Interexaminer reliability of transrectal ultrasound for estimating prostate volume.

PURPOSE: We investigated the interexaminer reliability of transrectal ultrasound measurement of total prostate and transition zone volume among 3 examiners with various levels of experience. MATERIALS AND METHODS: A total of 121 patients 39 to 82 years old (average plus or minus standard deviation 60.7 +/- 10.3) from a single urology clinic volunteered to participate. Patients with prostate cancer, previous prostate surgery or recent invasive prostatic examination were excluded from study. Each individual was examined independently by each of 3 examiners with various levels of experience, including an attending urologist, a PGY-2 resident in the second year of general surgery before urology training and a PGY-4 resident in the second year of urology training. Transrectal ultrasound was performed in each case by each examiner in pre-specified random order. RESULTS: Mean total prostate and transition zone volume was 35.9 +/- 27.2 and 15.6 +/- 18.8 ml., respectively. Interexaminer agreement or reliability of the ultrasound measurements was high for total prostate and transition zone volume (intraclass correlation 0.96, 95% confidence interval [CI] 0.95 to 0.97 and 0.93, 95% CI 0.90 to 0.95, respectively). For individual prostatic dimensions reliability estimates were 0.78 to 0.86, while for transition zone dimensions reliability was 0.85 to 0.90. Total prostate volume reliability was higher for prostate volume greater than 40 ml. versus smaller prostates (intraclass correlation 0.95, 95% CI 0.90 to 0.97 versus 0.77, 95% CI 0.67 to 0.84). Mean differences in transrectal ultrasound measurements by different examiners were highest for the resident with least experience. CONCLUSIONS: The reliability of transrectal ultrasound measured total prostate and transition zone volume is high for examiners with different levels of experience at this institution. Reliability in patients without prostate cancer appears to be better for larger volume prostates and for examiners with more experience.

Interexaminer reliability and validity of a three-dimensional model to assess prostate volume by digital rectal examination.

OBJECTIVES: To evaluate the interexaminer reliability and accuracy compared with transrectal ultrasound (TRUS) of a three-dimensional (3D) model and other scales to improve the estimation of prostate volume by digital rectal examination (DRE). METHODS: Volunteers from a urology clinic (n = 121) were examined independently by three examiners with different levels of experience in randomized order. During DRE, the examiners estimated the prostate size in increments of 5 g, using various rating scales and a 3D sizing model, without access to the findings of the other investigators. TRUS was then performed by each examiner. RESULTS: The 121 volunteers were 39 to 82 years old, with a mean +/- SD total TRUS prostate size of 35.9 +/- 27.2 g. The DRE size estimates ranged from 15 to 100 g across all examiners and patients. The interexaminer reliability across examiners for the best DRE prostate size estimates (in grams) was 0.78 (95% confidence interval 0.70 to 0.84), and the correlation coefficients (r(s)) with the TRUS volume ranged from 0.61 to 0.72 for the three examiners. A 3D model showed good reliability (intraclass correlation coefficient 0.86, 95% confidence interval 0.75 to 0.93), and correlated well with the TRUS volume (r(s) = 0.67 to 0.75). Other scales showed fair reliability (0.58 to 0.68) and correlated with the TRUS measurements (0.57 to 0.67). The area under the receiver operating characteristic curve to identify prostate volumes greater than 40 g ranged from 0.78 to 0.90 for DRE estimates (in grams) and 0.69 to 0.89 for the 3D model. CONCLUSIONS: DRE size estimates and TRUS volume were moderately to highly correlated in men without prostate cancer. A 3D sizing model showed comparable reliability and correlation with TRUS. Although the DRE estimates generally tend to underestimate the TRUS-measured prostate volume, these tools may be useful in identifying men with enlarged prostate glands.

The so-called "placebo effect" in benign prostatic hyperplasia treatment trials represents partially a conditional regression to the mean induced by censoring.

OBJECTIVES: To study the variability of assessment instruments (symptom questionnaires and flow rate recordings) in healthy volunteers during repeat administration in short intervals. To study the effect of inclusion criteria-based censoring of patients during screening for benign prostatic hyperplasia (BPH) treatment trials on the outcome of subsequent tests. METHODS: One hundred forty-five male volunteers without known prostatic diseases with a mean age of 52 years (range 23 to 83) were given the American Urological Association (AUA) Symptom Index (SI), BPH Impact Index (II). Quality of Life (QOL) score, and a flow rate recording twice 10 to 20 days apart without any healthcare intervention. Data were collected and analyzed after typical BPH trial criteria were applied to the first test, and patients who did not "qualify" were censored. RESULTS: Good correlation exists between two closely spaced administrations of the AUA SI, BPH II, QOL score, and flow rate recordings in healthy male volunteers with correlation coefficients between 0.73 and 0.89. Censoring patients and excluding them from the analysis of the second test based on typical BPH trial criteria induces a regression to the mean phenomenon, which results in an artificial improvement in these outcome parameters. The magnitude of the improvement increases as the selection and censoring criteria tighten. The mean differences between the first and second test range from 1.4 to 1.7 mL/s for the peak flow rate, from -1.0 to -1.4 for the AUA SI, and from -0.4 to -0.8 for the BPH II. All these differences induced solely by censoring with resulting regression to the mean are statistically significant. CONCLUSIONS: Censoring of patients based on inclusion and exclusion criteria is typical for BPH treatment trials. One of the under-recognized effects of censoring is a regression to the mean, which leads to an apparent improvement in the outcome parameters assessed. In both placebo or sham-controlled trials, as well as in clinical series without controls, one must keep this effect and its relative magnitude in mind, and interpret the data from such trials with appropriate caution.

