Breast lesion detection through MammoWave device: microwave images’ parameters

MammoWave is a microwave imaging device for breast lesions detection, which operates using two (azimuthally rotating) antennas without any matching liquid. Images, subsequently obtained by resorting to Huygens Principle, are intensity maps, representing the homogeneity of tissues’ dielectric properties. In the paper: “Breast lesion detection through MammoWave device: empirical detection capability assessment of microwave images’ parameters”, we propose to generate, for each breast, a set of conductivity weighted microwave images by using different values of conductivity in the Huygens Principle imaging algorithm. Next, microwave images’ parameters, i.e. features, are introduced to quantify the non-homogenous behaviour of the image. This data set contains such features. We empirically verify on 103 breasts that a selection of these features may allow distinction between breasts with no radiological finding (NF ) and breasts with radiological findings (WF), i.e. with lesions which may be benign or malign. Statistical significance was set at p <0.05. We obtained single features Area Under the receiver operating characteristic Curves (AUCs) spanning from 0.65 to 0.69. In addition, an empirical rule-of-thumb allowing breast assessment is introduced using a binary score S operating on an appropriate combination of features. Performances of such rule-of-thumb are evaluated empirically, obtaining a sensitivity of 74%, which increases to 84% when considering dense breasts only

Identificazione e caratterizzazione dei microRNA coinvolti nel Mesotelioma Pleurico Maligno

One of the research areas of modern medicine is to work on the identification of biological markers, such as biomolecular ones, for neoplastic diseases from occupational origin. MiRNA, short RNA no-codifing sequences, are recently identified such as diagnostic markers in several type of cancer. For this reason, the aim of our study is to analyze the possible role of miRNA in malignant pleural mesothelioma, a rare and aggressive tumor with a strong resistance to conventional therapies and poor prognosis. Total RNA, containing also miRNA, was extracted, and RNA was retro-transcripted with specific primers. Then, miRNA expression was tested using real-time PCR method and particular probes for each miRNA. The RNU6B was used such as housekeeping gene, for data normalization. This work represents the first step for the identification of a specific miRNA pattern for MPM, which will be useful in the diagnosis of MPM and for a personalized therapeutic treatment

A Multicentric, Single Arm, Prospective, Stratified Clinical Investigation to Confirm MammoWave’s Ability in Breast Lesions Detection

Novel techniques, such as microwave imaging, have been implemented in different prototypes and are under clinical validation, especially for breast cancer detection, due to their harmless technology and possible clinical advantages over conventional imaging techniques. In the prospective study presented in this work, we aim to investigate through a multicentric European clinical trial (ClinicalTrials.gov Identifier NCT05300464) the effectiveness of the MammoWave microwave imaging device, which uses a Huygens-principle-based radar algorithm for image reconstruction and comprises dedicated image analysis software. A detailed clinical protocol has been prepared outlining all aspects of this study, which will involve adult females having a radiologist study output obtained using conventional exams (mammography and/or ultrasound and/or magnetic resonance imaging) within the previous month. A maximum number of 600 volunteers will be recruited at three centres in Italy and Spain, where they will be asked to sign an informed consent form prior to the MammoWave scan. Conductivity weighted microwave images, representing the homogeneity of the tissues’ dielectric properties, will be created for each breast, using a conductivity = 0.3 S/m. Subsequently, several microwave image parameters (features) will be used to quantify the images’ non-homogenous behaviour. A selection of these features is expected to allow for distinction between breasts with lesions (either benign or malignant) and those without radiological findings. For all the selected features, we will use Welch’s t-test to verify the statistical significance, using the gold standard output of the radiological study review

Fig 1 -

MammoWave system, sketch of the breast imaging configuration showing the cylindrical hub and the antennas (left). Transmitting and receiving antenna configuration, showing the five triplet sections (right).</p

Example of NF breast: 50 years old woman, mammographic low-density (ACR B), left breast (DBT and ultrasonography BI-RADS 1).

