ElastoUS methods reduce unnecessary breast biopsies

By Kate Madden Yee, AuntMinnie.com staff writer

August 15, 2019 -- Using a combination of different elastography methods reduces unnecessary biopsies of BI-RADS 4 lesions without increasing the risk of missing cancers, according to a new study published in the September issue of Ultrasound in Medicine and Biology.

The findings suggest a better way to deal with BI-RADS 4 lesions, which can be tricky to assess for their potential to become malignant, according to a team led by Dr. Jing Han of Sun Yat-Sen University Cancer Center in Guangzhou, China.

"BI-RADS category 4 lesions exhibit a broad range of malignant potential (2% to 95%)," the group wrote (Ultrasound Med Biol, September 2019, Vol. 45:9, pp. 2317-2327). "Therefore, it is necessary to develop a noninvasive and reliable method to discern low-risk lesions as a complement to conventional ultrasound to reduce the unnecessary biopsy rate. Elastography has potential to serve as this valuable tool."

A key modality

Ultrasound is an important modality for breast cancer screening and differentiating benign from malignant lesions, but high false-positive rates can lead to unnecessary biopsies -- making the problem of reducing biopsy of benign lesions without missing cancers a key clinical issue, according to Han and colleagues. Ultrasound elastography may be just the ticket, they noted.

"Ultrasound elastography is beneficial for differentiating breast lesions in many studies," the team wrote. "This technique, which is sensitive to tissue stiffness, has been conducted as a complementary modality for improving breast lesion characterization."

There are a number of elastography techniques: strain (SE), shear wave (SWE), virtual touch imaging (VTi), and virtual touch imaging quantification (VTIQ). Each has its benefits and limitations, and studies have shown that using conventional ultrasound with a single elastography technique can reduce false-positive rates but also increase false-negative rates. Han and colleagues sought to investigate what combinations of strain elastography, VTi, and VTIQ might reduce false positives without increasing false negatives in evaluating BI-RADS category 4 lesions.

The study included 267 patients with 278 BI-RADS 4 lesions who were scheduled for ultrasound-guided biopsy between January 2016 and May 2017. Of the 278 lesions, 151 were benign and 127 were malignant. All were evaluated with conventional B-mode ultrasound, strain elastography, SWE, VTi, and VTIQ (SWE was used with VTIQ; the researchers did not break it out as an individual elastography category for assessment).

Han and colleagues evaluated the following factors: diagnostic performance (including area under the receiver operating characteristic curve, or AUC) sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV).

The group found that VTi alone showed the highest negative predictive value at 91.7%, although combined methods showed higher negative predictive value than single methods, with the highest negative predictive value at 100% when VTi, SE, and VTIQ were combined.

Han's team also found that, compared with conventional ultrasound, positive predictive value increased from 45.7% to 63.1% when combined elastography was added (VTi plus SE plus VTIQ). Of the BI-RADS 4 lesions, 52.5% were downgraded when using a combination of VTi plus SE, and 50.8% were downgraded when using VTi plus strain elastography plus VTIQ -- without missing any cancer.

Performance of elastography techniques for reducing unnecessary biopsy of BI-RADS 4 breast lesions
Performance measure	SE	VTi	VTIQ	VTIQ plus VTi	VITQ plus SE	VTi plus SE	VTi, SE, & VTIQ
Sensitivity	89.7%	92.1%	85%	96.8%	98.4%	99.2%	100%
Specificity	63.5%	73.5%	84.7%	67.5%	59.6%	52.9%	50.9%
Accuracy	75.5%	82%	84.9%	80%	77.3%	74.1%	73.4%
PPV	67.4%	74.5%	82.4%	71.5%	67.2%	63.9%	63.1%
NPV	88%	91.7%	87%	96.2%	97.8%	98.7%	100%
AUC	0.82	0.84	0.90	0.82	0.79	0.76	0.75

As for statistical significance, the group found that the specificity and area under the receiver operating curve of VTIQ were significantly higher than those of SE and VTi, and the sensitivity of combined methods was significantly higher than single methods.

Effective combinations

More research is needed to determine the role of combined elastography techniques in reducing unnecessary biopsies of BI-RADS 4 breast lesions, according to Han and colleagues.

