An intraoperative 3D ultrasound system for tumor margin determination in breast cancer surgery

Ultrasound-guided preoperative localization of breast lesions: a good choice

PURPOSE

The aim of the study was to verify whether ultrasound (US)-guided preoperative localization of breast lesions is an adequate technique for correct and safe surgical resection and to contribute positively and effectively to this topic in the literature with our results.

METHODS

From June 2016 to November 2016, 155 patients with both benign and malignant breast lesions were selected from our institute to undergo US localization before surgery. The lesions included were: sonographically visible and nonpalpable lesions; palpable lesions for which a surgeon had requested US localization to better evaluate the site and extension; sonographically visible, multifocal breast lesions, both palpable and nonpalpable. US localization was performed using standard linear transducers (Siemens 18 L6, 5.5-8 MHz, 5.6 cm, ACUSON S2000 System, Siemens Medical Solutions). The radiologist used a skin pen to mark the site of the lesion, and the reported lesion's depth and distance from the nipple and pectoral muscle were recorded. The lesions were completely excised by a team of breast surgeons, and the surgical specimens were sent to the Radiology Department for radiological evaluation and to the Pathology Department for histological assessment.

RESULTS

In 155 patients who underwent to preoperative US localization, 188 lesions were found, and the location of each lesion was marked with a skin pen. A total of 181 lesions were confirmed by the final histopathologic exam (96.28%); 132 of them (72.92%) were malignant, and 124 of these (93.93%) showed free margins.

CONCLUSIONS

US-guided preoperative localization of sonographically visible breast lesions is a simple and nontraumatic procedure with high specificity and is a useful tool for obtaining accurate surgical margins.

Intraoperative ultrasound in breast cancer surgery-from localization of non-palpable tumors to objectively measurable excision

Background

The utilization of intraoperative ultrasound (IOUS) in breast cancer surgery is a relatively new concept in surgical oncology. Over the last few decades, the field of breast cancer surgery has been striving for a more rational approach, directing its efforts towards removing the tumor entirely yet sparing tissue and structures not infiltrated by tumor cells. Further progress in objectivity and optimization of breast cancer excision is possible if we make the tumor and surrounding tissue visible and measurable in real time, during the course of the operation; IOUS seems to be the optimal solution to this complex requirement. IOUS was introduced into clinical practice as a device for visualization of non-palpable tumors, and compared to wire-guided localization (WGL), IOUS was always at least a viable, or much better alternative, in terms of both precision in identification and resection and for patients’ and surgeons’ comfort. In recent years, intraoperative ultrasound has been used in the surgery of palpable tumors to optimize resection procedures and overcome the disadvantages of classic palpation guided surgery.

Objective

The aim of this review is to show the role of IOUS in contemporary breast cancer surgery and its changes over time.

Methods

A PubMed database comprehensive search was conducted to identify all relevant articles according to assigned key words.

Conclusion

Over time, the use of IOUS has been transformed from being the means of localizing non-palpable lesions to an instrument yielding a reduced number of positive resection margins, with a smaller volume of healthy breast tissue excided around tumor, by making the excision of the tumor optimal and objectively measurable.

Current status of ultrasound-guided surgery in the treatment of breast cancer

The primary goal of breast-conserving surgery (BCS) is to obtain tumour-free resection margins. Margins positive or focally positive for tumour cells are associated with a high risk of local recurrence, and in the case of tumour-positive margins, re-excision or even mastectomy are sometimes needed to achieve definite clear margins. Unfortunately, tumour-involved margins and re-excisions after lumpectomy are still reported in up to 40% of patients and additionally, unnecessary large excision volumes are described. A secondary goal of BCS is the cosmetic outcome and one of the main determinants of worse cosmetic outcome is a large excision volume. Up to 30% of unsatisfied cosmetic outcome is reported. Therefore, the search for better surgical techniques to improve margin status, excision volume and consequently, cosmetic outcome has continued. Nowadays, the most commonly used localization methods for BCS of non-palpable breast cancers are wire-guided localization (WGL) and radio-guided localization (RGL). WGL and RGL are invasive procedures that need to be performed pre-operatively with technical and scheduling difficulties. For palpable breast cancer, tumour excision is usually guided by tactile skills of the surgeon performing “blind” surgery. One of the surgical techniques pursuing the aims of radicality and small excision volumes includes intra-operative ultrasound (IOUS). The best evidence available demonstrates benefits of IOUS with a significantly high proportion of negative margins compared with other localization techniques in palpable and non-palpable breast cancer. Additionally, IOUS is non-invasive, easy to learn and can centralize the tumour in the excised specimen with low amount of healthy breast tissue being excised. This could lead to better cosmetic results of BCS. Despite the advantages of IOUS, only a small amount of surgeons are performing this technique. This review aims to highlight the position of ultrasound-guided surgery for malignant breast tumours in the search for better oncological and cosmetic outcomes.

Optimization of breast cancer excision by intraoperative ultrasound and marking needle - technique description and feasibility

Background

We present a surgical technique and the preliminary results of breast cancer excision after insertion of a specially constructed marking needle into the tumor, controlled by intraoperative ultrasound.

Resection margins were projected in six directions by ultrasound measurements, determined in relation to the needle, and resection was done in accordance with those measurements. The main objective was to obtain resection margins similar (equal) to those projected by intraoperative ultrasound (10 mm).

Methods

Detailed description of the technique is given. Thirty-two female patients undergoing breast-conserving surgery, up to 30 mm in diameter, for palpable and non-palpable invasive breast cancer, were operated on using this technique. Its feasibility was tested by analyzing the success (rate) of needle placement in the tumor, the measurements executed, and the performance of the excision.

