title: Positron emission tomography/computed tomography in the staging and treatment of anal cancer.
abstract: OBJECTIVE
  This study was intended to determine the role of PET/CT in the staging of anal cancer as a supplement to three-dimensional transanal ultrasound (TAUS) and inguinal ultrasound (US). The impact of the PET/CT on the initial stage and treatment plan proposed by TAUS/US was assessed.
  
  
  METHODS
  Ninety-five (95) patients referred to our clinic between July 1, 2005, and December 31, 2009, were retrospectively reviewed. All patients had biopsy-proven primary squamous cell cancer of the anal canal. There were 65 females (68%) and 30 males (32%), and the median age was 58 years (range, 35-88 years). Six (6%) of the patients were HIV positive. All patients were staged with TAUS/US and PET/CT.
  
  
  RESULTS
  Twenty-eight (28) patients were diagnosed with suspicious perirectal node metastases. TAUS visualized 24 of these, whereas PET/CT detected 15. Suspicious inguinal nodes were visualized on either US or PET/CT in 41 patients. Seventeen (17) of these had confirmed malignant disease on biopsy, and 15 had confirmed benign disease. All 17 patients (100%) with malignant inguinal nodes were diagnosed by PET/CT, whereas US identified 16 (94%). Ten patients were diagnosed with suspicious inguinal nodes on PET/CT that had not been seen on US. One of these was malignant, three were benign, and six were not biopsied. PET/CT diagnosed eight metastatic sites, whereas TAUS/US diagnosed three. PET/CT discovered three of the five synchronous cancers seen in this study. PET/CT upstaged the disease in 14% of the cases and changed the treatment plan proposed by TAUS/US in 17%.
  
  
  CONCLUSIONS
  PET/CT has great potential influence on the staging and treatment of anal cancer. TAUS is important in the staging of the primary tumor and N1-stage, whereas PET/CT seems necessary for the N2/3-stage, the M-stage and synchronous cancers.
authors: Department of Radiation Oncology, Rigshospitalet, Copenhagen, Denmark. joensveistrup@hotmail.com
authors: Joen
authors: J
authors: Sveistrup
authors: Annika
authors: A
authors: Loft
authors: Anne Kiil
authors: AK
authors: Berthelsen
authors: Birthe Merete
authors: BM
authors: Henriksen
authors: Michael Bachmann
authors: MB
authors: Nielsen
authors: Svend Aage
authors: SA
authors: Engelholm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001005:Anus Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary / Q000628:therapy; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007264:Inguinal Canal / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000379:methods