title: Predictive criteria for MRI-based evaluation of response both during and after radiotherapy for cervical cancer.
abstract: OBJECTIVE
  For cervical carcinoma, the presence of persistent disease after radiotherapy (RT) is a significant predictor for survival. To date, no standard protocol is available to evaluate a response. This study was performed to assess magnetic resonance imaging (MRI) to evaluate presence of local residual disease during and after RT for Federation of Gynecology and Obstetrics (FIGO) stage Ib1-IVa cervical cancer.
  
  
  METHODS
  Forty-two patients were included. Patients underwent MRI before external beam RT, at final intracavitary brachytherapy (BCT) and 2-3 months after completion of RT. Two blinded radiologists (observer 1: experienced, observer 2: less experienced) scored the likelihood of residual tumor. Magnetic resonance imaging was evaluated by means of (a) 'subjective' visual evaluation of T2 weighted MRI images, and (b) 'objective' visual evaluation of T2 weighted MRI images according to predefined imaging criteria.
  
  
  RESULTS
  Seven patients had residual disease. Area under the receiver operating characteristics curve (AUC) for 'subjective' visual assessment was 0.79/0.75 (observer 1/observer 2) after RT and 0.75/0.43 at final BCT. The combined 'objective' MRI criteria (isointense, nodular, and irregular) resulted in improved prediction of residual tumor (AUCs of 0.91/0.85 after RT). For the less experienced observer, the MRI criteria set significantly improved prediction of residual tumor compared to 'subjective' visual assessment. Observer dependency decreased, kappa of 0.41 compared to 0.84 for the MRI criteria set after RT.
  
  
  CONCLUSIONS
  Compared to 'subjective' visual assessment, predefined 'objective' MRI criteria increase diagnostic performance and decrease observer dependency for assessing residual tumor after RT in cervical cancer.
authors: Department of Obstetrics & Gynecology, Maastricht University Medical Centre, Maastricht.
authors: Jordy
authors: J
authors: Mongula
authors: Department of Obstetrics & Gynecology, Maastricht University Medical Centre, Maastricht; GROW, School for Oncology and Developmental Biology, Maastricht.
authors: Brigitte
authors: B
authors: Slangen
authors: Department of Radiology, Maastricht University Medical Centre.
authors: Doenja
authors: D
authors: Lambregts
authors: Department of Radiology, Maastricht University Medical Centre.
authors: Frans
authors: F
authors: Bakers
authors: Department of Radiology, Maastricht University Medical Centre.
authors: Shekar
authors: S
authors: Mahesh
authors: GROW, School for Oncology and Developmental Biology, Maastricht; MAASTRO Clinic, Maastricht.
authors: Ludy
authors: L
authors: Lutgens
authors: Department of Obstetrics & Gynecology, Maastricht University Medical Centre, Maastricht; GROW, School for Oncology and Developmental Biology, Maastricht.
authors: Toon
authors: T
authors: Van Gorp
authors: Department of Radiology, Heerlen Atrium Medical Centre, Heerlen, The Netherlands.
authors: Roy
authors: R
authors: Vliegen
authors: Department of Obstetrics & Gynecology, Maastricht University Medical Centre, Maastricht; GROW, School for Oncology and Developmental Biology, Maastricht.
authors: Roy
authors: R
authors: Kruitwagen
authors: GROW, School for Oncology and Developmental Biology, Maastricht; Department of Radiology, Maastricht University Medical Centre.
authors: Regina
authors: R
authors: Beets-Tan
keywords: brachytherapy; cervical cancer; cervical carcinoma; magnetic resonance imaging; radiation therapy