Microwave thermotherapy for benign prostatic hyperplasia with the Dornier Urowave: results of a randomized, double-blind, multicenter, sham-controlled trial.

OBJECTIVES: To study the efficacy and safety of a new transurethral microwave thermotherapy device (the Urowave) in the treatment of men with clinical benign prostatic hyperplasia (BPH) in a randomized, double-blind, sham-controlled trial. METHODS: A total of 220 patients (mean age 66.2 years) with clinical BPH, an American Urological Association symptom index (AUA SI) of 13 points or more, and a peak flow rate of 12 mL/s or less were enrolled and randomized 2:1 for active versus sham treatment. All treatments were conducted as an outpatient procedure under local anesthesia, with oral sedation and analgesia only. Patients were followed up at 1 week and 1, 3, and 6 months after treatment. RESULTS: The treatments were well tolerated, and no patient received general or spinal anesthesia. The AUA SI dropped from 23.6 to 12.7 points at 6 months (P < 0.05) in the active group and from 23.9 to 18.0 points in the sham-treated group (P < 0.05, between-group difference). Statistically significant improvements were also noted for peak flow rate (7.7 to 10.7 mL/s at 6 months for active treatment, 8.1 to 9.8 mL/s for sham treatment, P < 0.05, between-group difference) and for average flow rate. A decrease in AUA SI of more than 30% was achieved in 72% versus 38% of patients (active versus sham treatment, respectively) and more than 50% in 50% versus 19% of patients. In general, active Urowave-treated patients perceived "a lot" of improvement, whereas sham-treated patients perceived "a little" to "some" improvement. More of the actively treated patients had dysuria and urgency after treatment, and ejaculatory dysfunction (e.g., hematospermia) was more common in actively treated patients as well. Secondary urinary retention after removal of the catheter occurred in 8 patients (5.4%). CONCLUSIONS: The Dornier Urowave transurethral microwave thermotherapy device for treatment of clinical BPH is effective in decreasing symptoms and bother and improving quality of life and flow rate and is superior to sham treatment. Patients perceive a great deal of improvement, independent of their baseline symptom severity. Adverse events are in general transient and mild in nature. Extended follow-up is necessary to document long-term durability of improvements.

Safety and efficacy of the Alexandrite laser for the treatment of renal and ureteral calculi.

OBJECTIVES: To assess the safety and efficacy of the Alexandrite laser for intracorporeal lithotripsy of renal and ureteral stones in conjunction with ureterorenoscopy or percutaneous nephrostolithotomy. METHODS: We retrospectively analyzed the records of 137 patients with 169 calculi in 143 renoureteral units who were treated with the Alexandrite laser via a retrograde (91.5%) or antegrade (8.5%) endoscopic approach. RESULTS: Adequate intraoperative fragmentation of the stone was observed in 88.8% of the cases. No intraoperative complications were attributable to the laser. At a mean follow-up of 34 days, the overall stone-free rate was 74.4%. The stone-free rate for ureteral stones (n = 115) was 80%, whereas the stone-free rate for renal stones (n = 22) was only 44%. In the best subgroup of ureteral stones (10 mm or less in the distal ureter), the stone-free rate was 97.4%. CONCLUSIONS: The Alexandrite laser is a safe modality for intracorporeal lithotripsy and is highly effective for ureteral stones less than 10 mm in size.

Correlation between prostate size estimated by digital rectal examination and measured by transrectal ultrasound.

OBJECTIVES: To correlate prostate size estimates performed by single or multiple examiners through digital rectal examination (DRE) with volume measured by transrectal ultrasound (TRUS) and to propose measures for predicting prostate volume using DRE estimates in clinical settings. METHODS: Data from four sources were analyzed: (1) the Olmsted County community study of 397 patients examined by a single urology nurse, with TRUS measurements done by multiple examiners; (2) a community study in Stirling, Scotland, involving 480 patients with DRE and TRUS performed by one urologist; (3) baseline data from the Veterans Affairs Cooperative Study No. 359 in 1222 patients with DRE and TRUS measurements by multiple personnel at 31 centers; and (4) a clinical series of 100 men with DRE and TRUS by a single urologist. RESULTS: DRE estimates and TRUS volumes were significantly correlated (r = 0.4 to 0.9), but prostate size was underestimated by 25% to 55% for men with a prostate volume over 40 mL, depending on the study, with greater variability for studies involving multiple examiners. In one study that assessed prostate dimensions by DRE, posterior surface area (SA) correlated with overall TRUS volume (r = 0.4). According to receiver operating characteristic curves, SA showed a 70% and 76% chance of correctly identifying men with prostate volume greater than 30 or 40 mL, respectively; those with larger prostates were best distinguished by SA greater than 7 cm2 (sensitivity greater than 0.74, specificity greater than 0.50). CONCLUSIONS: DRE underestimates prostate size, particularly if TRUS volume is greater than 30 mL. However, DRE estimates may help identify prostates likely to be larger than certain cutpoints by TRUS. Posterior SA may be useful as a preliminary assessment when prostate size is an important predictor of therapeutic response.