Ultrasound guided transrectal core biopsies of the palpably abnormal prostate

Coagulation of human prostate volumes with MRI-controlled transurethral ultrasound therapy: results in gel phantoms

PURPOSE

The feasibility and safety of magnetic resonance imaging (MRI)-controlled transurethral ultrasound therapy were demonstrated recently in a preliminary human study in which a small subvolume of prostate tissue was treated prior to radical prostatectomy. Translation of this technology to full clinical use, however, requires the capability to generate thermal coagulation in a volume up to that of the prostate gland itself. The aim of this study was to investigate the parameters required to treat a full 3D human prostate accurately with a multi-element transurethral applicator and multiplanar MR temperature control.

METHODS

The approach was a combination of simulations (to select appropriate parameters) followed by experimental confirmation in tissue-mimicking phantoms. A ten-channel, MRI-compatible transurethral ultrasound therapy system was evaluated using six human prostate models (average volume: 36 cm(3)) obtained from the preliminary human feasibility study. Real-time multiplanar MR thermometry at 3 T was used to control the spatial heating pattern in up to nine planes simultaneously. Treatment strategies incorporated both single (4.6 or 8.1 MHz) and dual (4.6 and 14.4 MHz) frequencies, as well as maximum acoustic surface powers of 10 or 20 W cm(-2).

RESULTS

Treatments at 4.6 MHz were capable of coagulating a volume equivalent to 97% of the prostate. Increasing power from 10 to 20 W cm(-2) reduced treatment times by approximately 50% with full treatments taking 26 ± 3 min at a coagulation rate of 1.8 ± 0.4 cm(3) min(-1). A dual-frequency 4.6∕14.4 MHz treatment strategy was shown to be the most effective configuration for achieving full human prostate treatment while maintaining good treatment accuracy for small treatment radii. The dual-frequency approach reduced overtreatment close to the prostate base and apex, confirming the simulations.

CONCLUSIONS

This study reinforces the capability of MRI-controlled transurethral ultrasound therapy to treat full prostate volumes in a short treatment time with good spatial targeting accuracy and provides key parameters necessary for the next clinical trial.

Prospective evaluation of an extended 21-core biopsy scheme as initial prostate cancer diagnostic strategy

BACKGROUND

The debate on the optimal number of prostate biopsy core samples that should be taken as an initial strategy is open.

OBJECTIVE

To prospectively evaluate the diagnostic yield of a 21-core biopsy protocol as an initial strategy for prostate cancer (PCa) detection.

DESIGN, SETTING, AND PARTICIPANTS

During 10 yr, 2753 consecutive patients underwent a 21-core biopsy scheme for their first set of biopsy specimens.

INTERVENTION

All patients underwent a standardized 21-core protocol with cores mapped for location.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The PCa detection rate of each biopsy scheme (6, 12, or 21 cores) was compared using a McNemar test. Predictive factors of the diagnostic yield achieved by a 21-core scheme were studied using logistic regression analyses.

RESULTS AND LIMITATIONS

PCa detection rates using 6 sextant biopsies, 12 cores, and 21 cores were 32.5%, 40.4%, and 43.3%, respectively. The 12-core procedure improved the cancer detection rate by 19.4% (p=0.004), and the 21-biopsy scheme improved the rate by 6.7% overall (p<0.001). The six far lateral cores were the most efficient in terms of detection rate. The diagnostic yield of the 21-core protocol was >10% in prostates with volume >70 ml, in men with a prostate-specific antigen level<4 ng/ml, with a prostate-specific antigen density (PSAD) <0.20 ng/ml per gram. A PSAD <0.20 ng/ml per gram was the strongest independent predictive factor of the diagnostic yield offered by the 21-core scheme (p<0.001). The 21-core protocol significantly increased the rate of PCa eligible for active surveillance (62.5% vs 48.4%; p=0.036) than those detected by a 12-core scheme without statistically increasing the rate of insignificant PCa (p=0.503).

CONCLUSIONS

A 21-core biopsy scheme improves significantly the PCa detection rate compared with a 12-core protocol. We identified a cut-off PSAD (0.20 ng/ml per gram) below which an extended 21-core scheme might be systematically proposed to significantly improve the overall detection rate without increasing the rate of detected insignificant PCa.

