We have developed ultrasound (US)-guided diffuse optical tomography (DOT) technique to assist US diagnosis of
breast cancer and to predict neoadjuvant chemotherapy response of breast cancer patients. The technique was
implemented using a hand-held hybrid probe consisting co-registered US transducer and optical source and detector
fibers which couple the light illumination from laser diodes and photon detection to PMT detectors. With the US
guidance, diffused light measurements were made at the breast lesion site and the normal contralateral reference site
which was used to estimate the background tissue optical properties for imaging reconstruction. However, background
optical properties were affected by the chest wall underneath the breast tissue. In this study, we have analyzed data
from 297 female patients and results have shown statistical significant correlation between fitted optical properties (μa
and μs’) and the chest wall depth detected by a boundary detection algorithm applied to co-registered US images (r <
0.27, p < 1.0 x 10-4). After subtracting the background total hemoglobin (tHb) computed with μa at each wavelength,
the difference between malignant and benign lesion groups has improved. The Area-under-the- ROC curve (AUC)
has improved from 88.5% to 91.5% (sensitivity improved from 85.0% to 87.5% and specificity from 90.2% to 92.6%).
Statistical test has revealed significant difference of the AUC improvements after subtracting background tHb values.
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