Understanding Breast Cancer Screening Options: Comparing Mammograms and QT Ultrasounds
- Dr. Salome Masghati, MD
- May 4
- 5 min read
As a physician who understands both the promise and the limitations of current breast cancer screening tools, I’ve been following the development of emerging technologies like QT ultrasound with interest. Mammography, while still the gold standard, has well-documented limitations—particularly in women with dense breast tissue. Other drawbacks are the breast tissue compression, discomfort, and the use of localized ionizing radiation.
Breast MRI is a powerful diagnostic tool, particularly valuable for high-risk patients and those with dense breast tissue. However, it is not without limitations. One notable concern is its variable sensitivity in detecting microcalcifications, which are often early indicators of ductal carcinoma in situ (DCIS). Studies have shown that the sensitivity of breast MRI for detecting cancers associated with microcalcifications can be relatively low, with some reports indicating a sensitivity of approximately 87% . This suggests that MRI may miss certain cancers that mammography could detect.
QT ultrasound has been proposed as a non-invasive, radiation-free alternative that could potentially address some of these challenges. However, after reviewing the company’s own published data, I believe it’s important to remain cautious.
Each method brings its own set of advantages and drawbacks. By understanding these differences, women can make better choices for their health.
What is a Mammogram?
A mammogram is a specialized X-ray designed to identify tumors or abnormalities in breast tissue. This procedure involves placing the breast between two plates to capture clear images.
2D Mammography vs. 3D Tomosynthesis: What's the Difference?
2D Mammography captures two flat images of the breast, providing a standard view for detecting abnormalities. However, overlapping tissues can sometimes obscure lesions, especially in women with dense breast tissue.
3D Tomosynthesis, or digital breast tomosynthesis (DBT), takes multiple X-ray images from different angles, creating a layered, three-dimensional view of the breast. This technique aims to reduce the overlap of tissues, potentially making it easier to detect cancers.
Detection Rates: Studies indicate that 3D tomosynthesis improves cancer detection rates compared to 2D mammography. For instance, a meta-analysis involving over two million patients found that combining DBT with 2D mammography increased cancer detection rates and reduced recall rates.
Mammography and Mortality: The Controversy
Despite advancements, debates persist about mammography's impact on breast cancer mortality:
Overdiagnosis: Some studies suggest that mammography can lead to overdiagnosis, identifying cancers that may not have caused harm if left undetected. Estimates of overdiagnosis associated with mammography have ranged from 1% to 54% .
Mortality Reduction: While breast cancer mortality has decreased over the past decades, it's challenging to attribute this solely to mammography. Improved treatments and increased awareness also play significant roles. A study in the New England Journal of Medicine indicated that the contribution of mammography to mortality reduction might be at the lower end of the estimated range .
Mammograms can serve two purposes: they may be performed as a routine screening for women without any symptoms or as a diagnostic tool for women who have specific concerns about their breast health.
What is QT Ultrasound?
QT Ultrasound is an exciting technology that utilizes sound waves to create detailed images of breast tissue. It’s safe, non-invasive, and may play a role in improving comfort and reducing unnecessary callbacks—especially in women with dense breasts, younger patients, or those with limited access to care. But based on its own published data, it’s not yet a proven alternative to mammography or MRI when it comes to detecting cancer.
A significant advantage of QT ultrasound is that it does not emit ionizing radiation. This aspect makes it a safer alternative for women who may be concerned about radiation exposure. For example, research indicates that QT ultrasounds are beneficial for approximately 40% of women with dense breasts, where mammograms alone may overlook cancerous areas.
The results showed that QT Ultrasound was better at detecting cysts and benign lesions than mammography. Radiologists had a 17% improvement in detecting cysts and a 68% reduction in unnecessary recalls for cysts when using QT. The study also found a 10% overall improvement in ROC-AUC (a measure of diagnostic accuracy) when readers used QT compared to mammography.
That sounds promising—but here’s the catch: these gains were not in detecting cancers. In fact, QT showed a slightly lower cancer recall rate and cancer detection rate than mammography, although the difference wasn’t statistically significant. This means QT didn’t perform better when it really counted.
The QT ultrasound was developed by Dr. John Klock, a physician and entrepreneur who also co-authored a recent study evaluating its performance: “An Exploratory Multi-reader, Multi-case Study Comparing Transmission Ultrasound to Mammography on Recall Rates and Detection Rates for Breast Cancer Lesions” (Malik B, Iuanow E, Klock J). The study, published by the company itself.
The results of that study showed that QT Ultrasound was better at detecting cysts and benign lesions than mammography. Radiologists had a 17% improvement in detecting cysts and a 68% reduction in unnecessary recalls for cysts when using QT. The study also found a 10% overall improvement in ROC-AUC (a measure of diagnostic accuracy) when readers used QT compared to mammography.
That sounds promising—but here’s the catch: these gains were not in detecting cancers. In fact, QT showed a slightly lower cancer recall rate and cancer detection rate than mammography, although the difference wasn’t statistically significant. This means QT didn’t perform better when it really counted.
Key Limitations to Be Aware Of
While this study helps shine light on the potential of QT, it's important to interpret the findings carefully:
The study was small and retrospective, with just 27–28 cancer cases—too small to draw firm conclusions.
Several cases were excluded due to technical issues or limitations in the QT scanner's field of view (especially near the chest wall and axilla), where cancers can be missed.
It didn't compare QT to 3D tomosynthesis or MRI, which are more advanced and widely used tools in many breast centers today.
Improvements were mainly seen in benign lesion detection, which might help reduce false positives but doesn’t prove QT improves cancer diagnosis.
Apparent Gains Driven by Benign Lesions: The statistically significant improvements seen in ROC-AUC and detection rates were primarily driven by better identification of benign lesions (particularly cysts), not cancers. This limits the clinical relevance of the findings in cancer screening or diagnosis.
No Improvement in Cancer Detection: QT did not demonstrate a statistically significant improvement in cancer recall rate, detection rate, or AUC compared to FFDM. In fact, cancer detection with QT was slightly lower across all metrics, with p-values > 0.05, indicating these differences could be due to chance.
The clinical setting wasn't replicated perfectly, as this was a reader study, not a real-time clinical use case. Reader studies often don’t reflect how radiologists perform in real-life patient care.
Who Should Choose What?
Choosing between a mammogram and QT ultrasound often hinges on personal risk factors and breast tissue density. Women with a family history of breast cancer or previously noted breast issues should consult their healthcare provider about the best screening options.
For women with dense breast tissue, a breast ultrasound performed by a professional Is a useful tool. This doesn't have to be a QT ultrasound which Is often associated with higher out of pocket costs than a regular breast ultrasound. However, that decision is often left to women themselves as insurance coverage often is a limitation.
Like any new tool, the QT ultrasound needs further validation. Larger, prospective studies—ideally independent of the company—are essential before QT can be recommended as a routine screening or diagnostic method. Until then, it may find a place as a complementary tool, but not a replacement.
Final Thoughts
Knowledge about the differences between mammograms and QT ultrasounds empowers women to make informed choices regarding their breast cancer screening options. Both methods are crucial for early detection, and understanding when to use each can lead to better health outcomes.
Regular screenings tailored to individual health needs are essential. Consulting with a healthcare professional can help determine the most appropriate screening method for each woman's circumstances. This proactive approach is vital in navigating important aspects of women's health.
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