title: Optical mammography using diffuse optical spectroscopy for monitoring tumor response to neoadjuvant chemotherapy in women with locally advanced breast cancer.
abstract: OBJECTIVE
  Diffuse optical spectroscopy (DOS) has the potential to enable monitoring of tumor response during chemotherapy, particularly in the early stages of treatment. This study aims to assess feasibility of DOS for monitoring treatment response in HER2-negative breast cancer patients receiving neoadjuvant chemotherapy (NAC) and compare DOS with tumor response assessment by MRI.
  
  
  METHODS
  Patients received NAC in six cycles of 3 weeks. In addition to standard treatment monitoring by dynamic contrast enhanced MRI (DCE-MRI), DOS scans were acquired after the first, third, and last cycle of chemotherapy. The primary goal was to assess feasibility of DOS for early assessment of tumor response. The predictive value of DOS and DCE-MRI compared with pathologic response was assessed.
  
  
  RESULTS
  Of the 22 patients, 18 patients had a partial or complete tumor response at pathologic examination, whereas 4 patients were nonresponders. As early as after the first chemotherapy cycle, a significant difference between responders and nonresponders was found using DOS (HbO2 86% ± 25 vs. 136% ± 25, P = 0.023). The differences between responders and nonresponders continued during treatment (halfway treatment, HbO2 68% ± 22 vs. 110% ± 10, P = 0.010). Using DCE-MRI, a difference between responders and nonresponders was found halfway treatment (P = 0.005) using tumor volume measurement calculations.
  
  
  CONCLUSIONS
  DOS allows for tumor response assessment and is able to differentiate between responders and nonresponders after the first chemotherapy cycle and halfway treatment. In this study, DOS was equally effective in predicting tumor response halfway treatment compared with DCE-MRI. Therefore, DOS may be used as a novel imaging modality for (early) treatment monitoring of NAC.
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Boudewijn E
authors.initials: BE
authors.lastname: Schaafsma
authors.affiliation: Division of Image Processing, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: van de Giessen
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands. Department of Clinical Oncology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Ayoub
authors.initials: A
authors.lastname: Charehbili
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Vincent T H B M
authors.initials: VT
authors.lastname: Smit
authors.affiliation: Department of Clinical Oncology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Judith R
authors.initials: JR
authors.lastname: Kroep
authors.affiliation: Division of Image Processing, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Boudewijn P F
authors.initials: BP
authors.lastname: Lelieveldt
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Gerrit-Jan
authors.initials: GJ
authors.lastname: Liefers
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands. Percuros B.V., Enschede, the Netherlands.
authors.forename: Alan
authors.initials: A
authors.lastname: Chan
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Clemens W G M
authors.initials: CW
authors.lastname: Löwik
authors.affiliation: Division of Image Processing, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Jouke
authors.initials: J
authors.lastname: Dijkstra
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Cornelis J H
authors.initials: CJ
authors.lastname: van de Velde
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Martin N J M
authors.initials: MN
authors.lastname: Wasser
authors.affiliation: Department of Surgery, Leiden University Medical Center, Leiden, the Netherlands. a.l.vahrmeijer@lumc.nl.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Vahrmeijer
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods; D008327:Mammography / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012372:ROC Curve; D012307:Risk Factors; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D003287:Contrast Media