Positron Emission Mammography Valuable For Breast Cancer Detection
Posted Nov 29 2010 11:12am
Magnetic resonance imaging (MRI) has become an important part of breast cancer screening, particularly in women at high risk for breast cancer. This is because MRI has been shown to be highly sensitive at detecting breast lesions , which has resulted in improved rates of breast cancer survival. The drawback with MRI is that it has been reported to have a fairly high rate of false positive tests, which can lead to unnecessary breast biopsies.
Positron emmission mammography (PEM) is a relatively new breast cancer screening technology where a glucose-based tracer is used to detect breast cancer cells at a stage where they are often not detectable by other methods like mammagraphy or ultrasound. Since breast cancer cells have a high metabolic activity, they take up this tracer in higher amounts than surrounding cells and can then be easily visualized with a positron emmision scanner.
A new breast cancer study compared PEM to MRI in 388 women newly diagnosed with breast cancer. The breast cancer patients underwent both MRI and PEM in a randomized order and the performance of the two methods was compared. During the breast cancer screenings, 82 additional cancers were detected. A comparison of the performance of these two breast cancer screening methods showed:
34% of these additional breast cancers (28 of 82) were detected by both PEM and MRI when used as separate screening tests. Another 26% were detected by MRI alone, 17% by PEM alone, and 8.5% by mammography plus ultrasound.
When integrating PEM and MRI screening methods, 74% of these new breast cancers were detected in comparison to 60% detection using MRI alone.
When examining the other 306 breast cancer patients, PEM correctly diagnosed breast cancer in 91% of the cases compared to 86% correctly diagnosed with MRI.
PEM more accurately detected cancerous breast tumors (66%) compared to MRI (53%).
Of the 56 women requiring mastectomy, 71% were identified with MRI, while only 36% were identified with PEM.
The results of this study comparing the effectiveness of PEM and MRI suggest that PEM can be an important, viable breast cancer screening tool for many women. While PEM and MRI breast cancer screening detected the incidence of breast cancer at a similar rate with MRI being slightly better, combining the two methods appeared to improve breast cancer detection over either method used alone. Additionally, PEM showed a greater ability to accurately predict whether a breast tumor was benign or cancerous. This is an important finding because it could lead to a reduction in the number of unnecessary breast biopsies done every year. Since PEM appears to offer comparable results to MRI overall, PEM offers a viable alternative to women who can not tolerate or are not eligible for MRI breast cancer screenings. Used in combination, PEM and MRI appear to offer both a greater ability to detect breast cancer and a more accurate way to determine if a breast lesion is cancerous or not. This could result in an improvement in overall outcomes.