title: A detailed dosimetric comparison between manual and inverse plans in HDR intracavitary/interstitial cervical cancer brachytherapy.
abstract: OBJECTIVE
  The purpose of this study was to compare two inverse planning algorithms for cervical cancer brachytherapy and a conventional manual treatment planning according to the MUW (Medical University of Vienna) protocol.
  
  
  METHODS
  For 20 patients, manually optimized, and, inversely optimized treatment plans with Hybrid Inverse treatment Planning and Optimization (HIPO) and with Inverse Planning Simulated Annealing (IPSA) were created. Dosimetric parameters, absolute volumes of normal tissue receiving reference doses, absolute loading times of tandem, ring and interstitial needles, Paddick and COIN conformity indices were evaluated.
  
  
  RESULTS
  HIPO was able to achieve a similar dose distribution to manual planning with the restriction of high dose regions. It reduced the loading time of needles and the overall treatment time. The values of both conformity indices were the lowest. IPSA was able to achieve acceptable dosimetric results. However, it overloaded the needles. This resulted in high dose regions located in the normal tissue. The Paddick index for the volume of two times prescribed dose was outstandingly low.
  
  
  CONCLUSIONS
  HIPO can produce clinically acceptable treatment plans with the elimination of high dose regions in normal tissue. Compared to IPSA, it is an inverse optimization method which takes into account current clinical experience gained from manual treatment planning.
authors.affiliation: Department of Radiotherapy, Medical University of Vienna, Austria.
authors.forename: Petra
authors.initials: P
authors.lastname: Trnková
authors.affiliation: Department of Medical Physics & Engineering, Strahlenklinik, Klinikum Offenbach GmbH, Germany; Nuclear and Particle Physics Section, Physics Department, University of Athens, Athens, Greece.
authors.forename: Dimos
authors.initials: D
authors.lastname: Baltas
authors.affiliation: Pi-Medical Ltd., Athens, Greece.
authors.forename: Andreas
authors.initials: A
authors.lastname: Karabis
authors.affiliation: Department of Radiotherapy, Medical University of Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Stock
authors.affiliation: Department of Radiotherapy, Medical University of Vienna, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Dimopoulos
authors.affiliation: Department of Radiotherapy, Medical University of Vienna, Austria.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Georg
authors.affiliation: Department of Radiotherapy, Medical University of Vienna, Austria.
authors.forename: Richard
authors.initials: R
authors.lastname: Pötter
authors.affiliation: Department of Radiotherapy, Medical University of Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Kirisits
keywords: HIPO; IPSA; brachytherapy; cervix; inverse planning