title: Relative Value of Restaging MRI, CT, and FDG-PET Scan After Preoperative Chemoradiation for Rectal Cancer.
abstract: BACKGROUND
  Management of rectal cancer has become multidisciplinary and is driven by the stage of the disease, with increased focus on restaging rectal cancer after neoadjuvant therapy.
  
  
  OBJECTIVE
  The purpose of this study was to assess the relative impact of restaging after preoperative chemoradiation with FDG-PET scan, CT, and MRI in the management of patients with rectal cancer.
  
  
  METHODS
  This was a retrospective study from a single institution.
  
  
  METHODS
  This study was conducted at a tertiary cancer center.
  
  
  METHODS
  A total of 199 patients met the inclusion criteria: patients with rectal adenocarcinoma; staged with positron emission tomography, CT, and MRI; T2 to T4, N0 to N2, M0 to M1; treated with neoadjuvant chemoradiation 50.4 Gy and infusional 5-fluorouracil; and restaged 4 weeks after chemoradiation before surgery between 2003 and 2013.
  
  
  METHODS
  Comparisons of the tumor stage among different imaging modalities before and after neoadjuvant chemoradiation were performed. The impact of restaging on the management plan was assessed.
  
  
  RESULTS
  The stage at presentation was T2, 8.04%; T3, 65.33%; T4, 26.63%; N0, 17.09%; N1, 47.74%; N2, 34.67%; M0, 81.91%; and M1, 18.09%. Changes in disease stage postneoadjuvant chemoradiation were observed in 99 patients (50%). The management plans of 29 patients (15%) were changed. The impact of each restaging modality on management for all of the patients was positron emission tomography, 11%; CT, 4%; and MRI, 4%. In patients with metastatic disease at primary staging, the relative impact of each restaging modality in changing management was positron emission tomography, 32%; CT, 18%; and MRI, 6%.
  
  
  CONCLUSIONS
  This study was limited by its single-center and retrospective design. Operations were performed 4 weeks after restaging.
  
  
  CONCLUSIONS
  Changes in the extent of disease after long-course chemoradiotherapy result in changes of management in a significant percentage of patients. Positron emission tomography has the most significant impact in the change of management overall, and its use in restaging advanced rectal cancer should be further explored.
authors: 1 Department of Cancer Surgery, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia 2 Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia 3 Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia 4 Department of Cancer Medicine, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia 5 Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia.
authors: Daniel A
authors: DA
authors: Schneider
authors: Timothy J
authors: TJ
authors: Akhurst
authors: Samuel Y
authors: SY
authors: Ngan
authors: Satish K
authors: SK
authors: Warrier
authors: Michael
authors: M
authors: Michael
authors: Andrew C
authors: AC
authors: Lynch
authors: Luc
authors: L
authors: Te Marvelde
authors: Alexander G
authors: AG
authors: Heriot
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D003082:Colectomy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011300:Preoperative Care / Q000379:methods*; D011379:Prognosis; D012004:Rectal Neoplasms / Q000175:diagnosis* / Q000628:therapy; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*