title: Early prediction of anticancer effects with diffusion-weighted MR imaging in patients with colorectal liver metastases following selective internal radiotherapy.
abstract: OBJECTIVE
  To prospectively evaluate diffusion-weighted imaging (DWI) for early prediction of tumour response in patients with colorectal liver metastases following selective internal radiotherapy (SIRT).
  
  
  METHODS
  We evaluated 41 metastases in 21 patients, age 62.9 ± 9.9 years. All patients underwent magnetic resonance imaging (MRI) including breath-hold echoplanar DWI sequences. Imaging was performed before therapy (baseline MRI), 2 days after SIRT (early MRI) as well as 6 weeks later (follow-up MRI). Tumour volume (TV) and intratumoural apparent diffusion coefficient (ADC) were measured independently by two radiologists at all time points.
  
  
  RESULTS
  Metastases were categorised as responding lesions (RL; n = 33) or non-responding lesions (NRL; n = 8) according to changes in TV after 6 weeks. We found an inverse correlation of changes in TV and ADC at follow-up MRI with a Pearson's correlation coefficient of r = -0.66 (p < 0.0001). On early MRI, no significant changes in TV were found for either RL or NRL. Conversely, ADC decreased significantly in RL by 10.7 ± 8.4% (p < 0.0001). ADC increased in NRL by 9.6 ± 20.8%, which was not statistically significant (p = 0.40).
  
  
  CONCLUSIONS
  DWI was capable of predicting therapy effects of SIRT in patients with colorectal hepatic metastases as early as 2 days following treatment.
authors.affiliation: Department of Radiology and Nuclear Medicine, University of Magdeburg, Magdeburg, Germany. oliver.dudeck@med.ovgu.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Dudeck
authors.forename: Martin
authors.initials: M
authors.lastname: Zeile
authors.forename: Christian
authors.initials: C
authors.lastname: Wybranski
authors.forename: Alice
authors.initials: A
authors.lastname: Schulmeister
authors.forename: Frank
authors.initials: F
authors.lastname: Fischbach
authors.forename: Maciej
authors.initials: M
authors.lastname: Pech
authors.forename: Gero
authors.initials: G
authors.lastname: Wieners
authors.forename: Ricarda
authors.initials: R
authors.lastname: Rühl
authors.forename: Oliver
authors.initials: O
authors.lastname: Grosser
authors.forename: Holger
authors.initials: H
authors.lastname: Amthauer
authors.forename: Jens
authors.initials: J
authors.lastname: Ricke
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy; D015179:Colorectal Neoplasms / Q000473:pathology*; D003131:Combined Modality Therapy; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
chemical_list: D015021:Yttrium Radioisotopes