title: Breast-conserving surgery after chemotherapy: value of MDCT for determining tumor distribution and shrinkage pattern.
abstract: OBJECTIVE
  For this study, we investigated the usefulness of MDCT in assessing the extent of residual breast cancer after neoadjuvant chemotherapy. To ensure the success of breast-conserving surgery, we evaluated the usefulness of determining the tumor distribution before neoadjuvant chemotherapy and the shrinkage pattern after neoadjuvant chemotherapy.
  
  
  METHODS
  MDCT before and after neoadjuvant chemotherapy was performed in 46 consecutive patients with 47 locally advanced breast cancers. The distribution pattern of contrast enhancement on MDCT before neoadjuvant chemotherapy was classified into five categories: solitary lesion, grouped lesion (localized lesion with linear, spotty, or linear and spotty enhancement), separated lesion (multiple foci of contrast enhancement), mixed lesion (grouped lesion with multiple foci), and replaced lesion (diffuse contrast enhancement in whole quadrants).
  
  
  RESULTS
  There was agreement between the MDCT assessment and pathologic findings in 44 (94%) of the 47 tumors. In the partial response group with nonreplaced lesions, MDCT revealed three shrinkage patterns: pattern 1a, concentric shrinkage without surrounding lesions; pattern 1b, concentric shrinkage with surrounding lesions; and pattern 2, shrinkage with residual multinodular lesions. Breast-conserving surgery was performed successfully in 14 patients including complete response cases that were detected on the basis of MDCT findings and partial response cases that were detected on the basis of observation of pattern 1 shrinkage. In all five patients with pattern 2 shrinkage, CT underestimated the residual tumor extent by more than 2 cm.
  
  
  CONCLUSIONS
  MDCT classification of tumor distribution before neoadjuvant chemotherapy and of shrinkage patterns after neoadjuvant chemotherapy is important in the preoperative evaluation of patients undergoing breast-conserving surgery.
authors.affiliation: Department of Radiology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan. tozaki@mtf.biglobe.ne.jp
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Tozaki
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Shinji
authors.initials: S
authors.lastname: Uno
authors.forename: Keisuke
authors.initials: K
authors.lastname: Aiba
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takeyama
authors.forename: Hisashi
authors.initials: H
authors.lastname: Shioya
authors.forename: Isao
authors.initials: I
authors.lastname: Tabei
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Toriumi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Fukuda
mesh_terms: D000328:Adult; D000368:Aged; D018943:Anthracyclines / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000601:surgery; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging* / Q000601:surgery; D043823:Taxoids / Q000008:administration & dosage; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D018943:Anthracyclines; D043823:Taxoids