title: Transrectal ultrasound color Doppler in the evaluation of recurrence of anal canal cancer.
abstract: OBJECTIVE
  aim was to obtain elements for a differential diagnosis between post-radiation fibrosis and residual tumor or local relapse in anal canal cancer through detection of presence/absence of intralesional blood flow. Transrectal ultrasound and color Doppler were compared.
  
  
  METHODS
  43 patients underwent transrectal ultrasound sonography and color Doppler before and after therapy to assess intralesional blood flow and flow pattern (spotty and linear signals). All diagnostic imaging results were compared to histological analysis. Specificity was submitted to statistical analysis using McNemar test.
  
  
  RESULTS
  before therapy 34 lesions (79%) showed color signal; no signal in 9 (21%), which were excluded from our analysis. Eighteen of the 34 patients considered, presented complete response to therapy, 14 partial response and two no response. After therapy, signal disappeared in 17 patients (94%); one false-positive (6%) presented spotty signals; 16 of 34 patients presented changed color signal. Color Doppler showed higher specificity than grey scale transrectal ultrasound in the differentiation of fibrosis from tumor. Response was confirmed by histological examination, considered gold standard. McNemar test demonstrated the significance of color Doppler (P < 0.0001).
  
  
  CONCLUSIONS
  color Doppler considerably increases transrectal ultrasound specificity in differentiating tumor relapse from fibrosis in anal canal cancer.
authors.affiliation: Department of Radiology, University La Sapienza, Policlinico Umberto I, V.le Regina Elena 324, 00161 Rome, Italy. francescom.drudi@uniroma1.it
authors.forename: Francesco M
authors.initials: FM
authors.lastname: Drudi
authors.forename: Francesco
authors.initials: F
authors.lastname: Giovagnorio
authors.forename: Nicola
authors.initials: N
authors.lastname: Raffetto
authors.forename: Paolo
authors.initials: P
authors.lastname: Ricci
authors.forename: Fiammetta
authors.initials: F
authors.lastname: Cascone
authors.forename: Mario
authors.initials: M
authors.lastname: Santarelli
authors.forename: Francesca
authors.initials: F
authors.lastname: Trippa
authors.forename: Roberto
authors.initials: R
authors.lastname: Passariello
mesh_terms: D001003:Anal Canal / Q000473:pathology; D001005:Anus Neoplasms / Q000000981:diagnostic imaging*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D005355:Fibrosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D011832:Radiation Injuries / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color; D018084:Ultrasonography, Interventional