title: Obstructive voiding symptoms following stereotactic body radiation therapy for prostate cancer.
abstract: BACKGROUND
  Obstructive voiding symptoms (OVS) are common following prostate cancer treatment with radiation therapy. The risk of urinary retention (UR) following hypofractionated radiotherapy has yet to be fully elucidated. This study sought to evaluate OVS and UR requiring catheterization following SBRT for prostate cancer.
  
  
  METHODS
  Patients treated with SBRT for localized prostate cancer from February 2008 to July 2011 at Georgetown University were included in this study. Treatment was delivered using the CyberKnife® with doses of 35 Gy-36.25 Gy in 5 fractions. UR was prospectively scored using the CTCAE v.3. Patient-reported OVS were assessed using the IPSS-obstructive subdomain at baseline and at 1, 3, 6, 9, 12, 18 and 24 months. Associated bother was evaluated via the EPIC-26.
  
  
  RESULTS
  269 patients at a median age of 69 years received SBRT with a median follow-up of 3 years. The mean prostate volume was 39 cc. Prior to treatment, 50.6% of patients reported moderate to severe lower urinary track symptoms per the IPSS and 6.7% felt that weak urine stream and/or incomplete emptying were a moderate to big problem. The 2-year actuarial incidence rates of acute and late UR ≥ grade 2 were 39.5% and 41.4%. Alpha-antagonist utilization rose at one month (58%) and 18 months (48%) post-treatment. However, Grade 3 UR was low with only 4 men (1.5%) requiring catheterization and/or TURP. A mean baseline IPSS-obstructive score of 3.6 significantly increased to 5.0 at 1 month (p < 0.0001); however, it returned to baseline in 92.6% within a median time of 3 months. Late increases in OVS were common, but transient. Only 7.1% of patients felt that weak urine stream and/or incomplete emptying was a moderate to big problem at two years post-SBRT (p = 0.6854).
  
  
  CONCLUSIONS
  SBRT treatment caused an acute increase in OVS which peaked within the first month post-treatment, though acute UR requiring catheterization was rare. OVS returned to baseline in > 90% of patients within a median time of three months. Transient Late increases in OVS were common. However, less than 10% of patients felt that OVS were a moderate to big problem at two years post-SBRT.
authors: W Tristram
authors: WT
authors: Arscott
authors: Leonard N
authors: LN
authors: Chen
authors: Nathan
authors: N
authors: Wilson
authors: Aditi
authors: A
authors: Bhagat
authors: Joy S
authors: JS
authors: Kim
authors: Rudy A
authors: RA
authors: Moures
authors: Thomas M
authors: TM
authors: Yung
authors: Siyuan
authors: S
authors: Lei
authors: Brian T
authors: BT
authors: Collins
authors: Keith
authors: K
authors: Kowalczyk
authors: Simeng
authors: S
authors: Suy
authors: Anatoly
authors: A
authors: Dritschilo
authors: John H
authors: JH
authors: Lynch
authors: Department of Radiation Medicine, Georgetown University Hospital, 3800 Reservoir Road, NW, Washington, DC 20007, USA. SPC9@gunet.georgetown.edu.
authors: Sean P
authors: SP
authors: Collins
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004219:District of Columbia / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D015995:Prevalence; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011788:Quality of Life; D016634:Radiosurgery / Q000009:adverse effects*; D011879:Radiotherapy Dosage; D001748:Urinary Bladder Neck Obstruction / Q000453:epidemiology* / Q000209:etiology; D016055:Urinary Retention / Q000453:epidemiology* / Q000209:etiology