Prostate MRI/ultrasound fusion and biopsy yield

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Background: MRI has been shown useful for identifying targets after negative biopsy. We purport to show the advantage of realtime fusion of MRI data with ultrasound for initial or repeat TRUS biopsy compared with sextant biopsy.

Methods: An IRB-approved prospective study of 57 consecutive men with diffusion weighted imaging and dynamic contrast enhanced (DCE) perfusion in addition to T2-weighted imaging on a Siemens Magnetom 3.0 T Trio using an external phased array coil had targets chosen based on decreased T2 signal with abnormally restricted diffusion or abnormal DCE by a uroradiologist with 6 years experience in prostate imaging, followed by ultrasound-guided biopsies using MR/ultrasound fusion software (Artemis, Eigen) in addition to standard 12-core sextant biopsies.

Results: In 56 patients, 101 suspicious areas were identified by MRI; 28 positive targets were found in 22 men, including 19 Gleason 3+3 (68%), 8 Gleason 3+4 (29%), and one with HGPIN (3%). In 28 patients, neither targets nor systematic cores were positive, and in one patient no targets were identified. Positive cores were found in 12 patients only on targets only including 6 Gleason 3+4. One patient was “upstaged;” the target was Gleason 3+4 whereas the positive systematic cores were Gleason 3+3. In 8 patients the Gleason score of systematic and targeted cores was identical, 2 Gleason 3+4 and 6 Gleason 3+3. In 7 patients systematic cores were Gleason 3+3 with negative targets, all less than 4 mm and less than 25 percent of the core. Fisher exact test showed a trend to significance, p = 0.06 for any cancer identified, and p = 0.03 for Gleason 3+4 disease.

Conclusions: The improved accuracy of MRI-TRUS fusion biopsies may be able to replace systematic biopsies, avoiding the discomfort and risks associated, and improve diagnostic yield, and improve confidence for patients with a small amount of low-grade cancer who opt for active surveillance.

Clinical application of a 3D ultrasound-guided prostate biopsy system

OBJECTIVES

Prostate biopsy (Bx) has for 3 decades been performed in a systematic, but blind fashion using 2D ultrasound (US). Herein is described the initial clinical evaluation of a 3D Bx tracking and targeting device (Artemis; Eigen, Grass Valley, CA). Our main objective was to test accuracy of the new 3D method in men undergoing first and follow-up Bx to rule out prostate cancer (CaP).

MATERIALS AND METHODS

Patients in the study were men ages 35-87 years (66.1 ± 9.9), scheduled for Bx to rule out CaP, who entered into an IRB-approved protocol. A total of 218 subjects underwent conventional trans-rectal US (TRUS); the tracking system was then attached to the US probe; the prostate was scanned and a 3D reconstruction was created. All Bx sites were visualized in 3D and tracked electronically. In 11 men, a pilot study was conducted to test ability of the device to return a Bx to an original site. In 47 men, multi-parametric 3 Tesla MRI, incorporating T2-weighted images, dynamic contrast enhancement, and diffusion-weighted imaging, was performed in advance of the TRUS, allowing the stored MRI images to be fused with real-time US during biopsy. Lesions on MRI were delineated by a radiologist, assigned a grade of CaP suspicion, and fused into TRUS for biopsy targeting.

RESULTS

3D Bx tracking was completed successfully in 180/218 patients, with a success rate approaching 95% among the last 50 men. Average time for Bx with the Artemis device was 15 minutes with an additional 5 minutes for MRI fusion and Bx targeting. In the tracking study, an ability to return to prior Bx sites (n=32) within 1.2 ± 1.1 mm SD was demonstrated and was independent of prostate volume or location of Bx site. In the MRI fusion study, when suspicious lesions were targeted, a 33% Bx-positivity rate was found compared with a 7% positivity rate for systematic, nontargeted Bx (19/57 cores vs. 9/124 cores, P=0.03).

CONCLUSION

Use of 3D tracking and image fusion has the potential to transform MRI into a clinical tool to aid biopsy and improve current methods for diagnosis and follow-up of CaP.

Effect of testosterone replacement therapy on prostate tissue in men with late-onset hypogonadism: a randomized controlled trial

CONTEXT

Prostate safety is a primary concern when aging men receive testosterone replacement therapy (TRT), but little information is available regarding the effects of TRT on prostate tissue in men.

