Optoacoustic Imaging Tool Effective in Differentiating Benign from Malignant Breast Masses
MELISSA SILVERBERG
August 01, 2018
Undergoing a breast biopsy to determine whether a mass detected during routine imaging is malignant or benign can be a stressful and expensive process for millions of women — especially considering that the vast majority of those biopsies come back negative.
But a new imaging technology can drastically improve diagnostics and reduce the number of false positives experienced by patients, according to new research published in Radiology, “A Pivotal Study of Optoacoustic Imaging to Diagnose Benign and Malignant Breast Masses.”
Seeking to improve on the specificity offered by current technology, researchers evaluated the effectiveness of an optoacoustic device in differentiating between benign and malignant masses. The investigational device generates real-time images of grayscale US with fused color-coded optoacoustic (OA) features of benign and malignant breast masses.
But a new imaging technology can drastically improve diagnostics and reduce the number of false positives experienced by patients, according to new research published in Radiology, “A Pivotal Study of Optoacoustic Imaging to Diagnose Benign and Malignant Breast Masses.”
Seeking to improve on the specificity offered by current technology, researchers evaluated the effectiveness of an optoacoustic device in differentiating between benign and malignant masses. The investigational device generates real-time images of grayscale US with fused color-coded optoacoustic (OA) features of benign and malignant breast masses.
Butler
Dogan
“Using current technology, we are not always able to differentiate between benign and malignant masses, and we do not want to miss a cancer, so a biopsy is necessary,” said study author Reni Butler, MD, an assistant professor of radiology and biomedical imaging at Yale School of Medicine, who served as co-principal investigator on the research. “So the question is, how do we distinguish between the two so we don’t have to biopsy as many masses? And if we can improve our ability to tell the difference, we can avoid that extra anxiety, cost and discomfort for women.”
The 16-site study of 2,105 women with breast masses took place over three years (2012-2015) at both private and academic medical centers. The study compared Breast Imaging Reporting and Data System (BI-RADS) categories assigned by seven experienced blinded independent readers to benign and malignant breast masses using OA data fused with grayscale ultrasound (OA/US) vs. US imaging alone.
“While there was a lot of data about optoacoustic imaging in a pre-clinical setting, a large scale clinical study like this did not exist,” said study author Basak Dogan, MD, an associate professor of radiology, a Eugene P. Frenkel Endowed Scholar in Clinical Medicine and director of breast imaging research at University of Texas Southwestern Medical Center. Dr. Dogan served as a site investigator for the study.
Optoacoustic imaging produces a grayscale image similar to conventional US, but also provides functional information about the amount of hemoglobin and degree of oxygenation of hemoglobin in and around breast masses, Dr. Butler said.
The technology, developed in part by Seno Medical Instruments, produces color maps that can help identify these elements in the image. For example, a mass that is slow growing and oxygenated would be color-coded green, while malignant masses that are growing more quickly or at varying rates, have abnormal vessel formation and are more deoxygenated would be color-coded red, she said.
“The two masses may look essentially identical on the grayscale image and have morphologic features that are very similar, but when you look at the optoacoustic color map, it’s clear that their tumor biology appears very different,” Dr. Butler said.
The study showed that using OA/US imaging resulted in a significant reduction of false positive assessment of breast masses. At a net reduction of 28.5 percent, more than a quarter of breast masses that would have been recommended for a biopsy could be downgraded, Dr. Butler said. The imaging specificity increased by 15 percent.
Dr. Dogan said she was pleasantly surprised with the results of the study and the potential for clinical application since reducing the number of benign biopsies women receive after US is an important goal. A suspicious, or false positive US assessment can cause significant patient anxiety. Furthermore, breast biopsy is a costly procedure that adds to the growing health care costs. OA/US can save significant costs by decreasing the number of unnecessary biopsies.
Another benefit: OA/US imaging does not use ionizing radiation or require a contrast injection.
These results are just a tipping point for new research already underway.
Drs. Dogan and Butler are working together on another study using OA-US technology to investigate the clinical and pathophysiological characteristics of breast cancer, and whether the technology can help predict which tumors will be more or less aggressive.
“Ideally, we hope that this technology will become available to radiologists who interpret breast imaging to help them significantly reduce benign biopsies and improve the diagnostic accuracy of what we do,” Dr. Butler said.
The 16-site study of 2,105 women with breast masses took place over three years (2012-2015) at both private and academic medical centers. The study compared Breast Imaging Reporting and Data System (BI-RADS) categories assigned by seven experienced blinded independent readers to benign and malignant breast masses using OA data fused with grayscale ultrasound (OA/US) vs. US imaging alone.
“While there was a lot of data about optoacoustic imaging in a pre-clinical setting, a large scale clinical study like this did not exist,” said study author Basak Dogan, MD, an associate professor of radiology, a Eugene P. Frenkel Endowed Scholar in Clinical Medicine and director of breast imaging research at University of Texas Southwestern Medical Center. Dr. Dogan served as a site investigator for the study.
Optoacoustic Imaging Offers Color-Coded View
Optoacoustic imaging produces a grayscale image similar to conventional US, but also provides functional information about the amount of hemoglobin and degree of oxygenation of hemoglobin in and around breast masses, Dr. Butler said.
The technology, developed in part by Seno Medical Instruments, produces color maps that can help identify these elements in the image. For example, a mass that is slow growing and oxygenated would be color-coded green, while malignant masses that are growing more quickly or at varying rates, have abnormal vessel formation and are more deoxygenated would be color-coded red, she said.
“The two masses may look essentially identical on the grayscale image and have morphologic features that are very similar, but when you look at the optoacoustic color map, it’s clear that their tumor biology appears very different,” Dr. Butler said.
The study showed that using OA/US imaging resulted in a significant reduction of false positive assessment of breast masses. At a net reduction of 28.5 percent, more than a quarter of breast masses that would have been recommended for a biopsy could be downgraded, Dr. Butler said. The imaging specificity increased by 15 percent.
A New Tool for Radiologists?
Dr. Dogan said she was pleasantly surprised with the results of the study and the potential for clinical application since reducing the number of benign biopsies women receive after US is an important goal. A suspicious, or false positive US assessment can cause significant patient anxiety. Furthermore, breast biopsy is a costly procedure that adds to the growing health care costs. OA/US can save significant costs by decreasing the number of unnecessary biopsies.
Another benefit: OA/US imaging does not use ionizing radiation or require a contrast injection.
These results are just a tipping point for new research already underway.
Drs. Dogan and Butler are working together on another study using OA-US technology to investigate the clinical and pathophysiological characteristics of breast cancer, and whether the technology can help predict which tumors will be more or less aggressive.
“Ideally, we hope that this technology will become available to radiologists who interpret breast imaging to help them significantly reduce benign biopsies and improve the diagnostic accuracy of what we do,” Dr. Butler said.