title: Intensity-modulated radiation therapy versus conventional radiation therapy for squamous cell carcinoma of the anal canal.
abstract: BACKGROUND
  The purpose of this study was to compare outcomes in patients with anal canal squamous cell carcinoma (SCCA) who were treated with definitive chemoradiotherapy by either intensity-modulated radiation therapy (IMRT) or conventional radiotherapy (CRT).
  
  
  METHODS
  Forty-six patients who received definitive chemoradiotherapy from January 1993 to August 2009 were included. Forty-five patients received 5-fluorouracil with mitomycin C (n = 39) or cisplatin (n = 6). Seventeen (37%) were treated with CRT and 29 (63%) with IMRT. The median dose was 54 Gy in both groups. Median follow-up was 26 months (CRT) and 32 months (IMRT). T3-T4 stage (P = .18) and lymph node-positive disease (P = .6) were similar between groups.
  
  
  RESULTS
  The CRT group required longer treatment duration (57 days vs 40 days, P < .0001), more treatment breaks (88% vs 34.5%, P = .001), and longer breaks (12 days vs 1.5 days, P < .0001) than patients treated with IMRT. Eleven (65%) patients in the CRT group experienced grade >2 nonhematologic toxicity compared with 6 (21%) patients in the IMRT group (P = .003). The 3-year overall survival (OS), locoregional control (LRC), and progression-free survival were 87.8%, 91.9%, and 84.2%, respectively, for the IMRT groups and 51.8%, 56.7%, and 56.7%, respectively, for the CRT group (all P < .01). On multivariate analysis, T stage, use of IMRT, and treatment duration were associated with OS, and T stage and use of IMRT were associated with LRC.
  
  
  CONCLUSIONS
  The use of IMRT was associated with less toxicity, reduced need for treatment breaks, and excellent LRC and OS compared with CRT in patients with SCCA of the anal canal.
authors.affiliation: Department of Radiation Oncology, Stanford University, Stanford, CA, USA.
authors.forename: Jose G
authors.initials: JG
authors.lastname: Bazan
authors.forename: Wendy
authors.initials: W
authors.lastname: Hara
authors.forename: Annie
authors.initials: A
authors.lastname: Hsu
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Kunz
authors.forename: James
authors.initials: J
authors.lastname: Ford
authors.forename: George A
authors.initials: GA
authors.lastname: Fisher
authors.forename: Mark L
authors.initials: ML
authors.lastname: Welton
authors.forename: Andrew
authors.initials: A
authors.lastname: Shelton
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Kapp
authors.forename: Albert C
authors.initials: AC
authors.lastname: Koong
authors.forename: Karyn A
authors.initials: KA
authors.lastname: Goodman
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Chang
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001005:Anus Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000532:radiotherapy*; D002945:Cisplatin / Q000008:administration & dosage; D003131:Combined Modality Therapy; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D016685:Mitomycin / Q000008:administration & dosage; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D016019:Survival Analysis
chemical_list: D016685:Mitomycin; D002945:Cisplatin; D005472:Fluorouracil