OBJECTIVE

To determine the effects of TRT on prostate tissue of aging men with low serum testosterone levels.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind, placebo-controlled trial of 44 men, aged 44 to 78 years, with screening serum testosterone levels lower than 300 ng/dL (<10.4 nmol/L) and related symptoms, conducted at a US community-based research center between February 2003 and November 2004.

INTERVENTION

Participants were randomly assigned to receive 150 mg of testosterone enanthate or matching placebo intramuscularly every 2 weeks for 6 months.

MAIN OUTCOME MEASURES

The primary outcome measure was the 6-month change in prostate tissue androgen levels (testosterone and dihydrotestosterone). Secondary outcome measures included 6-month changes in prostate-related clinical features, histology, biomarkers, and epithelial cell gene expression.

RESULTS

Of the 44 men randomized, 40 had prostate biopsies performed both at baseline and at 6 months and qualified for per-protocol analysis (TRT, n = 21; placebo, n = 19). Testosterone replacement therapy increased serum testosterone levels to the mid-normal range (median at baseline, 282 ng/dL [9.8 nmol/L]; median at 6 months, 640 ng/dL [22.2 nmol/L]) with no significant change in serum testosterone levels in matched, placebo-treated men. However, median prostate tissue levels of testosterone (0.91 ng/g) and dihydrotestosterone (6.79 ng/g) did not change significantly in the TRT group. No treatment-related change was observed in prostate histology, tissue biomarkers (androgen receptor, Ki-67, CD34), gene expression (including AR, PSA, PAP2A, VEGF, NXK3, CLU [Clusterin]), or cancer incidence or severity. Treatment-related changes in prostate volume, serum prostate-specific antigen, voiding symptoms, and urinary flow were minor.

CONCLUSIONS

These preliminary data suggest that in aging men with late-onset hypogonadism, 6 months of TRT normalizes serum androgen levels but appears to have little effect on prostate tissue androgen levels and cellular functions. Establishment of prostate safety for large populations of older men undergoing longer duration of TRT requires further study. Trial Registration clinicaltrials.gov Identifier: NCT00161304.

APTIMA PCA3 molecular urine test: development of a method to aid in the diagnosis of prostate cancer

BACKGROUND

Prostate cancer gene 3 (PCA3) encodes a prostate-specific mRNA that has shown promise as a prostate cancer diagnostic tool. This report describes the characterization of a prototype quantitative PCA3-based test for whole urine.

METHODS

Whole-urine specimens were collected after digital rectal examination from 3 groups: men scheduled for prostate biopsy (n = 70), healthy men (<45 years of age with no known prostate cancer risk factors; n = 52), and men who had undergone radical prostatectomy (n = 21). PCA3 and prostate-specific antigen (PSA) mRNAs were isolated, amplified, and quantified by use of Gen-Probe DTS400 Systems. Prostate biopsy results were correlated with the PCA3/PSA mRNA ratio, and PSA mRNA concentrations were used to normalize PCA3 signals and confirm the yield of prostate-specific RNA. Assay precision, specimen stability, and mRNA yield were also evaluated.

RESULTS

The specimen informative rate (fraction of specimens yielding sufficient RNA for analysis) was 98.2%. In this clinical research study, ROC curve analysis of prebiopsy specimens yielded an area under the curve of 0.746; sensitivity was 69% and specificity 79%. Serum PSA assay specificity was 28% for this same group. PCA3 and PSA mRNAs were undetectable in postprostatectomy specimens except for one man with recurrent prostate cancer. Assay interrun CVs were < or =12%. Both mRNAs were stable in processed urine up to 5 days at 4 degrees C and after 5 freeze-thaw cycles.

CONCLUSION

The APTIMA PCA3 assay combines simple specimen processing with precise assays and existing instruments and could add specificity to the current algorithm for prostate cancer diagnosis.

Saw palmetto alters nuclear measurements reflecting DNA content in men with symptomatic BPH: evidence for a possible molecular mechanism

OBJECTIVES

To examine the nuclear chromatin characteristics of epithelial cells, looking for an SPHB-mediated effect on nuclear DNA structure and organization. Saw palmetto herbal blend (SPHB) causes contraction of prostate epithelial cells and suppression of tissue dihydrotestosterone levels in men with symptomatic benign prostatic hyperplasia, but a fundamental mechanism remains unknown.

