title: The assessment of local response using magnetic resonance imaging at 3- and 6-month post chemoradiotherapy in patients with anal cancer.
abstract: OBJECTIVE
  To assess the use of MRI-determined tumour regression grading (TRG) in local response assessment and detection of salvageable early local relapse after chemoradiotherapy (CRT) in patients with anal squamous cell carcinoma (ASCC).
  
  
  METHODS
  From a prospective database of patients with ASCC managed through a centralised multidisciplinary team, 74 patients who completed routine post-CRT 3- and 6-month MRIs (2009-2012) were reviewed. Two radiologists blinded to the outcomes consensus read and retrospectively assigned TRG scores [1 (complete response) to 5 (no response)] and related these to early local relapse (within 12 months) and disease-free survival (DFS).
  
  
  RESULTS
  Seven patients had early local relapse. TRG 1/2 scores at 3 and 6 months had a 100 % negative predictive value; TRG 4/5 scores at 6 months had a 100 % positive predictive value. All seven patients underwent salvage R0 resections. We identified a novel 'tram-track' sign on MRI in over half of patients, with an NPV for early local relapse of 83 % at 6 months. No imaging characteristic or TRG score independently prognosticated for late relapse or 3-year DFS.
  
  
  CONCLUSIONS
  Post-CRT 3- and 6-month MRI-determined TRG scores predicted salvageable R0 early local relapses in patients with ASCC, challenging current clinical guidelines.
  
  
  CONCLUSIONS
  • Post-chemoradiotherapy MRI (3 and 6 months) helps local response assessment in ASCC. • The MRI-TRG system can be used reproducibly in patients with ASCC. • The TRG system facilitates patient selection for examination under anaesthesia and biopsy. • The use of MRI-TRG predicts for detection of salvageable early local relapses. • The TRG system allows for a standardised follow-up pathway.
authors.affiliation: Department of Radiology, The Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK. rohit.kochhar@christie.nhs.uk.|Institute of Cancer Sciences, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK. rohit.kochhar@christie.nhs.uk.
authors.forename: Rohit
authors.initials: R
authors.lastname: Kochhar
authors.affiliation: Institute of Cancer Sciences, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK.|Department of Surgery, The Christie NHS Foundation Trust, Manchester, UK.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Renehan
authors.affiliation: Department of Radiology, The Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK.
authors.forename: Damian
authors.initials: D
authors.lastname: Mullan
authors.affiliation: Department of Histopathology, The Christie NHS Foundation Trust, Manchester, UK.
authors.forename: Bipasha
authors.initials: B
authors.lastname: Chakrabarty
authors.affiliation: Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Saunders
authors.affiliation: Department of Radiology, The Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK.
authors.forename: Bernadette M
authors.initials: BM
authors.lastname: Carrington
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001003:Anal Canal / Q000000981:diagnostic imaging / Q000473:pathology; D001005:Anus Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Anus neoplasms; Carcinoma, squamous cell; Chemoradiotherapy; Magnetic resonance imaging; Tumour response