Researchers at the University of California (UC), Davis, have constructed a dedicated breast PET/CT scanner that can accurately visualize suspected lesions in three dimensions.
Spencer L. Bowen, MD, of UC Davis’s department of biochemical engineering, and colleagues reported their findings in this month's Journal of Nuclear Medicine.
A clinical trial is currently being conducted with a dedicated breast scanner (DbPET/CT) involving women who are highly suspected of having breast cancer. Seven breasts from four patients have been imaged. The investigators found that scanning of the uncompressed breast with DbPET/CT can produce 3D images that accurately show the size, extent and location of biopsy-confirmed breast cancer.
In one patient, a DbPET/CT scanner, compared with a commercial whole body PET/CT scanner, demonstrated qualitatively improved visualization of ductal carcinoma in situ (DCIS).
The researchers said that the increased resolution of the dedicated scanner for both the PET and CT “results in an appreciable improvement in lesion visualization for a patient who was scanned with typical clinical acquisition protocol."
The CT component of DbPET/CT, compared with breast PET alone, also increases system functionality, the authors wrote. For example, in one patient, a combination of increased radiograph density with 18F-FDG uptake or iodine contrast accurately localized a suspected lesion that was originally hidden on screening mammography. The CT component could also improve the utility of robotic biopsy devices and fused 3D DbPET/CT images could allow for accurate needle placement.
Bowen and colleagues found some limitations on patient imaging with the DbPET/CT. Imaging of the chest wall and breast axillary tail coverage in both modalities is restricted because of the constraints associated with prone imaging. Also, DbPET/CT is not yet able to produce fully quantitative images and “[a]ccurate quantification is likely to be important when using breast PET to monitor therapy response, and efforts to achieve such are ongoing.”
In conclusion, the researchers said that the preliminary clinical results demonstrate that dedicated tomographic scanning of the breast can accurately visualize lesions in three dimensions and that more research “is required to determine whether dedicated breast PET/CT has a useful role in the clinical management of patients with primary breast cancer.”