title: Intraoperative optimized inverse planning for prostate brachytherapy: early experience.
abstract: OBJECTIVE
  To demonstrate the feasibility of an intraoperative inverse planning technique with advanced optimization for prostate seed implantation.
  
  
  METHODS
  We have implemented a method for optimized inverse planning of prostate seed implantation in the operating room (OR), based on the genetic algorithm (GA) driven Prostate Implant Planning Engine for Radiotherapy (PIPER). An integrated treatment planning system was deployed, which includes real-time ultrasound image acquisition, treatment volume segmentation, GA optimization, real-time decision making and sensitivity analysis, isodose and DVH evaluation, and virtual reality navigation and surgical guidance. Ten consecutive patients previously scheduled for implantation were included in the series.
  
  
  RESULTS
  The feasibility of the technique was established by careful monitoring of each step in the OR and comparison with conventional preplanned implants. The median elapsed time for complete image capture, segmentation, GA optimization, and plan evaluation was 4, 10, 2.2, and 2 min, respectively. The dosimetric quality of the OR-based plan was shown to be equivalent to the corresponding preplan.
  
  
  CONCLUSIONS
  An intraoperative optimized inverse planning technique was developed for prostate brachytherapy. The feasibility of the method was demonstrated through an early clinical experience.
authors.affiliation: Department of Urology, University of Rochester Medical Center, NY 14642, USA. EdwardMessing@urmc.rochester.edu
authors.forename: E M
authors.initials: EM
authors.lastname: Messing
authors.forename: J B
authors.initials: JB
authors.lastname: Zhang
authors.forename: D J
authors.initials: DJ
authors.lastname: Rubens
authors.forename: R A
authors.initials: RA
authors.lastname: Brasacchio
authors.forename: J G
authors.initials: JG
authors.lastname: Strang
authors.forename: A
authors.initials: A
authors.lastname: Soni
authors.forename: M C
authors.initials: MC
authors.lastname: Schell
authors.forename: P G
authors.initials: PG
authors.lastname: Okunieff
authors.forename: Y
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000465:Algorithms; D001918:Brachytherapy / Q000379:methods*; D003662:Decision Theory; D005240:Feasibility Studies; D006801:Humans; D007432:Intraoperative Period; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D010165:Palladium / Q000627:therapeutic use; D011467:Prostate / Q000473:pathology; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D014463:Ultrasonography
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D010165:Palladium