Aims and objectives
Mammographic screening is associated with a substantial and significant reduction in breast cancer mortality [1].
However,
the breast is a highly radiation-sensitive organ,
and although low,
the risk of a radiation-induced cancer is concerning to many women,
and can adversely affect adherence to screening programs [2].
For routine screening,
it is therefore important that x-ray dose is kept as low as possible without compromising on image quality or the ability to detect cancers.
To keep patient doses at a minimum,
accurate calculations for monitoring and...
Methods and materials
Raw digital mammograms from 102 women with a wide-range of breast densities with standard four-view temporal mammograms were analyzed (i.e.
left and right craniocaudal and mediolateral oblique views).
96 women were imaged one year apart on GE Healthcare (GE) or Hologic Selenia (Hologic) x-ray systems and 6 women were imaged over several years on a mix of GE,
Hologic and Siemens Novation systems.
All images were run through automated breast density assessment software (VolparaDensity™),
to obtain the volumetric breast density (VBD),
breast volume (BV) and,...
Results
Manufacturer & Patient-Specific Dose Comparison
Patient-specific MGD estimates per view (Figure 2) were highly correlated with the GE- and Hologic-reported doses (PCC’s = 0.916 and 0.879,
respectively).
However,
the overall average MGD per view for reported and patient-specific estimates were significantly different: 2.04 and 2.27 for GE,
respectively,
and 1.90 and 2.21 for Hologic,
respectively (Figure 3).
Compared to patient-specific estimates,
GE and Hologic tended to underestimate MGD,
more so in dense and fattier breasts respectively (Figure 4).
Dose Comparison Over Time
Both the reported...
Conclusion
The results presented here indicate that the patient-specific estimates of MGD,
which incorporate the individual glandularities of the women and use a standard dose algorithm,
differ from,
but correlate well with the reported doses from GE and Hologic systems.
These patient-specific estimates of MGD could be used to help standardize dose monitoring for patients undergoing routine screening on different x-ray systems.
Personal information
Chris Tromans,
PhD,
Matakina Technology Ltd,
Wellington,
NZ;
[email protected]
Ariane Chan,
PhD,
Matakina Technology Ltd,
Wellington,
NZ;
[email protected]
Ralph Highnam,
PhD,
Matakina Technology Ltd,
Wellington,
NZ;
[email protected]
References
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[3] Porras-Chaverri et al.
in 55th Annual Meeting of the American Association of Physicists in Medicine.
2013
[4] Patel et al.
in 55th Annual Meeting of the American Association of Physicists in Medicine.
2013; Oral Presentation
[5] Hendrick et al.
Am J Roentgenol.
2010; 194: 362-369
[6] Dance et al.
Phys Med Biol.
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[7] Dance et al.
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[8]...