title: Clinical trials of a urethral dose measurement system in brachytherapy using scintillation detectors.
abstract: OBJECTIVE
  To report on the clinical feasibility of a novel scintillation detector system with fiberoptic readout that measures the urethral dose during high-dose-rate brachytherapy treatment of the prostate.
  
  
  METHODS
  The clinical trial enrolled 24 patients receiving high-dose-rate brachytherapy treatment to the prostate. After the first 14 patients, three improvements were made to the dosimeter system design to improve clinical reliability: a dosimeter self-checking facility; a radiopaque marker to determine the position of the dosimeter, and a more robust optical extension fiber.
  
  
  RESULTS
  Improvements to the system design allowed for accurate dose measurements to be made in vivo. A maximum measured dose departure of 9% from the calculated dose was observed after dosimeter design improvements.
  
  
  CONCLUSIONS
  Departures of the measured from the calculated dose, after improvements to the dosimetry system, arise primarily from small changes in patient anatomy. Therefore, we recommend that patient response be correlated with the measured in vivo dose rather than with the calculated dose.
authors.affiliation: Radiation Oncology, Royal Prince Alfred Hospital, New South Wales, Australia. natalka@email.cs.nsw.gov.au
authors.forename: Natalka
authors.initials: N
authors.lastname: Suchowerska
authors.forename: Michael
authors.initials: M
authors.lastname: Jackson
authors.forename: Jamil
authors.initials: J
authors.lastname: Lambert
authors.forename: Yong Bai
authors.initials: YB
authors.lastname: Yin
authors.forename: George
authors.initials: G
authors.lastname: Hruby
authors.forename: David R
authors.initials: DR
authors.lastname: McKenzie
mesh_terms: D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D005336:Fiber Optic Technology / Q000379:methods; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012588:Scintillation Counting / Q000295:instrumentation*; D047368:Tumor Burden; D014521:Urethra / Q000528:radiation effects*