title: Ultrasound is at least as good as magnetic resonance imaging in predicting tumour size post-neoadjuvant chemotherapy in breast cancer.
abstract: BACKGROUND
  The aim of this study was to evaluate the accuracy of clinical imaging of the primary breast tumour post-neoadjuvant chemotherapy (NAC) related to the post-neoadjuvant histological tumour size (gold standard) and whether this varies with breast cancer subtype. In this study, results of both magnetic resonance imaging (MRI) and ultrasound (US) were reported.
  
  
  METHODS
  Patients with invasive breast cancer were enrolled in the INTENS study between 2006 and 2009. We included 182 patients, of whom data were available for post-NAC MRI (n=155), US (n=123), and histopathological tumour size.
  
  
  RESULTS
  MRI estimated residual tumour size with <10-mm discordance in 54% of patients, overestimated size in 28% and underestimated size in 18% of patients. With US, this was 63%, 20% and 17%, respectively. The negative predictive value in hormone receptor-positive tumours for both MRI and US was low, 26% and 33%, respectively. The median deviation in clinical tumour size as percentage of pathological tumour was 63% (P25=26, P75=100) and 49% (P25=22, P75=100) for MRI and US, respectively (P=0.06).
  
  
  CONCLUSIONS
  In this study, US was at least as good as breast MRI in providing information on residual tumour size post-neoadjuvant chemotherapy. However, both modalities suffered from a substantial percentage of over- and underestimation of tumour size and in addition both showed a low negative predictive value of pathologic complete remission (Gov nr: NCT00314977).
authors.affiliation: Department of Medical Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Birgit E P J
authors.initials: BE
authors.lastname: Vriens
authors.affiliation: Department of Pathology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Bart
authors.initials: B
authors.lastname: de Vries
authors.affiliation: Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Marc B I
authors.initials: MB
authors.lastname: Lobbes
authors.affiliation: Comprehensive Cancer Center the Netherlands, Nijmegen, The Netherlands.
authors.forename: Saskia M
authors.initials: SM
authors.lastname: van Gastel
authors.affiliation: Department of Internal Medicine, Atrium Medical Center, Heerlen, The Netherlands.
authors.forename: Franchette W P J
authors.initials: FW
authors.lastname: van den Berkmortel
authors.affiliation: Department of Internal Medicine, Jeroen Bosch Hospital, 's Hertogenbosch, The Netherlands.
authors.forename: Tineke J
authors.initials: TJ
authors.lastname: Smilde
authors.affiliation: Department of Internal Medicine, Catharina-Hospital, Eindhoven, The Netherlands.
authors.forename: Laurence J C
authors.initials: LJ
authors.lastname: van Warmerdam
authors.affiliation: Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Maaike
authors.initials: M
authors.lastname: de Boer
authors.affiliation: Department of Internal Medicine, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.
authors.forename: Dick Johan
authors.initials: DJ
authors.lastname: van Spronsen
authors.affiliation: Department of Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Marjolein L
authors.initials: ML
authors.lastname: Smidt
authors.affiliation: Biostatistics, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.
authors.forename: Petronella G M
authors.initials: PG
authors.lastname: Peer
authors.affiliation: Department of Medical Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Maureen J
authors.initials: MJ
authors.lastname: Aarts
authors.affiliation: Department of Medical Oncology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands. Electronic address: vcg.tjan.heijnen@mumc.nl.
authors.forename: Vivianne C G
authors.initials: VC
authors.lastname: Tjan-Heijnen
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D020360:Neoadjuvant Therapy; D009426:Netherlands; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D016896:Treatment Outcome; D047368:Tumor Burden / Q000187:drug effects*; D016217:Ultrasonography, Mammary
keywords: Breast cancer; Magnetic resonance imaging (MRI); Neoadjuvant chemotherapy; Ultrasound (US)