title: Predicting the resected tissue weight from a digital rectal examination and total prostate specific antigen level before transurethral resection of the prostate.
abstract: OBJECTIVE
  To determine the use of the prostate specific antigen (PSA) level and digital rectal examination (DRE) findings to estimate the resected tissue weight (RTW) before transurethral resection of the prostate (TURP).
  
  
  METHODS
  We retrospectively analysed 983 patients who underwent TURP between December 2006 and December 2012. The primary outcome was the RTW required for clinical improvement, and was not associated with re-intervention. Age, PSA level, body mass index (BMI) and DRE findings were correlated and modelled with the RTW. The DRE result was defined as DREa (small vs. large) or DREb (small vs. moderate vs. large) according to the surgeon's report. Equations to calculate RTW were developed and tested using receiver operating characteristic (ROC) curve analyses.
  
  
  RESULTS
  There were significant correlations between PSA level (r = 0.4, P < 0.001) and RTW, whilst BMI and age showed weak correlations. The median (range) RTW was 45 (7-60) vs. 15 (6-60) g for small vs. large prostates (DREa) (P < 0.001), respectively. Similarly, the median (range) RTW was 11 (6-59) vs. 26.2 (6-60) vs. 42 (7-60) g in small vs. moderate vs. large prostates (DREb) (P < 0.001), respectively. Using PSA level and DREb (model 3) there was a significantly better ability to estimate RTW than using PSA and DREa (model 2) or PSA alone (model 1) based on ROC curve analyses. The equation developed by model 3 (RTW = 1.2 + (1.13 × PSA) + (DREb × 9.5)) had a sensitivity and specificity of 82% and 71% for estimating a RTW of >30 g, and 84% and 63% for estimating a RTW of >40 g, respectively.
  
  
  CONCLUSIONS
  The PSA level and DRE findings can be used to predict the RTW before TURP.
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Harraz
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Assmy
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Tharwat
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Elshal
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Ahmed R
authors.initials: AR
authors.lastname: El-Nahas
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Tamer S
authors.initials: TS
authors.lastname: Barakat
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Mohamed M
authors.initials: MM
authors.lastname: Elsaadany
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: Samer
authors.initials: S
authors.lastname: El-Halwagy
authors.affiliation: Urology and Nephrology Center, Mansoura University, Mansoura, Egypt.
authors.forename: El Housseiny I
authors.initials: el HI
authors.lastname: Ibrahiem
keywords: AUC, area under the curve; BMI, body mass index; DRE; PSA; PV, prostate volume; Prostate volume; ROC, receiver operating characteristic; RTW, resected tissue weight; Resected tissue weight; TURP