Breast tomosynthesis: Accuracy of tumor measurement compared with digital mammography and ultrasonography.
BACKGROUND
Mammographic tumor size measurement can be difficult because breast structures are superimposed onto a two-dimensional (2D) plane, potentially obscuring the tumor outline. Breast tomosynthesis (BT) is a 3D X-ray imaging technique in which low-dose images are acquired over a limited angular range at a total dose comparable to digital mammography (DM). These low-dose images are used to mathematically reconstruct a 3D image volume of the breast, thus reducing the problem of superimposed tissue.


OBJECTIVE
To investigate whether breast cancer size can be more accurately assessed with breast tomosynthesis than with digital mammography and ultrasonography (US), by reducing the disturbance effect of the projected anatomy.


METHODS
A prototype BT system was used. The main inclusion criterion for BT examination was subtle but suspicious findings of breast cancer on 2D mammography. Sixty-two women with 73 breast cancers were included. BT, DM, and US sizes were measured independently by experienced radiologists without knowledge of the pathology results, which were used as reference.


RESULTS
The tumor outline could be determined in significantly more cases with BT (63) and US (60) than DM (49). BT and US size correlated well with pathology (R=0.86 and R=0.85, respectively), and significantly better than DM size (R=0.71). Accordingly, staging was significantly more accurate with BT than with DM.


CONCLUSIONS
The study indicates that BT is superior to DM in the assessment of breast tumor size and stage.
Förnvik
Daniel
D
Department of Medical Radiation Physics, Lund University, Malmö University Hospital, Malmö, Sweden. daniel.fornvik@med.lu.se
Zackrisson
Sophia
S
Ljungberg
Otto
O
Svahn
Tony
T
Timberg
Pontus
P
Tingberg
Anders
A
Andersson
Ingvar
I
D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D014463:Ultrasonography