METHODS

A 6-month randomized trial, comparing prostatic tissue of men treated with SPHB (n = 20) or placebo (n = 20), was performed. At baseline, the two groups were similar in age (65 versus 64 years), symptoms (International Prostate Symptom Score 18 versus 17), uroflow (maximal urinary flow rate 10 versus 11 mL/s), prostate volume (59 versus 58 cm(3)), prostate-specific antigen (4.2 versus 2.7 ng/mL), and percentage of epithelium (17% versus 16%). Prostatic tissue was obtained by sextant biopsy before and after treatment. Five-micron sections were Feulgen stained and quantitatively analyzed using the AutoCyte QUIC-DNA imaging system. Images were captured from 200 randomly selected epithelial cell nuclei, and 60 nuclear morphometric descriptors (NMDs) (eg, size, shape, DNA content, and textural features) were determined for each nucleus. Logistic regression analysis was used to assess the differences in the variances of the NMDs between the treated and untreated prostate epithelial cells.

RESULTS

At baseline, the SPHB and placebo groups had similar NMD values. After 6 months of placebo, no significant change from baseline was found in the NMDs. However, after 6 months of SPHB, 25 of the 60 NMDs were significantly different compared with baseline, and a multivariate model for predicting treatment effect using 4 of the 25 was created (P <0.001). The multivariate model had an area under the receiver operating characteristic curve of 94% and an accuracy of 85%.

CONCLUSIONS

Six months of SPHB treatment appears to alter the DNA chromatin structure and organization in prostate epithelial cells. Thus, a possible molecular basis for tissue changes and therapeutic effect of the compound is suggested.

Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia

PURPOSE

We tested the effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia (BPH) via a randomized, placebo controlled trial.

MATERIALS AND METHODS

We randomized 44 men 45 to 80 years old with symptomatic BPH into a trial of a saw palmetto herbal blend versus placebo. End points included routine clinical measures (symptom score, uroflowmetry and post-void residual urine volume), blood chemistry studies (prostate specific antigen, sex hormones and multiphasic analysis), prostate volumetrics by magnetic resonance imaging, and prostate biopsy for zonal tissue morphometry and semiquantitative histology studies.

RESULTS

Saw palmetto herbal blend and placebo groups had improved clinical parameters with a slight advantage in the saw palmetto group (not statistically significant). Neither prostate specific antigen nor prostate volume changed from baseline. Prostate epithelial contraction was noted, especially in the transition zone, where percent epithelium decreased from 17.8% at baseline to 10.7% after 6 months of saw palmetto herbal blend (p <0.01). Histological studies showed that the percent of atrophic glands increased from 25. 2% to 40.9% after treatment with saw palmetto herbal blend (p <0.01). The mechanism of action appeared to be nonhormonal but it was not identified by tissue studies of apoptosis, cellular proliferation, angiogenesis, growth factors or androgen receptor expression. We noted no adverse effects of saw palmetto herbal blend. When the study was no longer blinded, 41 men elected to continue therapy in an open label extension.

CONCLUSIONS

Saw palmetto herbal blend appears to be a safe, highly desirable option for men with moderately symptomatic BPH. The secondary outcome measures of clinical effect in our study were only slightly better for saw palmetto herbal blend than placebo (not statistically significant). However, saw palmetto herbal blend therapy was associated with epithelial contraction, especially in the transition zone (p <0.01), indicating a possible mechanism of action underlying the clinical significance detected in other studies.

Use of a shape-memory alloy (nitinol) in a removable prostate stent

An easily removable prostate stent would be useful in various clinical situations but is not currently available. Thus, we studied the safety, tolerability, and ease of removal of a nitinol (nickel-titanium alloy) prostate stent in 10 men with symptomatic benign prostatic hyperplasia. The circular-coil stent becomes hourglass in shape following deployment, with the narrowest diameter approximately 35F. A working hypothesis was that the temperature-sensitive shape memory of nitinol would allow for its easy removal vis-à-vis other available stents. Using several modifications of a prototype insertion device, we found that the nitinol stents were easily inserted, retained their shape during retention periods of 1 to 4 weeks, caused no gross tissue reaction, and were removed easily with gentle traction after in situ cooling with iced saline lavage. Stent migration was observed in two patients, but otherwise, the stents were well tolerated. Nitinol prostate stents appear to fulfill a theoretical promise of being biologically inert, "superelastic," and pliable when cooled, allowing for easy removal. Further clinical investigation appears warranted.

Long-term effects of finasteride on prostate tissue composition

OBJECTIVES

To determine the long-term effects of finasteride treatment on prostate tissue composition; to relate these effects to clinical outcomes; and to test the hypothesis that finasteride exerts a selective or preferential action on the transition zone.