Microwave images, normalized to unitary average of the intensity, are given in the top row for three different conductivity weightings (from left to right: 0.3 S/m, 0.4 S/m and 0.5 S/m, respectively). Microwave images are given here as 2D images in the azimuthal, i.e., coronal plane. Moreover, 1D intensity projection on X and Y is displayed in the inserts. X and Y are given in meters; intensity is in arbitrary units. The proposed rule-of-thumb classifies this breast as negative (the values of the microwave images’ selected features are provided in the S1B Table).</p

Example of WF breast: Mammographic high-density (ACR D), left breast of 66 years old woman, with a group of microcalcifications.

Histopathology output is also given in the insert. Microwave images, normalized to unitary average of the intensity, are given in the top row for three different conductivity weightings (from left to right: 0.3 S/m, 0.4 S/m and 0.5 S/m, respectively). Microwave images are given here as 2D images in the azimuthal, i.e., coronal plane. Moreover, 1D intensity projection on X and Y is displayed in the inserts. X and Y are given in meters; intensity is in arbitrary units. All microwave images show a non-homogeneous behavior, with a main peak indicated by the red arrows. The proposed rule-of-thumb classifies this breast as positive (the values of the microwave images’ selected features are provided in the S1B Table).</p

Example of WF breast: Mammographic low density (ACR B) left breast of 70 years old woman with a mammographic parenchymal distortion of 8 mm confirmed by DBT in the lower outer quadrant.

Histopathology output is also given in the insert. Microwave images, normalized to unitary average of the intensity, are given in the top row for three different conductivity weightings (from left to right: 0.3 S/m, 0.4 S/m and 0.5 S/m, respectively). Microwave images are given here as 2D images in the azimuthal, i.e., coronal plane. Moreover, 1D intensity projection on X and Y is displayed in the inserts. X and Y are given in meters; intensity is in arbitrary units. All microwave images show a non-homogeneous behavior, with a main peak indicated by the red arrows. The proposed rule-of-thumb classifies this breast as positive (the values of the microwave images’ selected features are provided in the S1B Table).</p

Clinical trial’s workflow of the second phase.

Prior to the kick-off of the second phase, 15 participants in each centre, all having NF breasts, have been examined by MammoWave and data has been used to calibrate the image parameters’ thresholds. MammoWave images were reviewed by a central assessor (an independent external scientist), who had no access to the reference standard data; the central assessor discarded MammoWave outputs due to the presence of spurious peaks in MammoWave images. Subsequently, the microwave imaging output of MammoWave is compared to the output of the radiologist study review (from conventional exams).</p

Example of WF breast: Mammographic heterogeneously dense (ACR C) right breast of 50 years old woman with a palpable nodule of 10 mm.

Histopathology output is also given in the insert. Microwave images, normalized to unitary average of the intensity, are given in the top row for three different conductivity weightings (from left to right: 0.3 S/m, 0.4 S/m and 0.5 S/m, respectively). Microwave images are given here as 2D images in the azimuthal, i.e., coronal plane. Moreover, 1D intensity projection on X and Y is displayed in the inserts. X and Y are given in meters; intensity is in arbitrary units. All microwave images show a non-homogeneous behavior, with a main peak indicated by the red arrows. The proposed rule-of-thumb classifies this breast as positive (the values of the microwave images’ selected features are provided in the S1B Table).</p

S1 Appendix -

Microwave imaging is a safe and promising new technology in breast radiology, avoiding discomfort of breast compression and usage of ionizing radiation. This paper presents the first prospective microwave breast imaging study during which both symptomatic and asymptomatic subjects were recruited. Specifically, a prospective multicentre international clinical trial was performed in 2020–2021, to investigate the capability of a microwave imaging device (MammoWave) in allowing distinction between breasts with no radiological finding (NF) and breasts with radiological findings (WF), i.e., with benign or malignant lesions. Each breast scan was performed with the volunteers lying on a dedicated examination table in a comfortable prone position. MammoWave output was compared to reference standard (i.e., radiologic study obtained within the last month and integrated with histological one if available and deemed necessary by responsible investigator) to classify breasts into NF/WF categories. MammoWave output consists of a selection of microwave images’ features (determined prior to trials’ start), which allow distinction between NF and WF breasts (using statistical significance p</div