title: Efficacy of qualitative response assessment interpretation criteria at 18F-FDG PET-CT for predicting outcome in locally advanced cervical carcinoma treated with chemoradiotherapy.
abstract: OBJECTIVE
  To evaluate the utility of a standardized qualitative scoring system for treatment response assessment at 18F-FDG PET-CT in patients undergoing chemoradiotherapy for locally advanced cervical carcinoma and correlate this with subsequent patient outcome.
  
  
  METHODS
  Ninety-six consecutive patients with locally advanced cervical carcinoma treated with radical chemoradiotherapy (CRT) in a single centre between 2011 and 2014 underwent 18F-FDG PET-CT approximately 3 months post-treatment. Tumour metabolic response was assessed qualitatively using a 5-point scale ranging from background level activity only through to progressive metabolic disease. Clinical and radiological (MRI pelvis) follow-up was performed in all patients. Progression-free (PFS) and overall survival (OS) was calculated using the Kaplan-Meier method (Mantel-Cox log-rank) and correlated with qualitative score using Chi-squared test.
  
  
  RESULTS
  Forty patients (41.7 %) demonstrated complete metabolic response (CMR) on post-treatment PET-CT (Score 1/2) with 38 patients (95.0 %) remaining disease free after a minimum follow-up period of 18 months. Twenty-four patients (25.0 %) had indeterminate residual uptake (ID, Score 3) at primary or nodal sites after treatment, of these eight patients (33.3 %) relapsed on follow-up, including all patients with residual nodal uptake (n = 4Eleven11 of 17 patients (64.7 %) with significant residual uptake (partial metabolic response, PMR, Score 4) subsequently relapsed. In 15 patients (15.6 %) PET-CT demonstrated progressive disease (PD, Score 5) following treatment. Kaplan-Meier analysis showed a highly statistically significant difference in PFS and OS between patients with CMR, indeterminate uptake, PMR and PD (Log-rank, P < 0.0001). Chi-squared test demonstrated a highly statistically significant association between increasing qualitative score and risk of recurrence or death (P < 0.001).
  
  
  CONCLUSIONS
  Use of a 5-point qualitative scoring system to assess metabolic response to CRT in locally advanced cervical carcinoma predicts survival outcome and this prognostic information may help guide further patient management.
authors.affiliation: Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK. a.scarsbrook@nhs.net.|Department of Nuclear Medicine, Leeds Teaching Hospitals NHS Trust, Level 1, Bexley Wing, St James's University Hospital, Becket Street, Leeds, LS9 7TF, UK. a.scarsbrook@nhs.net.|Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK. a.scarsbrook@nhs.net.
authors.forename: Andrew
authors.identifier: http://orcid.org/0000-0002-4243-032X
authors.initials: A
authors.lastname: Scarsbrook
authors.affiliation: Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK.|Department of Nuclear Medicine, Leeds Teaching Hospitals NHS Trust, Level 1, Bexley Wing, St James's University Hospital, Becket Street, Leeds, LS9 7TF, UK.
authors.forename: Sriram
authors.initials: S
authors.lastname: Vaidyanathan
authors.affiliation: Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK.|Department of Nuclear Medicine, Leeds Teaching Hospitals NHS Trust, Level 1, Bexley Wing, St James's University Hospital, Becket Street, Leeds, LS9 7TF, UK.
authors.forename: Fahmid
authors.initials: F
authors.lastname: Chowdhury
authors.affiliation: Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Swift
authors.affiliation: Department of Clinical Oncology, Leeds Teaching Hospitals NHS Trust, Leeds, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Cooper
authors.affiliation: Department of Radiology, Leeds Teaching Hospitals NHS Trust, Leeds, UK.|Department of Nuclear Medicine, Leeds Teaching Hospitals NHS Trust, Level 1, Bexley Wing, St James's University Hospital, Becket Street, Leeds, LS9 7TF, UK.
authors.forename: Chirag
authors.initials: C
authors.lastname: Patel
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000628:therapy; D059248:Chemoradiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: FDG PET-CT; cervical cancer; qualitative scoring; radiotherapy; survival analysis; therapy assessment