METHODS

Nineteen men with symptomatic benign prostatic hyperplasia (BPH) who completed a 6-month double-blind trial of finasteride were enrolled in a 24-month open-label extension study of drug responders. Magnetic resonance imaging and prostate biopsy for morphometric analysis were performed together 70 times: at baseline (n = 19), after treatment periods of intermediate duration (6 to 18 months, n = 32), and after long-term drug treatment (24 to 30 months, n = 19). At baseline, prostate volume averaged 51 cc, of which 57% was transition zone.

RESULTS

Decreases in symptom score, dihydrotestosterone and prostate-specific antigen levels, and prostate volume occurred at 6 months (P <0.01), stabilized, and were maintained without further long-term decreases. Prostate epithelium contracted progressively from baseline (19.2% tissue composition; 6.0-cc volume; 3.2 stroma/epithelial ratio) to intermediate (12.5%, 3.3 cc, and 5.6, respectively) to long-term treatment (6.4%, 2.0 cc, and 17.4, respectively, P <0.01 for all). Percent epithelial contraction was similar in the peripheral and transition zones (P = NS). The transition zone remained a relatively constant proportion (53% to 58%) of whole-prostate volume from baseline to long-term observation.

CONCLUSIONS

Long-term finasteride treatment (24 to 30 months) results in a marked involution of the prostate epithelium, which continues to progress for many months after clinical effects stabilize. The effect on the epithelium is similar in the peripheral and transition zones for both morphometric and volumetric changes. Progressive contraction of the prostate epithelium appears to constitute the underlying mechanism for sustained action of finasteride.

Treatment of erectile dysfunction with sildenafil

OBJECTIVES

To determine the efficacy of sildenafil for the treatment of erectile dysfunction (ED) in a clinical practice setting; to evaluate the correlation between patient and partner perceptions of treatment outcomes; and to assess the relation between the severity of ED and response to treatment.

METHODS

Among the first 100 men to receive sildenafil in a urology practice setting, 74 (mean + SD age 64+/-11 years) completed a validated sexual function questionnaire (International Index of Erectile Function [IIEF]) before and after a 4 to 6-week treatment period. A modified version of the same questionnaire was independently completed by partners. ED was categorized into a severity class of I to IV.

RESULTS

Sildenafil treatment improved erections by 71% to 95%, according to responses in key IIEF questions 3 and 4. Overall, 57 (77%) of 74 patients desired to continue treatment after the test period. Patient score on the IIEF was correlated with partner score on the modified questionnaire before and after treatment (r = 0.67 to 0.81, P <0.01). IIEF scores were reflected in a simple severity classification system. Men with the best preservation of erections (severity class I) exhibited the best responses to sildenafil, whereas men with no erections (severity class IV) were much less likely to respond to the drug and desire continuation of treatment (P <0.01). Patients with a radical prostatectomy were relatively refractory to sildenafil, except for 2 of 5 who had undergone a nerve-sparing operation.

CONCLUSIONS

In clinical practice, sildenafil is an effective treatment of ED, according to partner-validated questionnaire responses; and the results of treatment are predictable with an ED severity classification system.

Three-dimensional ultrasound device for rapid determination of bladder volume

OBJECTIVES

We sought to assess the accuracy, reliability, and clinical utility of the noninvasive determination of bladder volume using an automated, compact three-dimensional (3-D) ultrasound device.

METHODS

We prospectively tested 249 adult outpatients for accuracy (n = 182), by comparing scan versus catheter volumes, or reliability (n = 67), by comparing the scan readings of two independent observers. Two models of the bladder scan device were tested (BVI-2500, 1994 and 1995 models).

RESULTS

Scan and catheter volumes were correlated (y = 1.02x + 12.6, R2 = 0.90, P < 0.001) across a range of zero to 1015 cc, regardless of which machine model was used. Scan volume underestimated catheter volume by an average of 10 cc in men and 20 cc in women. If a scan-predicted volume of 100 cc or greater were used as a cutpoint for clinical importance, the device exhibited a sensitivity of 97%, a specificity of 91%, and an overall accuracy of 94%. These results were not affected by age, gender, height, weight, diagnosis, uterine presence/prostate size, or user experience. The two observers, one a graduate physician and the other a college student, achieved essentially the same volume determinations (y = 0.96x + 0.13, R2 = 0.90, P < 0.001).

CONCLUSIONS

Volume determinations obtained with the bladder scan device are accurate and reliable in adult outpatients. A special technician is not required. These results may be attributable to use of automated planimetry and 3-D volumetry, rather than a fixed geometric formula, to custom measure each bladder shape.