title: Dedicated Breast CT: Feasibility for Monitoring Neoadjuvant Chemotherapy Treatment.
abstract: OBJECTIVE
  In this prospective pilot study, the feasibility of non-contrast dedicated breast computed tomography (bCT) to determine primary tumor volume and monitor its changes during neoadjuvant chemotherapy (NAC) treatment was investigated.
  
  
  METHODS
  Eleven women who underwent NAC were imaged with a clinical prototype dedicated bCT system at three time points - pre-, mid-, and post-treatment. The study radiologist marked the boundary of the primary tumor from which the tumor volume was quantified. An automated algorithm was developed to quantify the primary tumor volume for comparison with radiologist's segmentation. The correlation between pre-treatment tumor volumes from bCT and MRI, and the correlation and concordance in tumor size between post-treatment bCT and pathology were determined.
  
  
  RESULTS
  Tumor volumes from automated and radiologist's segmentations were correlated (Pearson's r = 0.935, P < 0.001) and were not different over all time points [P = 0.808, repeated measures analysis of variance (ANOVA)]. Pre-treatment tumor volumes from MRI and bCT were correlated (r = 0.905, P < 0.001). Tumor size from post-treatment bCT was correlated with pathology (r = 0.987, P = 0.002) for invasive ductal carcinoma larger than 5 mm and the maximum difference in tumor size was 0.57 cm. The presence of biopsy clip (3 mm) limited the ability to accurately measure tumors smaller than 5 mm. All study participants were pathologically assessed to be responders, with three subjects experiencing complete pathologic response for invasive cancer and the reminder experiencing partial response. Compared to pre-treatment tumor volume, there was a statistically significant (P = 0.0003, paired t-test) reduction in tumor volume at mid-treatment observed with bCT, with an average tumor volume reduction of 47%.
  
  
  CONCLUSIONS
  This pilot study suggests that dedicated non-contrast bCT has the potential to serve as an expedient imaging tool for monitoring tumor volume changes during NAC. Larger studies are needed in future.
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Vedantham
authors.affiliation: Department of Imaging Sciences, University of Rochester Medical Center, Rochester, New York, USA.
authors.forename: Avice M
authors.initials: AM
authors.lastname: O'Connell
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Linxi
authors.initials: L
authors.lastname: Shi
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Karellas
authors.affiliation: Department of Medicine, Divisions of Hematology/Oncology, University of Rochester Medical Center, Rochester, New York, USA.
authors.forename: Alissa J
authors.initials: AJ
authors.lastname: Huston
authors.affiliation: Department of Surgery, University of Rochester Medical Center, Rochester, New York, USA.
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Skinner
keywords: Breast; dedicated breast CT; neoadjuvant chemotherapy; tomography; tumor size