Results

All stages of the technique were successfully performed to completion on all 32 patients. The procedure of needle placement and ultrasound measurement of distances took 11 min on average (between 6 and 20 min). The average distance of the tumor margin from the resection margin was 12.9 mm (2 to 30 mm, 95% confidence interval [11.9, 14.06]). There was one patient with a positive resection margin (3%).

Conclusions

The technique of excising palpable and non-palpable breast cancer by intraoperative ultrasound and an especially constructed marking needle is feasible and comfortable to perform. Preliminary results imply that resection volume can be rationalized, with the same or better oncological safety.

Optimization of breast cancer excision by intraoperative ultrasound and marking needle - technique description and feasibility

BACKGROUND

We present a surgical technique and the preliminary results of breast cancer excision after insertion of a specially constructed marking needle into the tumor, controlled by intraoperative ultrasound. Resection margins were projected in six directions by ultrasound measurements, determined in relation to the needle, and resection was done in accordance with those measurements. The main objective was to obtain resection margins similar (equal) to those projected by intraoperative ultrasound (10 mm).

METHODS

Detailed description of the technique is given. Thirty-two female patients undergoing breast-conserving surgery, up to 30 mm in diameter, for palpable and non-palpable invasive breast cancer, were operated on using this technique. Its feasibility was tested by analyzing the success (rate) of needle placement in the tumor, the measurements executed, and the performance of the excision.

RESULTS

All stages of the technique were successfully performed to completion on all 32 patients. The procedure of needle placement and ultrasound measurement of distances took 11 min on average (between 6 and 20 min). The average distance of the tumor margin from the resection margin was 12.9 mm (2 to 30 mm, 95% confidence interval [11.9, 14.06]). There was one patient with a positive resection margin (3%).

CONCLUSIONS

The technique of excising palpable and non-palpable breast cancer by intraoperative ultrasound and an especially constructed marking needle is feasible and comfortable to perform. Preliminary results imply that resection volume can be rationalized, with the same or better oncological safety.

Breast ultrasonography: state of the art

Ultrasonography (US) is an indispensable tool in breast imaging and is complementary to both mammography and magnetic resonance (MR) imaging of the breast. Advances in US technology allow confident characterization of not only benign cysts but also benign and malignant solid masses. Knowledge and understanding of current and emerging US technology, along with the application of meticulous scanning technique, is imperative for image optimization and diagnosis. The ability to synthesize breast US findings with multiple imaging modalities and clinical information is also necessary to ensure the best patient care. US is routinely used to guide breast biopsies and is also emerging as a supplemental screening tool in women with dense breasts and a negative mammogram. This review provides a summary of current state-of-the-art US technology, including elastography, and applications of US in clinical practice as an adjuvant technique to mammography, MR imaging, and the clinical breast examination. The use of breast US for screening, preoperative staging for breast cancer, and breast intervention will also be discussed.

3D ultrasound system to investigate intraventricular hemorrhage in preterm neonates

Intraventricular hemorrhage (IVH) is a common disorder among preterm neonates that is routinely diagnosed and monitored by 2D cranial ultrasound (US). The cerebral ventricles of patients with IVH often have a period of ventricular dilation (ventriculomegaly). This initial increase in ventricle size can either spontaneously resolve, which often shows clinically as a period of stabilization in ventricle size and eventual decline back towards a more normal size, or progressive ventricular dilation that does not stabilize and which may require interventional therapy to reduce symptoms relating to increased intracranial pressure. To improve the characterization of ventricle dilation, we developed a 3D US imaging system that can be used with a conventional clinical US scanner to image the ventricular system of preterm neonates at risk of ventriculomegaly. A motorized transducer housing was designed specifically for hand-held use inside an incubator using a transducer commonly used for cranial 2D US scans. This system was validated using geometric phantoms, US/MRI compatible ventricle volume phantoms, and patient images to determine 3D reconstruction accuracy and inter- and intra-observer volume estimation variability. 3D US geometric reconstruction was found to be accurate with an error of <0.2%. Measured volumes of a US/MRI compatible ventricle-like phantom were within 5% of gold standard water displacement measurements. Intra-class correlation for the three observers was 0.97, showing very high agreement between observers. The coefficient of variation was between 1.8-6.3% for repeated segmentations of the same patient. The minimum detectable difference was calculated to be 0.63 cm(3) for a single observer. Results from ANOVA for three observers segmenting three patients of IVH grade II did not show any significant differences (p > 0.05) for the measured ventricle volumes between observers. This 3D US system can reliably produce 3D US images of the neonatal ventricular system. There is the potential to use this system to monitor the progression of ventriculomegaly over time in patients with IVH.

Three-dimensional ultrasonography for breast malignancy detection

INTRODUCTION

Breast ultrasound is used not only to differentiate a solid breast mass from a cyst and to assist in guided biopsy, but also to classify benign and malignant lesions, with good resolution gray-scale imaging equipped with color Doppler adequate for daily clinical practice in most circumstances.

AREAS COVERED

This article critically reviews three-dimensional (3D) ultrasound for the detection of breast malignancies in comparison with the popular two-dimensional ultrasound, highlighting the advantages it has over other imaging modalities as well as the drawbacks that are presented. In particular, the article looks at how 3D ultrasound planes help us to define more clearly the margins, that is, microlobulation and papillomas, of breast tumors. This paper also highlights how the resolution and multiple planes of 3D ultrasound can clearly demonstrate skin tumor infiltration for evaluation and how it can be used for planning, monitoring and treatment of breast cancer.

EXPERT OPINION

As with any new technology, 3D ultrasound has a learning curve and clinicians will need to master the technology in order to use this tool to its full potential. Although 3D ultrasound does have its limitations, a better understanding of its settings along with the optimization of image acquisition and a better ability to manipulate data during analysis will lead to 3D ultrasound becoming a useful tool for breast malignancy detection.