"Our initial clinical result revealed that the combination of different types of elastography could improved the sensitivity and negative predictive value, which might serve as a complementary approach to conventional ultrasound to ... reduce unnecessary biopsy for benign breast lesions," the team concluded. "Further studies with a larger population are required to validate our results."

Cardiac US at bedside boosts disease diagnosis.

By Kate Madden Yee, AuntMinnie.com staff writer

August 6, 2019 -- Adding focused cardiac ultrasonography (FoCUS) to clinical assessment of the cardiovascular health of patients at bedside improves diagnostic yield, according to a study published online August 5 in the Annals of Internal Medicine.

The findings offer clinicians a way to update the traditional "standard of care" bedside evaluation -- that is, a history and physical exam -- for cardiovascular disease, wrote a team led by Dr. Jeffrey Marbach of the University of Ottawa Heart Institute in Ontario, Canada.

"The limited evidence that supports 'classical' signs and symptoms of cardiovascular disease was observed in an era when late-stage presentation was common and detection of disease before onset of symptoms was rare," the authors wrote. "A more sensitive bedside toolkit to detect and quantify pathology before onset of progressive organ damage is increasingly needed, both to triage patients for more formal testing and to allow more rapid clinical decisions at the point of care."

The benefits of POC

Ultrasound has a wide array of imaging capabilities and can be used with everything from superficial vasculature to large intra-abdominal organs to cardiac chambers, the team noted. As such, point-of-care (POC) ultrasound is often used with bedside procedures such as central venous catheter insertion or pericardiocentesis.

The modality's use at bedside hasn't been broadly adopted, even though physical examination is understood to be often inaccurate. But interest in using ultrasound at bedside has increased, Marbach and colleagues wrote.

"Because a small but growing body of literature suggests potential advantages of adjunctive ultrasonography evaluation with physical examination, interest in its accuracy and applicability is increasing," the team wrote. "The possibilities for diagnostic improvement are particularly promising in patients requiring cardiovascular evaluation."

Transthoracic echocardiography has long been used for this purpose; its practitioners are trained in cardiac imaging. Bedside FoCUS offers a quicker, more easily repeatable way to perform a cardiovascular assessment, corresponding author Dr. Benjamin Hibbert, PhD, also of the University of Ottawa Heart Institute, told AuntMinnie.com.

"Our center has been using FoCUS for close to 10 years now, and it has completely changed our practice," he said. "We realized early that adding a FoCUS to physical exam provided meaningful incremental information at the bedside to help in diagnosing and managing our patients. This was even more apparent in our critically ill patients where rapid decisions needed to be made."

Increased sensitivity

For the study, the researchers conducted a review of Medline, Embase, and Web of Science for articles published between January 1990 to May 2019 that compared FoCUS-assisted clinical assessment with clinical assessment alone for the diagnosis of left ventricular systolic dysfunction, aortic or mitral valve disease, or pericardial effusion. They used transthoracic echocardiography as the reference standard. The group included nine studies in its analysis.

The authors found that adding FoCUS to clinical examination at bedside for cardiovascular applications did improve diagnostic yield -- with increased sensitivity and specificity for diagnosing left ventricular dysfunction, and increased sensitivity for diagnosing aortic or mitral valve disease.

Performance of FoCUS when added to clinical exam at bedside
Performance measure	Clinical assessment alone	FoCUS-assisted clinical examination
Sensitivity
Diagnosing left ventricular dysfunction	43%	84%
Diagnosing aortic or mitral valve disease	46%	71%
Specificity
Diagnosing left ventricular dysfunction	81%	89%
Diagnosing aortic or mitral valve disease	94%	94%

The findings indicate that using FoCUS with clinical assessment allows for greater detection of disease that might otherwise be missed by clinical assessment alone, Hibbert told AuntMinnie.com.

"The take-home message is that the standard assessment for cardiac pathology is limited, and adding a FoCUS to your assessment markedly increases your ability to detect pathology," he said. "While not directly addressed in this study, the next logical step is going to be seeing if we can use FoCUS to appropriately triage patients for formal echocardiography, which is often performed as a screening test. All healthcare systems are strapped for resources, and if we can rule out significant pathology with a careful exam and FoCUS, we may be able to safely defer formal testing in a large number of patients."l