Imaging tech not good enough to reduce needless breast biopsies
A large-scale study of mammography exams has found that clinicians are too quick to order invasive biopsies because of high rates of false positive results from initial imaging examinations.
The national study, published in ClinicoEconomics and Outcomes Research, pulled data from a sample of 875,000 women, and sought to determine the extent of follow-up procedures after initial screenings, such as mammography or breast examinations, showed suspicious findings.
The study estimates the annual cost of false-positive breast biopsies exceeds $2.1 billion, with a total annual price tag of $8 billion in total expenses, including the costs of additional breast diagnostic testing. It was conducted by a team of health outcomes research scientists at IBM Watson Health in collaboration with Seno Medical.
The results underscore the need for improved breast imaging and diagnostic tools, researchers say. False positive rates—which occur when initial imaging exams find something suspicious that is later found to be of no consequence—can be as high as 71 percent of all biopsies, the researchers estimated.
Potential solutions include improved imaging technology and more extensive follow-up with patients before invasive procedures are attempted.
For example, just-published research from Italy suggests that the addition of tomosynthesis to digital mammography improved the detection of breast cancer by 90 percent, according to researchers in Italy. Breast tomosynthesis—also called three-dimensional (3-D) mammography and digital breast tomosynthesis—is an advanced form of breast imaging that uses a low-dose X-ray system and computer reconstructions to create three-dimensional images of the breasts.
The US study conducted by IBM Watson Health and Seno Medical used data collected from real encounters from claims data over a four-year period. This sample then was used to estimate that more than 12 million women in the nation get follow-up exams because of suspicious findings. The follow-up exams are ordered by clinicians because current tools often do not provide diagnostic certainty in identifying cancerous breast masses, according to the study.
Authors further note the need for more effective examination tools that could exclude patients whose suspicious breast masses are benign before they are subjected to invasive diagnostic procedures.
“The costs to the healthcare system are secondary to the psychological impact on women who are told that their mammogram and ultrasound were inconclusive and that a biopsy is required to rule out cancer,” says Thomas Stavros, MD, a professor in the Department of Radiology at University of Texas Health Sciences Center and chief medical officer at Seno Medical, an imaging company. It’s commercializing a new modality called opto-acoustic imaging that combines laser light with ultrasound to show the radiologist function and anatomy features, which in turn can show tumor lesions that are present that ultrasound alone would not show. Seno’s product is in the pipeline seeking Food and Drug Administration approval.
"Conscientious clinicians rightly want to confirm that a mass is not malignant, so the guidelines and clinical practice aren't at fault,” Stavros adds. “It's simply that technology—as advanced as it has become—still needs further refinement to provide better specificity without sacrificing sensitivity and to engender increased diagnostic confidence for the clinician. There are significant volumes and costs of procedures required to reach a definitive, 'yes,' that breast cancer does or does not exist."
Artificial intelligence hasn’t yet gained a sizable foothold in radiology, but it’s starting to get some traction that Stavros expects to accelerate. Samsung recently released automated segmentation technology to outline the borders of a lesion, he notes. A radiologist can point to the center of a mass, and Samsung’s software will automatically outline the lesion so the radiologist can better determine its shape and orientation.