title: [Rectal cancer - local staging and imaging under neoadjuvant therapy].
abstract: OBJECTIVE
  Rectal cancer restaging after neoadjuvant therapy is based on two principles: an anatomic definition of the tumor allowing surgical planning and prognostic stage grouping.
  
  
  METHODS
  Emerging data suggest that reassessment using a combination of different imaging modalities may help to provide valuable prognostic information before definitive surgery.
  
  
  METHODS
  Perfusion computed tomography (CT) may provide special information regarding tumor vascularity.
  
  
  METHODS
  Evaluation of therapy response, especially of the circumferential resection margin (CRM) is necessary for surgical planning.
  
  
  RESULTS
  For local staging high-resolution and diffusion-weighted magnetic resonance imaging has proven to be of high diagnostic accuracy.
  
  
  CONCLUSIONS
  The M status should be assessed using multidetector computed tomography (MDCT) according to response evaluation criteria in solid tumors (RECIST) while lymph node evaluation requires either magnetic resonance imaging or positron emission tomography/computed tomography scanning.
authors.affiliation: Institut für Klinische Radiologie, Klinikum der Ludwig-Maximilians-Universität München, Campus Großhadern, Marchioninistr. 15, 81377, München, Deutschland. Martina.Karpitschka@med.uni-muenchen.de
authors.forename: M
authors.initials: M
authors.lastname: Karpitschka
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology* / Q000628:therapy*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome