title: Three-dimensional real-time magnetic resonance-guided interstitial prostate brachytherapy optimizes radiation dose distribution resulting in a favorable acute side effect profile in patients with clinically localized prostate cancer.
abstract: OBJECTIVE
  A large number of men are diagnosed with early-stage prostate cancer as a result of prostate-specific antigen (PSA) screening. For many of these men, prostatectomy results in long-term freedom from biochemical and clinical failure. Despite limited follow-up data, ultrasound-guided prostate brachytherapy has gained acceptance as a treatment for early-stage prostate cancer, in part due to its favorable side effect profile and brief recovery period. We report on the use of three-dimensional real-time magnetic resonance (MR) guidance, which has several advantages compared with biplanar ultrasound guidance for prostate brachytherapy, including enhanced geometric and dosimetric feedback during the procedure.
  
  
  METHODS
  Median clinical target volume coverage of 96% was achieved using MR guidance. The ability to define more precisely the clinical target volume with MR and the use of real-time assessment of dose distribution resulted in an excellent acute side effect profile. Only 19% of patients required oral alpha1 blockers for postimplant urethritis and 9% required temporary reinsertion of the Foley catheter due to acute urinary obstruction.
  
  
  CONCLUSIONS
  These results compare favorably to those of ultrasound-guided brachytherapy. Further follow-up is needed to ascertain the impact this technique will have on cancer control and long-term quality of life.
authors.affiliation: Joint Center for Radiation Therapy, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Hurwitz
authors.forename: R
authors.initials: R
authors.lastname: Cormack
authors.forename: C M
authors.initials: CM
authors.lastname: Tempany
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: A V
authors.initials: AV
authors.lastname: D'Amico
mesh_terms: D000368:Aged; D001918:Brachytherapy; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000532:radiotherapy*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D012189:Retrospective Studies; D016896:Treatment Outcome; D001743:Urinary Bladder / Q000528:radiation effects; D014555:Urination Disorders / Q000517:prevention & control*
chemical_list: D007457:Iodine Radioisotopes