title: Longitudinal optical monitoring of blood flow in breast tumors during neoadjuvant chemotherapy.
abstract: We measure tissue blood flow markers in breast tumors during neoadjuvant chemotherapy and investigate their correlation to pathologic complete response in a pilot longitudinal patient study (n  =  4). Tumor blood flow is quantified optically by diffuse correlation spectroscopy (DCS), and tissue optical properties, blood oxygen saturation, and total hemoglobin concentration are derived from concurrent diffuse optical spectroscopic imaging (DOSI). The study represents the first longitudinal DCS measurement of neoadjuvant chemotherapy in humans over the entire course of treatment; it therefore offers a first correlation between DCS flow indices and pathologic complete response. The use of absolute optical properties measured by DOSI facilitates significant improvement of DCS blood flow calculation, which typically assumes optical properties based on literature values. Additionally, the combination of the DCS blood flow index and the tissue oxygen saturation from DOSI permits investigation of tissue oxygen metabolism. Pilot results from four patients suggest that lower blood flow in the lesion-bearing breast is correlated with pathologic complete response. Both absolute lesion blood flow and lesion flow relative to the contralateral breast exhibit potential for characterization of pathological response. This initial demonstration of the combined optical approach for chemotherapy monitoring provides incentive for more comprehensive studies in the future and can help power those investigations.
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania, 209 S 33rd St, Philadelphia, PA 19104, United States of America.
authors.forename: J M
authors.initials: JM
authors.lastname: Cochran
authors.forename: S H
authors.initials: SH
authors.lastname: Chung
authors.forename: A
authors.initials: A
authors.lastname: Leproux
authors.forename: W B
authors.initials: WB
authors.lastname: Baker
authors.forename: D R
authors.initials: DR
authors.lastname: Busch
authors.forename: A M
authors.initials: AM
authors.lastname: DeMichele
authors.forename: J
authors.initials: J
authors.lastname: Tchou
authors.forename: B J
authors.initials: BJ
authors.lastname: Tromberg
authors.forename: A G
authors.initials: AG
authors.lastname: Yodh
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D061848:Optical Imaging; D010100:Oxygen / Q000378:metabolism; D013057:Spectrum Analysis
chemical_list: D010100:Oxygen