title: Repeated Postoperative Follow-up Diffusion-weighted Magnetic Resonance Imaging to Detect Residual or Recurrent Cholesteatoma.
abstract: OBJECTIVE
  In our institution, follow-up diffusion-weighted imaging (DWI) after cholesteatoma surgery is performed at least twice. The aim of this study was to determine the yield of the second follow-up DWI (D-W MRI-2) in patients in whom the first postoperative DWI (D-W MRI-1) was negative for residual or recurrent cholesteatoma.
  
  
  METHODS
  A retrospective analysis.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Patients were included if 1) they had at least two postoperative DWI examinations after a canal wall up procedure with apparently complete cholesteatoma resection; 2) D-W MRI-1 was performed between 6 and 24 months after surgery and D-W MRI-2 performed at least 6 months after D-W MRI-1; 3) both DWI examinations were of good quality and covering the whole mastoid-middle ear region; 4) D-W MRI-1 was unequivocally negative for cholesteatoma; and 5) there was no clinical suspicion on otoscopy of recurrent cholesteatoma nor a surgical intervention between these two postoperative DWI examinations. In total, 45 separate ears in 44 patients were included.
  
  
  RESULTS
  In 14 ears (31%) D-W MRI-2 was positive (n = 8) or equivocal (n = 6) for cholesteatoma. In six of eight patients with positive D-W MRI-2, follow-up surgery was performed. Cholesteatoma was found in five of them. None of the patients with equivocal findings on D-W MRI-2 was operated on. Patients with positive D-W MRI-2 were of young age. There were no observable differences for sex, side, time between surgery and D-W MRI-1, time between surgery and D-W MRI-2, or time between D-W MRI-1 and D-W MRI-2, or for the location of cholesteatoma at surgery. In the study period there was a trend to perform D-W MRI-1 and D-W MRI-2 earlier after initial surgery. In the same period, there was an evident decrease in average age of the patient population.
  
  
  CONCLUSIONS
  Despite cholesteatoma surgery without macroscopic residue, clinical follow-up and routine first follow-up DWI without any signs of residual or recurrent disease, repeat follow-up DWI showed evidence of cholesteatoma in 31% of patients. On the basis of the findings in this study, repeated follow-up DWI is recommended.
authors.affiliation: *Department of Radiology and Nuclear Medicine †Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Stefan
authors.initials: S
authors.lastname: Steens
authors.forename: Wulphert
authors.initials: W
authors.lastname: Venderink
authors.forename: Dirk
authors.initials: D
authors.lastname: Kunst
authors.forename: Anton
authors.initials: A
authors.lastname: Meijer
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Mylanus
mesh_terms: D000328:Adult; D018424:Cholesteatoma, Middle Ear / Q000175:diagnosis* / Q000601:surgery; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004432:Ear, Middle / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D012008:Recurrence; D012189:Retrospective Studies