[Intl_DxMedPhys] Effective Dose of Dedicated Breast CT

[Brandon Nelson]

Hi Liqiang,

I’ve tagged my colleague Sunny (ccd), our resident breast CT expert, and
she gave a great answer which I’ll copy below.

Best wishes! Brandon

Hi Brandon,



I am not sure about effective dose but I believe the standard way to
compute mean glandular dose (MGD) for breast CT is using air kerma and DgN
coefficients. Eq 2 of this paper describes it:

S. Vedantham, L. Shi, A. Karellas, A. M. O’Connell, and D. L. Conover,
“Personalized estimates of radiation dose from dedicated breast CT in a
diagnostic population and comparison with diagnostic mammography,” *Phys.
Med. Biol.*, vol. 58, no. 22, pp. 7921–7936, Nov. 2013, doi:
10.1088/0031-9155/58/22/7921 <https://urldefense.com/v3/__https://doi.org/10.1088/0031-9155/58/22/7921__;!!KGKeukY!0XTEWqt8akBtkNRBp1AxyHV1cL774IMzCsV1me-DiYaQKdR4HXRsmE5jacbzK8yD_k6ayFAiTEYdWgVo2beg_XmzkR4Yy5l4uEtOBdM$ >.



For DgN coefficients, I believe Andrew Hernandez’ method deriving them
using patient-derived breast shapes and heterogeneous fibroglandular
distributions is most accurate:

A. M. Hernandez, A. E. Becker, and J. M. Boone, “Updated breast CT dose
coefficients (Dg N CT ) using patient‐derived breast shapes and
heterogeneous fibroglandular distributions,”*Medical Physics*, vol. 46, no.
3, pp. 1455–1466, Mar. 2019, doi: 10.1002/mp.13391
<https://urldefense.com/v3/__https://doi.org/10.1002/mp.13391__;!!KGKeukY!0XTEWqt8akBtkNRBp1AxyHV1cL774IMzCsV1me-DiYaQKdR4HXRsmE5jacbzK8yD_k6ayFAiTEYdWgVo2beg_XmzkR4Yy5l4x7HvvNA$ >.



Also, DIDSR recently released an RST to help with breast CT dosage
calculation: PyBDC: Python Breast Dosage Calculator | Center for Devices
and Radiological Health
<https://urldefense.com/v3/__https://cdrh-rst.fda.gov/pybdc-python-breast-dosage-calculator__;!!KGKeukY!0XTEWqt8akBtkNRBp1AxyHV1cL774IMzCsV1me-DiYaQKdR4HXRsmE5jacbzK8yD_k6ayFAiTEYdWgVo2beg_XmzkR4Yy5l4cZQlvUs$ >. This is
Harsha’s work – shoutout to him!



I wonder if your colleague is referring to breast CT dose computation using
monte-carlo simulation, which is probably more accurate for
patient-specific dose. This has been done in the literature too, for
example:

F. Di Franco *et al.*, “GEANT4 Monte Carlo simulations for virtual clinical
trials in breast X-ray imaging: Proof of concept,” *Physica Medica*, vol.
74, pp. 133–142, Jun. 2020, doi: 10.1016/j.ejmp.2020.05.007
<https://urldefense.com/v3/__https://doi.org/10.1016/j.ejmp.2020.05.007__;!!KGKeukY!0XTEWqt8akBtkNRBp1AxyHV1cL774IMzCsV1me-DiYaQKdR4HXRsmE5jacbzK8yD_k6ayFAiTEYdWgVo2beg_XmzkR4Yy5l43r8AwwQ$ >.



Hope this helps,

Sunny





Su Hyun (Sunny) Lyu, Ph.D.

*ORISE Fellow*

Division of Imaging, Diagnostics, and Software Reliability

Office of Science and Engineering Laboratories

Center for Devices and Radiological Health

U.S. Food and Drug Administration

*suhyun.lyu at fda.hhs.gov <suhyun.lyu at fda.hhs.gov>*


On Fri, Sep 26, 2025 at 5:02 PM Liqiang Ren via Intl_dxmedphys_wd_osu_list <
intl_dxmedphys_wd_osu_list at lists.osu.edu> wrote:

> Hi All, I've been trying to find papers that talk about the effective dose
> from dedicated breast cone-beam CT scanners, but haven’t had much luck. If
> you know of any, I’d really appreciate it if you could share them! Thanks,
> Liqiang
>
> Hi All,
>
>
>
> I've been trying to find papers that talk about the effective dose from
> dedicated breast cone-beam CT scanners, but haven’t had much luck. If you
> know of any, I’d really appreciate it if you could share them!
>
>
>
> Thanks,
>
>
>
> Liqiang
>
> ------------------------------
>
> UT Southwestern
>
> Medical Center
>
> The future of medicine, today.
>
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