Investigation of power and frequency for 3D conformal MRI-controlled transurethral ultrasound therapy with a dual frequency multi-element transducer

Transurethral ultrasound therapy uses real-time magnetic resonance (MR) temperature feedback to enable the 3D control of thermal therapy accurately in a region within the prostate. Previous canine studies showed the feasibility of this method in vivo. The aim of this study was to reduce the procedure time, while maintaining targeting accuracy, by investigating new combinations of treatment parameters. Simulations and validation experiments in gel phantoms were used, with a collection of nine 3D realistic target prostate boundaries obtained from previous preclinical studies, where multi-slice MR images were acquired with the transurethral device in place. Acoustic power and rotation rate were varied based on temperature feedback at the prostate boundary. Maximum acoustic power and rotation rate were optimised interdependently, as a function of prostate radius and transducer operating frequency. The concept of dual frequency transducers was studied, using the fundamental frequency or the third harmonic component depending on the prostate radius. Numerical modelling enabled assessment of the effects of several acoustic parameters on treatment outcomes. The range of treatable prostate radii extended with increasing power, and tended to narrow with decreasing frequency. Reducing the frequency from 8 MHz to 4 MHz or increasing the surface acoustic power from 10 to 20 W/cm(2) led to treatment times shorter by up to 50% under appropriate conditions. A dual frequency configuration of 4/12 MHz with 20 W/cm(2) ultrasound intensity exposure can treat entire prostates up to 40 cm(3) in volume within 30 min. The interdependence between power and frequency may, however, require integrating multi-parametric functions in the controller for future optimisations.

[New ultrasound technologies for the diagnostics of prostate cancer]

CLINICAL/METHODOLOGICAL ISSUE

Prostate cancer is the most common cancer in men. The diagnosis is based on prostate-specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasound (TRUS) guided biopsy. These techniques have considerable limitations, which result in unnecessary biopsies. Furthermore the biopsies are associated with morbidity and costs.

STANDARD RADIOLOGICAL METHODS

Standard gray-scale ultrasound has a low sensitivity and specificity for prostate cancer detection.

METHODOLOGICAL INNOVATIONS

New ultrasound technologies, including color- and power Doppler ultrasound, contrast enhanced US and real-time sonoelastography have shown to improve prostate cancer diagnosis.

PERFORMANCE

Contrast-enhanced ultrasound has shown a sensitivity of 100% (95% CI, 95%), a negative predictive value (NPV) of 99.8% and a positive predictive value (PPV) of 88.8% for prostate cancer detection. Real-time sonoelastography has shown a sensitivity of 86%, a specificity of 81% and NPV of 91% for prostate cancer diagnosis.

ACHIEVEMENTS

Most studies show that these new ultrasound modalities demonstrate a 1.5 to 2.5 times higher detection of prostate cancer per biopsy specimen compared with systematic biopsy. Multicenter studies results are at present lacking but are, however ongoing.

PRACTICAL RECOMMENDATIONS

In patients with suspected prostate cancer (elevated PSA, suspicious DRE) these new ultrasound techniques should be used. These techniques can detect prostate cancer and allow a targeted biopsy approach.

Targeted antimicrobial prophylaxis using rectal swab cultures in men undergoing transrectal ultrasound guided prostate biopsy is associated with reduced incidence of postoperative infectious complications and cost of care

PURPOSE

We evaluated targeted antimicrobial prophylaxis in men undergoing transrectal ultrasound guided prostate biopsy based on rectal swab culture results.

MATERIALS AND METHODS

From July 2010 to March 2011 we studied differences in infectious complications in men who received targeted vs standard empirical ciprofloxacin prophylaxis before transrectal ultrasound guided prostate biopsy. Targeted prophylaxis used rectal swab cultures plated on selective media containing ciprofloxacin to identify fluoroquinolone resistant bacteria. Patients with fluoroquinolone susceptible organisms received ciprofloxacin while those with fluoroquinolone resistant organisms received directed antimicrobial prophylaxis. We identified men with infectious complications within 30 days after transrectal ultrasound guided prostate biopsy using the electronic medical record.

