PURPOSE: To determine whether segmental urethral dosimetry is predictive for the degree of urinary morbidity after prostate brachytherapy in patients with no urinary symptoms before prostate brachytherapy. METHODS AND MATERIALS: Between May 2000 and November 2005, 1,107 patients underwent iodine-125 monotherapy with urethral sparing techniques. A total of 166 patients fulfilled the selection criteria: baseline (International Prostate Symptom Score) IPSS < or =5, no androgen deprivation therapy, and prostate ultrasound planning volumes (PUTV) <45 mL. The median follow-up was 44 months. Urinary morbidity was defined by maximum increase in IPSS, time to IPSS resolution, maximum Radiation Therapy Oncology Group (RTOG) score, time to RTOG resolution, and urinary retention. Surrogate deviated urethra was contoured and doses calculated at the base, mid-prostate, apex, and urogenital diaphragm. Univariate and multivariate analysis was used to evaluate urethral and prostate dosimetry, age, PUTV, and number of needles for their association with urinary morbidity. RESULTS: Urethral dose was fairly constant in all urethra segments except prostate base, where the variation in does was large. On multivariate analysis, higher urethral base D50, V100, and larger PUTV were predictive for higher maximum increase in IPSS. Higher urethral base V100 and larger PUTV predicted for prolonged IPSS resolution. Higher urethral base D50 and larger needle number predicted for longer RTOG resolution. Higher urethral base V100 predicted for RTOG > or =2 toxicity. CONCLUSIONS: Radiation dose to the urethral base, larger PUTV, and needle number, predicted for increased urinary toxicity after prostate brachytherapy. Correlation between urinary morbidity and urethral base dosimetry may reflect a large variation in urethral dose observed at the prostate base.
PURPOSE: To determine whether segmental urethral dosimetry is predictive for the degree of urinary morbidity after prostate brachytherapy in patients with no urinary symptoms before prostate brachytherapy. METHODS AND MATERIALS: Between May 2000 and November 2005, 1,107 patients underwent iodine-125 monotherapy with urethral sparing techniques. A total of 166 patients fulfilled the selection criteria: baseline (International Prostate Symptom Score) IPSS < or =5, no androgen deprivation therapy, and prostate ultrasound planning volumes (PUTV) <45 mL. The median follow-up was 44 months. Urinary morbidity was defined by maximum increase in IPSS, time to IPSS resolution, maximum Radiation Therapy Oncology Group (RTOG) score, time to RTOG resolution, and urinary retention. Surrogate deviated urethra was contoured and doses calculated at the base, mid-prostate, apex, and urogenital diaphragm. Univariate and multivariate analysis was used to evaluate urethral and prostate dosimetry, age, PUTV, and number of needles for their association with urinary morbidity. RESULTS: Urethral dose was fairly constant in all urethra segments except prostate base, where the variation in does was large. On multivariate analysis, higher urethral base D50, V100, and larger PUTV were predictive for higher maximum increase in IPSS. Higher urethral base V100 and larger PUTV predicted for prolonged IPSS resolution. Higher urethral base D50 and larger needle number predicted for longer RTOG resolution. Higher urethral base V100 predicted for RTOG > or =2 toxicity. CONCLUSIONS: Radiation dose to the urethral base, larger PUTV, and needle number, predicted for increased urinary toxicity after prostate brachytherapy. Correlation between urinary morbidity and urethral base dosimetry may reflect a large variation in urethral dose observed at the prostate base.
Authors: Kazuma Kobayashi; Naoya Murakami; Kana Takahashi; Koji Inaba; Hiroshi Igaki; Ryuji Hamamoto; Jun Itami Journal: In Vivo Date: 2021 Jan-Feb Impact factor: 2.155
Authors: Adam Ferro; Hee Joon Bae; Gayane Yenokyan; Yi Le; Todd McNutt; Omar Mian; Carol Gergis; Chloe Haviland; Theodore L DeWeese; Daniel Y Song Journal: Brachytherapy Date: 2017-11-23 Impact factor: 2.362
Authors: Lara Hathout; Michael R Folkert; Marisa A Kollmeier; Yoshiya Yamada; Gil'ad N Cohen; Michael J Zelefsky Journal: Int J Radiat Oncol Biol Phys Date: 2014-10-01 Impact factor: 7.038
Authors: Kazuma Kobayashi; Naoya Murakami; Kana Takahashi; Koji Inaba; Hiroshi Igaki; Ryuji Hamamoto; Jun Itami Journal: In Vivo Date: 2019 Nov-Dec Impact factor: 2.155