title: [Physical basics and clinical realization of interstitial brachytherapy of the prostate with iodine 125].
abstract: BACKGROUND
  Interstitial brachytherapy with I-125 seeds can be used for successful treatment of early stage prostate cancer. There is presented the technique of permanent transperineal implantation of I-125 seeds with intraoperative treatment planning which is suited for the treatment of prostate cancer up to the clinical stage of T2a.
  
  
  METHODS
  Some weeks before the implantation of the seeds the prostate volume is determined using transrectal ultrasound (TRUS) so as to estimate the required number of I-125 seeds. At the outset of the treatment the prostate is stabilized by two perineally inserted needles. Subsequently there is carried out an ultrasound guided treatment planning that allows to optimize the distribution of the seeds within the prostate. In interstitial brachytherapy we use RAPID STRANDS((R)), i. e. the I-125 seeds are embedded in vicryl suture at distances of 1 cm. During implantation of the I-125 seeds the transversal placement of the applicator needles is controlled by TRUS and the cranio-caudal placement of the applicator needles is controlled using the fluoroscopic unit as well as TRUS. About 4 weeks after the implantation of the seeds there is carried out a postoperative computation of the dose distribution of the implant using CT imaging.
  
  
  RESULTS
  The procedure possesses the advantage that ultrasound imaging, treatment planning and seed implantation are carried out with the prostate remaining in an unaltered position. During implantation the combined imaging of TRUS and fluoroscopy allows a safe placement of the seeds with in the prostate.
  
  
  CONCLUSIONS
  The methods for the calculation of the actually attained dose distribution must still be optimized, because the postoperative examination of the individual results has so far been possible only with difficulties resulting from methodological inconveniences.
authors.affiliation: Abteilung Medizinische Physik, Universitätsklinik für Radioonkologie, Tübingen, Germany. theodor.kaulich@med.uni-tuebingen.de
authors.forename: Theodor W
authors.initials: TW
authors.lastname: Kaulich
authors.forename: Ulf
authors.initials: U
authors.lastname: Lamprecht
authors.forename: Frank
authors.initials: F
authors.lastname: Paulsen
authors.forename: Frank
authors.initials: F
authors.lastname: Kahmann
authors.forename: Uwe
authors.initials: U
authors.lastname: Maurer
authors.forename: Thomas Oliver
authors.initials: TO
authors.lastname: Henkel
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Loeser
authors.forename: Karl-Horst
authors.initials: KH
authors.lastname: Bichler
authors.forename: Fridtjof
authors.initials: F
authors.lastname: Nüsslin
authors.forename: Michael
authors.initials: M
authors.lastname: Bamberg
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D003198:Computer Simulation; D019160:Endosonography / Q000295:instrumentation; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation; D014057:Tomography, X-Ray Computed
chemical_list: D007457:Iodine Radioisotopes