title: CT or MRI for image-based brachytherapy in cervical cancer.
abstract: OBJECTIVE
  To compare volumes and doses of tumour and organs at risk with computed tomography vs. magnetic resonance imaging in cervical cancer brachytherapy.
  
  
  METHODS
  Seventeen previously untreated patients with cervical cancer suitable for radical treatment were included. All patients underwent brachytherapy using a magnetic resonance imaging-compatible applicator followed by both computed tomography and magnetic resonance imaging. The tumour and organs at risk (bladder, rectum, sigmoid and intestines) were contoured on computed tomography using only clinical findings and on magnetic resonance imaging using GEC-ESTRO guidelines. The volume and doses for tumour and organs at risk were evaluated using two-sided t-test.
  
  
  RESULTS
  When magnetic resonance imaging information is not included in contouring on computed tomography images, there is significant underestimation of tumour height and overestimation of the width (P< 0.05). However, there was no significant difference in V(100), D(90) and D(100) for high- and intermediate-risk clinical target volume in computed tomography and magnetic resonance imaging. The volumes and doses to 0.1, 1 and 2 cc for organs at risk were also similar.
  
  
  CONCLUSIONS
  Magnetic resonance imaging remains the gold standard for tumour delineation, but computed tomography with clinical information can give comparable results, which need to be studied further. Computed tomography-based contouring can be used comfortably for delineation of organs at risk.
authors.affiliation: Radiation Oncology, Tata Memorial Hospital, Parel, Mumbai 400012, India. krishnatry@gmail.com
authors.forename: Rahul
authors.initials: R
authors.lastname: Krishnatry
authors.forename: Firuza D
authors.initials: FD
authors.lastname: Patel
authors.forename: Paramjeet
authors.initials: P
authors.lastname: Singh
authors.forename: Suresh C
authors.initials: SC
authors.lastname: Sharma
authors.forename: Arun S
authors.initials: AS
authors.lastname: Oinam
authors.forename: Arvind K
authors.initials: AK
authors.lastname: Shukla
mesh_terms: D000328:Adult; D001918:Brachytherapy / Q000379:methods; D005260:Female; D006801:Humans; D007422:Intestines / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000473:pathology; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging