title: Three-dimensional anal endosonography may improve detection of recurrent anal cancer.
abstract: OBJECTIVE
  In our center since 2001, follow-up examination has included three-dimensional endosonography in all patients with suspicion of local recurrence of anal cancer. This study was designed to investigate whether three-dimensional endosonography surpassed two-dimensional endosonography as a diagnostic tool for patients with suspected local recurrence.
  
  
  METHODS
  This prospective study included 38 consecutive patients who have had anal carcinoma and were investigated using three-dimensional endosonography in combination with anoscopy and digital rectal examination at Rigshospitalet from July 2001 to January 2005 under suspicion of local recurrence. All endosonographic examinations-two-dimensional, three-dimensional, and three-dimensional in combination with anoscopy and digital rectal examination-were evaluated by blinded observers. The observers scored each examination according to a five-point scale in which a score from 1 to 3 was regarded as benign endosonographic findings and a score from 4 to 5 was regarded as malignant endosonographic findings. The endosonographic diagnosis for each examination was compared with histologic evaluation or when no biopsy had been taken with a follow-up period of at least six months. If a patient showed no signs of local recurrence in the follow-up period, no local recurrence was considered to be present at the time of the investigation.
  
  
  RESULTS
  The sensitivity was 1.0 for three-dimensional endosonography in combination with palpation, 0.86 for three-dimensional endosonography alone, and 0.57 for two-dimensional endosonography. The differences between two-dimensional endosonography and three-dimensional endosonography alone as well as two-dimensional endosonography and three-dimensional endosonography + anoscopy and digital rectal examination both reached significance with P values <0.05.
  
  
  CONCLUSIONS
  This study indicates that three-dimensional endosonography surpasses two-dimensional endosonography in the evaluation of patients with suspicion of local recurrence of anal cancer especially in combination with anoscopy and digital rectal examination.
authors.affiliation: Department of Radiology, Section of Ultrasound X4123, Copenhagen University Hospital, Blegdamsvej 9, DK 2100 Copenhagen, Denmark.
authors.forename: Anders F
authors.initials: AF
authors.lastname: Christensen
authors.forename: Michael B
authors.initials: MB
authors.lastname: Nielsen
authors.forename: Lars B
authors.initials: LB
authors.lastname: Svendsen
authors.forename: Svend A
authors.initials: SA
authors.lastname: Engelholm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000000981:diagnostic imaging*; D001005:Anus Neoplasms / Q000000981:diagnostic imaging*; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012680:Sensitivity and Specificity