title: Microwave imaging for neoadjuvant chemotherapy monitoring: initial clinical experience.
abstract: BACKGROUND
  Microwave tomography recovers images of tissue dielectric properties, which appear to be specific for breast cancer, with low-cost technology that does not present an exposure risk, suggesting the modality may be a good candidate for monitoring neoadjuvant chemotherapy.
  
  
  METHODS
  Eight patients undergoing neoadjuvant chemotherapy for locally advanced breast cancer were imaged longitudinally five to eight times during the course of treatment. At the start of therapy, regions of interest (ROIs) were identified from contrast-enhanced magnetic resonance imaging studies. During subsequent microwave examinations, subjects were positioned with their breasts pendant in a coupling fluid and surrounded by an immersed antenna array. Microwave property values were extracted from the ROIs through an automated procedure and statistical analyses were performed to assess short term (30 days) and longer term (four to six months) dielectric property changes.
  
  
  RESULTS
  Two patient cases (one complete and one partial response) are presented in detail and demonstrate changes in microwave properties commensurate with the degree of treatment response observed pathologically. Normalized mean conductivity in ROIs from patients with complete pathological responses was significantly different from that of partial responders (P value = 0.004). In addition, the normalized conductivity measure also correlated well with complete pathological response at 30 days (P value = 0.002).
  
  
  CONCLUSIONS
  These preliminary findings suggest that both early and late conductivity property changes correlate well with overall treatment response to neoadjuvant therapy in locally advanced breast cancer. This result is consistent with earlier clinical outcomes that lesion conductivity is specific to differentiating breast cancer from benign lesions and normal tissue.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Meaney
authors.forename: Peter A
authors.initials: PA
authors.lastname: Kaufman
authors.forename: Lori S
authors.initials: LS
authors.lastname: Muffly
authors.forename: Michael
authors.initials: M
authors.lastname: Click
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Poplack
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Wells
authors.forename: Gary N
authors.initials: GN
authors.lastname: Schwartz
authors.forename: Roberta M
authors.initials: RM
authors.lastname: di Florio-Alexander
authors.forename: Tor D
authors.initials: TD
authors.lastname: Tosteson
authors.forename: Zhongze
authors.initials: Z
authors.lastname: Li
authors.forename: Shireen D
authors.initials: SD
authors.lastname: Geimer
authors.forename: Margaret W
authors.initials: MW
authors.lastname: Fanning
authors.forename: Tian
authors.initials: T
authors.lastname: Zhou
authors.forename: Neil R
authors.initials: NR
authors.lastname: Epstein
authors.forename: Keith D
authors.initials: KD
authors.lastname: Paulsen
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000556:secondary*; D018275:Carcinoma, Lobular / Q000188:drug therapy / Q000556:secondary*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008872:Microwaves; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010865:Pilot Projects; D011379:Prognosis