title: Indenter study: associations between prostate elasticity and lower urinary tract symptoms.
abstract: OBJECTIVE
  To investigate the associations between prostate elasticity and lower urinary tract symptoms (LUTS).
  
  
  METHODS
  From August 2009 to December 2009, 48 patients with no history of neoadjuvant therapy or previous prostate surgery who underwent robot-assisted radical prostatectomy were included in this study. A novel palpation system was used to measure the tissue elasticity of the prostate specimens. The elasticity of the prostate was defined as the mean elastic modulus (kilopascals [kPa]) of 21 sites from the posterior surface of prostate. All patients completed an International Prostate Symptoms Score questionnaire before surgery, and LUTS was defined as an International Prostate Symptoms Score total of ≥8. Significant voiding symptoms were identified by a score of ≥5 on the basis of patient responses to 4 questions (Q1, Q3, Q5, and Q6), and storage symptoms were identified by a score ≥4 on the basis of patient responses to 3 questions (Q2, Q4, and Q7).
  
  
  RESULTS
  The median elastic modulus of the prostate was 20.8 kPa (interquartile range 15.6-22.9), and the LUTS incidences and voiding symptoms were significantly higher in patients with an elastic modulus >20 kPa. The multivariate logistic regression results indicated that a higher elastic modulus (as a continuous variable) was independently associated with voiding symptoms (odds ratio 1.18, P = .038) after controlling for age and prostate volume. However, the elastic modulus was not independently associated with LUTS or storage symptoms.
  
  
  CONCLUSIONS
  Patients with greater prostate stiffness are more likely to develop LUTS. Specifically, prostate elasticity was independently associated with voiding symptoms.
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea; Department of Urology, Ewha Womans University Mokdong Hospital, Seoul, Republic of Korea.
authors.forename: Kwang Hyun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Wellness Technology R&D Group, Korea Institute of Industrial Technology, Ansan, Republic of Korea.
authors.forename: Bummo
authors.initials: B
authors.lastname: Ahn
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sey Kiat
authors.initials: SK
authors.lastname: Lim
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Woong Kyu
authors.initials: WK
authors.lastname: Han
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jang Hwan
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: khrha@yuhs.ac.
authors.forename: Koon Ho
authors.initials: KH
authors.lastname: Rha
authors.affiliation: Department of Mechanical Engineering, School of Mechanical, Aerospace and Systems Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Jung
authors.initials: J
authors.lastname: Kim
mesh_terms: D000368:Aged; D055119:Elastic Modulus / Q000502:physiology*; D006801:Humans; D059411:Lower Urinary Tract Symptoms / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000503:physiopathology*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000601:surgery*; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires