title: Template guided transperineal saturation biopsy of the prostate: lessons for focal and urethra-sparing high-dose-rate brachytherapy for localized prostate cancer.
abstract: OBJECTIVE
  The aim of this work is to evaluate results of prostate transperineal saturation biopsy as a guide for focal high-dose-rate brachytherapy in patients with prostate cancer (PCa).
  
  
  METHODS
  Template guided saturation biopsy was performed in 67 primary patients with suspicion for prostate cancer. Biopsy was performed under ultrasonography (US) control with the help of brachytherapy grid and 5 mm distance between samples. We put special attention for accurate sampling of prostate in periurethral region. The number of cores varied from 17 to 81 (average 36 cores). Finally, in 40 patients with confirmed prostate cancer results of biopsy were used for brachytherapy planning.
  
  
  RESULTS
  Saturation biopsy revealed prostate cancer in 40 of 67 evaluated patients. The extent of biopsy core involvement varied from 5% to 100% (average: 57%). Focal nature of PCa (single unilateral tumor nodule) was diagnosed in 10 (25%), multifocal - in another 30 (75%) patients. Hemigland invasion was mentioned in 12 (30%) cases. Saturation biopsy detected PCa in periurethral cores in 27 (67.5%) of 40 evaluated patients. In 10 patients, the extent of involvement in periurethral cores varied between 10% and 50%; in another, 17 observations exceeded 50%. According to results obtained on saturation biopsy, we performed HDR brachytherapy with "urethra low dose tunnel" (D10ur ≤ 80-90%) in 13 patients with noninvolved periurethral cores. Theoretically, hemigland brachytherapy was possible in 12 of 40 evaluated patients with PCa.
  
  
  CONCLUSIONS
  In low risk patients with PCa results of template guided saturation biopsy indicates high frequency (75%) of multifocal disease and high probability (67.5%) of periurethral invasion. Suitable candidates for focal HDR brachytherapy or irradiation with additional sparing of urethra can be effectively determined with the help of saturation biopsy.
authors.affiliation: Department of Radiation Oncology and Radiology.
authors.forename: Sergey Nikolaevich
authors.initials: SN
authors.lastname: Novikov
authors.affiliation: Department of Radiation Oncology and Radiology.
authors.forename: Sergey Vasilevich
authors.initials: SV
authors.lastname: Kanaev
authors.affiliation: Department of Radiation Oncology and Radiology.
authors.forename: Roman Vladimirovich
authors.initials: RV
authors.lastname: Novikov
authors.affiliation: Department of Radiation Oncology and Radiology.
authors.forename: Nikolay Dmitrievich
authors.initials: ND
authors.lastname: IIlin
authors.affiliation: Pathomorphology Department, N.N. Petrov Institute of Oncology, St. Petersburg, Russia.
authors.forename: Anna Sergeevna
authors.initials: AS
authors.lastname: Artemieva
authors.affiliation: Pathomorphology Department, N.N. Petrov Institute of Oncology, St. Petersburg, Russia.
authors.forename: Alexnder Olegovich
authors.initials: AO
authors.lastname: Ivantcov
authors.affiliation: Department of Radiation Oncology and Radiology.
authors.forename: Evgeniy Alexandrovich
authors.initials: EA
authors.lastname: Piskunov
authors.affiliation: Department of Radiation Oncology and Radiology.
authors.forename: Mariya Yurievna
authors.initials: MY
authors.lastname: Gotovchikova
keywords: HDR; brachytherapy; prostate cancer; saturation biopsy