This work was supported by the National Institutes of Health under grants P41-RR01192 (Laser Microbeam and Medical Program: LAMMP), U54-CA105480 (Network for Translational Research in Optical Imaging: NTROI), U54-CA136400, R01-CA142989, NCI-2P30CA62203 (University of California, Irvine Cancer Center Support Grant), NCI-T32CA009054 (University of California, Irvine Institutional Training Grant), Chancellor’s Club for Excellence Fellowship of University of California, Irvine, and Susan G. Komen for the Cure Postdoctoral Fellowship. BLI programmatic support from the Beckman Foundation and the Air Force Research Laboratory, under agreement number FA9550-04-1-0101 is acknowledged. The authors wish to thank Montana Compton and Amanda F. Durkin for their assistance as well as the patients who generously volunteered their time for this study. Conflict of interest statement: Bruce J. Tromberg and Albert E. Cerussi report patents, owned by the University of California, related to the technology and analysis methods described in this study. The DOSI instrumentation used in this study was constructed in a university laboratory using federal grant support (NIH). The University of California has licensed DOSI technology and analysis methods to two companies, FirstScan, Inc. and Volighten, Inc. for different fields of use, including breast cancer (FirstScan). This research was completed without participation, knowledge, or financial support of either company, and data were acquired and processed from patients by coauthors unaffiliated with either entity. The IRB and Conflict of Interest Office of the University of California, Irvine, have reviewed both patent and corporate disclosures and did not find any concerns.