The investigators propose to validate the utility of their novel hybrid imaging technique for accurate diagnosis of breast lesions, and for assessing chemotherapy response of cancer treatment and predicting treatment efficacy. The investigators' unique hybrid technique is implemented by simultaneously deploying near infrared (NIR) optical sensors and a commercial ultrasound (US) transducer mounted on a hand-held probe, and utilizing co-registered lesion structure information provided by ultrasound to improve the optical tomography.

As a result, the optical tomography assisted with US has overcome problems associated with intense light scattering and has provided reliable tumor angiogenesis distributions. Initial results with a small group of patients who underwent biopsy have shown that early stage invasive cancers present two-fold greater total hemoglobin concentration on average than fibroadenomas and other benign lesions. Initial results of advanced cancers have shown that the angiogenesis distribution is highly distorted and heterogeneous, and the distorted distributions correlate with histological microvessel density counts and can be used to assess chemotherapy response.

The objective of this study is to validate the investigators' initial results that NIR light guided by ultrasound can improve breast cancer diagnosis and monitor chemotherapy response.

Specific objectives of the study are:

Objective 1: Validate the sensitivity, specificity, positive predictive value and negative predictive value of optical tomography/US for distinguishing benign and early stage malignant breast tumors. Approximately 300 patients who will undergo ultrasound-guided biopsy are being recruited to this study from the University of Connecticut Health Center and Hartford Hospital. The total hemoglobin concentration and blood oxygen saturation will be the measured indices and the biopsy results will be used as the 'gold' standard.

Objective 2: Perform pilot studies of optical tomography/US to assess chemotherapy response and evaluate treatment efficacy. Patients diagnosed with locally advanced breast cancers (size greater than 3 cm) who will undergo chemotherapy will be enrolled to this study. Approximately, 20 to 30 patients are being recruited to the study from the University of Connecticut Health Center and Hartford Hospital.

Inclusion Criteria:

• Women undergoing ultrasound guided biopsy or breast cancer patients undergoing neoadjuvant thermotherapy treatment

Exclusion Criteria:

• Women under 18 years old.

1. Women undergo ultrasound guided biopsy
2. Breast cancer patients undergo neoadjuvant thermotherapy treatment