title: Dosimetric comparison of MRI-based HDR brachytherapy and stereotactic radiotherapy in patients with advanced cervical cancer: A virtual brachytherapy study.
abstract: OBJECTIVE
  To evaluate the treatment plans of 3D image-guided brachytherapy (BT) and stereotactic robotic radiotherapy with online image guidance - CyberKnife (CK) in patients with locally advanced cervix cancer.
  
  
  METHODS
  Ten pairs of plans for patients with locally advanced inoperable cervical cancer were created using MR based 3D brachytherapy and stereotaxis CK. The dose that covers 98% of the target volume (HR CTV D98) was taken as a reference and other parameters were compared.
  
  
  RESULTS
  Of the ten studied cases, the dose from D100 GTV was comparable for both devices, on average, the BT GTV D90 was 10-20% higher than for CK. The HR CTV D90 was higher for CK with an average difference of 10-20%, but only fifteen percent of HR CTV (the peripheral part) received a higher dose from CK, while 85% of the target volume received higher doses from BT. We found a significant organ-sparing effect of CK compared to brachytherapy (20-30% lower doses in 0.1 cm(3), 1 cm(3), and 2 cm(3)).
  
  
  CONCLUSIONS
  BT remains to be the best method for dose escalation. Due to the significant organ-sparing effect of CK, patients that are not candidates for BT could benefit from stereotaxis more than from classical external beam radiotherapy.
authors.affiliation: Department of Oncology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: Bretislav
authors.initials: B
authors.lastname: Otahal
authors.affiliation: Oncology Centre, Multiscan & Pardubice Regional Hospital, Pardubice, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Dolezel
authors.affiliation: Department of Oncology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: Jakub
authors.initials: J
authors.lastname: Cvek
authors.affiliation: Department of Gynecology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Simetka
authors.affiliation: Department of Gynecology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Klat
authors.affiliation: Department of Oncology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: Lukas
authors.initials: L
authors.lastname: Knybel
authors.affiliation: Department of Oncology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: Lukas
authors.initials: L
authors.lastname: Molenda
authors.affiliation: Department of Oncology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Skacelikova
authors.affiliation: Oncology Centre, Multiscan & Pardubice Regional Hospital, Pardubice, Czech Republic.
authors.forename: Ales
authors.initials: A
authors.lastname: Hlavka
authors.affiliation: Department of Oncology, University Hospital Ostrava, Ostrava, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Feltl
keywords: Brachytherapy; Cervix carcinoma; CyberKnife; Dosimetric study; Stereotactic radiotherapy