive value of contrast enhanced Breast MRI. If the predictive values are deemed sufficiently close to those for large core biopsy then the latter, invasive, procedure could possibly be avoided in some women. The rationale, study design and the baseline characteristics of the first 100 included patients are described.Trial registrationStudy protocol number NCT00302120

Deep Learning for Fully-Automated Localization and Segmentation of Rectal Cancer on Multiparametric MR

Multiparametric Magnetic Resonance Imaging (MRI) can provide detailed information of the physical characteristics of rectum tumours. Several investigations suggest that volumetric analyses on anatomical and functional MRI contain clinically valuable information. However, manual delineation of tumours is a time consuming procedure, as it requires a high level of expertise. Here, we evaluate deep learning methods for automatic localization and segmentation of rectal cancers on multiparametric MR imaging. MRI scans (1.5T, T2-weighted, and DWI) of 140 patients with locally advanced rectal cancer were included in our analysis, equally divided between discovery and validation datasets. Two expert radiologists segmented each tumor. A convolutional neural network (CNN) was trained on the multiparametric MRIs of the discovery set to classify each voxel into tumour or non-tumour. On the independent validation dataset, the CNN showed high segmentation accuracy for reader1 (Dice Similarity Coefficient (DSC = 0.68) and reader2 (DSC = 0.70). The area under the curve (AUC) of the resulting probability maps was very high for both readers, AUC = 0.99 (SD = 0.05). Our results demonstrate that deep learning can perform accurate localization and segmentation of rectal cancer in MR imaging in the majority of patients. Deep learning technologies have the potential to improve the speed and accuracy of MRI-based rectum segmentations.

Quantitative analysis of lumbar intervertebral disc abnormalities at 3.0 Tesla: value of T2 texture features and geometric parameters

T2 relaxation time mapping provides information about the biochemical status of intervertebral discs. The present study aimed to determine whether texture features extracted from T2 maps or geometric parameters are sensitive to the presence of abnormalities at the posterior aspect of lumbar intervertebral discs, i.e. bulging and herniation. Thirty‐one patients (21 women and 10 men; age range 18–51 years) with low back pain were enrolled. MRI of the lumbar spine at 3.0 Tesla included morphological T1‐ and T2‐weighted fast spin‐echo sequences, and multi‐echo spin‐echo sequences that were used to construct T2 maps. On morphological MRI, discs were visually graded into ‘normal’, ‘bulging’ or ‘herniation’. On T2 maps, texture analysis (based on the co‐occurrence matrix and wavelet transform) and geometry analysis of the discs were performed. The three T2 texture features and geometric parameters best‐suited for distinguishing between normal discs and discs with bulging or herniation were determined using Fisher coefficients. Statistical analysis comprised ANCOVA and post hoc t‐tests. Eighty‐two discs were classified as ‘normal’, 49 as ‘bulging’ and 20 showed ‘herniation.’ The T2 texture features Entropy and Difference Variance, and all three pre‐selected geometric parameters differed significantly between normal and bulging, normal and herniated, and bulging and herniated discs (p < 0.05). These findings suggest that T2 texture features and geometric parameters are sensitive to the presence of abnormalities at the posterior aspect of lumbar intervertebral discs, and may thus be useful as quantitative biomarkers that predict disease. Copyright

Current clinical indications for magnetic resonance imaging of the breast

MRI is increasingly used in breast cancer patients. MRI has a high sensitivity compared to mammography and ultrasound. The specificity is moderate leading to an increased risk of false positive findings. Currently, a beneficial effect of breast MRI has been established in some patient groups and is debated in the general breast cancer population. The diagnostic ability of MRI and its role in various groups of breast cancer patients are discussed in this review. J. Surg. Oncol. 2014 110:26–31.

Diagnostic performance of stereotactic large core needle biopsy for nonpalpable breast lesions in routine clinical practice

The COBRA (COre Biopsy after RAdiological localization) study showed that in a controlled study setting, stereotactic large core needle biopsy (LCNB) is as reliable for diagnosing nonpalpable breast lesions as open surgical biopsy. In the present study, we evaluated the diagnostic performance of stereotactic LCNB in routine clinical practice. Between February 2000 and June 2002, data on all patients (n = 955) with nonpalpable breast lesions referred for LCNB were collected. High risk underestimate rate, ductal carcinoma in situ (DCIS) underestimate rate and sensitivity rate after 2 years were calculated. The usefulness of the COBRA guidelines in clinical practice was determined. Nine hundred five successful biopsies were performed in 874 patients. Of the high‐risk lesions, 27% were found to be carcinomas on open biopsy, which is comparable to the results of the COBRA study (23%). The DCIS underestimate rate (28%) was higher than found in the COBRA study (17%). No carcinomas were missed after a follow‐up period of 2 years. Ninety‐six percent of patients were treated according to the COBRA guidelines. The diagnostic performance of stereotactic LCNB in patients with nonpalpable breast lesions seems to be comparable in a controlled study setting and routine clinical practice.

The added diagnostic value of dynamic contrast-enhanced MRI at 3.0 T in nonpalpable breast lesions

Objective To investigate the added diagnostic value of 3.0 Tesla breast MRI over conventional breast imaging in the diagnosis of in situ and invasive breast cancer and to explore the role of routine versus expert reading. Materials and Methods We evaluated MRI scans of patients with nonpalpable BI-RADS 3–5 lesions who underwent dynamic contrast-enhanced 3.0 Tesla breast MRI. Initially, MRI scans were read by radiologists in a routine clinical setting. All histologically confirmed index lesions were re-evaluated by two dedicated breast radiologists. Sensitivity and specificity for the three MRI readings were determined, and the diagnostic value of breast MRI in addition to conventional imaging was assessed. Interobserver reliability between the three readings was evaluated. Results MRI examinations of 207 patients were analyzed. Seventy-eight of 207 (37.7%) patients had a malignant lesion, of which 33 (42.3%) patients had pure DCIS and 45 (57.7%) invasive breast cancer. Sensitivity of breast MRI was 66.7% during routine, and 89.3% and 94.7% during expert reading. Specificity was 77.5% in the routine setting, and 61.0% and 33.3% during expert reading. In the routine setting, MRI provided additional diagnostic information over clinical information and conventional imaging, as the Area Under the ROC Curve increased from 0.76 to 0.81. Expert MRI reading was associated with a stronger improvement of the AUC to 0.87. Interobserver reliability between the three MRI readings was fair and moderate. Conclusions 3.0 T breast MRI of nonpalpable breast lesions is of added diagnostic value for the diagnosis of in situ and invasive breast cancer.

Breast Magnetic Resonance Imaging in Early-Stage Breast Cancer: Is There Really No Value?

IN REPLY: We appreciate Dr Prommer’s letter and would like to make several comments in reply. The type of opioid-induced hyperalgesia (OIH) described in our case report does not involve most of the cellular and subcellular mechanisms described in detail by Dr Prommer. Outlined mechanisms apply to OIH associated with opioid maintenance doses and/or opioid withdrawal (OIHMW). However, the case presented by us concerned OIH associated with the use of very high and escalating opioid doses (OIHHD). This type of OIH is not mediated through the opioid receptor system. From a mechanistic and management point of view it is important to differentiate OIHMW from OIHHD. 1