RESULTS

A total of 457 men underwent transrectal ultrasound guided prostate biopsy, and of these men 112 (24.5%) had rectal swab obtained while 345 (75.5%) did not. Among those who received targeted prophylaxis 22 (19.6%) men had fluoroquinolone resistant organisms. There were no infectious complications in the 112 men who received targeted antimicrobial prophylaxis, while there were 9 cases (including 1 of sepsis) among the 345 on empirical therapy (p=0.12). Fluoroquinolone resistant organisms caused 7 of these infections. The total cost of managing infectious complications in patients in the empirical group was $13,219. The calculated cost of targeted vs empirical prophylaxis per 100 men undergoing transrectal ultrasound guided prostate biopsy was $1,346 vs $5,598, respectively. Cost-effectiveness analysis revealed that targeted prophylaxis yielded a cost savings of $4,499 per post-transrectal ultrasound guided prostate biopsy infectious complication averted. Per estimation, 38 men would need to undergo rectal swab before transrectal ultrasound guided prostate biopsy to prevent 1 infectious complication.

CONCLUSIONS

Targeted antimicrobial prophylaxis was associated with a notable decrease in the incidence of infectious complications after transrectal ultrasound guided prostate biopsy caused by fluoroquinolone resistant organisms as well as a decrease in the overall cost of care.

Contemporary pathologic characteristics and oncologic outcomes of prostate cancers missed by 6- and 12-core biopsy and diagnosed with a 21-core biopsy protocol

PURPOSE

To assess the pathological and the oncologic outcomes of the prostate cancer (PCa) missed by 6- and 12-core biopsy protocols by using a reference 21-core scheme.

MATERIALS AND METHODS

Between 2001 and 2009, all patients who had PCa detected in an initial 21-core TRUS biopsy scheme and were treated by a radical prostatectomy (RP) were included. Patients were sorted in 3 groups according to the diagnosis site: sextant (6 first cores; group 1), peripheral zone (12 first cores; group 2) or midline/transitional zone (after 21 cores; group 3). Demographics, pathological features in biopsy and RP specimens and follow-up after RP were analyzed. The 5-year progression-free survival (PFS) was studied in the 3 groups.

RESULTS

During the study period, 443 patients were included. Among them, 67, 23.7 and 9.2% were, respectively, diagnosed in groups 1, 2 and 3. Among PCa diagnosed in midline/transition zone cores, 42% were intermediate or high risk. Unfavorable disease was more frequently reported in group 1 in terms of extraprostatic extension (P = 0.001), high Gleason score (P = 0.001) and progression (P = 0.001). No significant difference was observed between groups 2 and 3 in terms of pathological features in RP specimens and oncologic outcome. The 5-year PFS was 89.7% and not significantly different in patients diagnosed with a 12-core scheme compared to those diagnosed only with 21-core scheme (P = 0.332).

CONCLUSIONS

Our findings emphasize that PCa diagnosed only in a 21-core protocol is at least as aggressive as PCa detected in a 12-core scheme. This study invalidates the widespread idea sustaining that cancers diagnosed by more than 12 biopsies are less aggressive.

Prostate cancer diagnosis in a resource-poor setting: the changing role of digital rectal examination

We undertook this study in order to determine the current role of digital rectal examination (DRE) in the diagnosis of prostate cancer in a resource-poor setting. The diagnosis of prostate cancer has been revolutionized by the introduction of prostate-specific antigen (PSA), transrectal ultrasound (TRUS) for biopsy guidance and more efficient biopsy equipment, but they are not readily available in most developing countries. This is a prospective study of 131 patients with suspected prostate cancer based on clinical presentation, DRE and elevated PSA. The presence or absence of cancer was confirmed by biopsy and histologic examination. Patients with screen- or incidentally-detected prostate cancer were excluded. The most common symptom was the development of lower urinary tract symptoms (LUTS). All patients had abnormal DRE and indurated prostate was the most frequent finding (50%). The mean PSA was 33.9ng/mL: of the 131 patients, 80 (61.1%) had a malignant histology following biopsy, 47 (35.9%) were benign and four (3.0%) were prostate intraepithelial neoplasia (PIN). The low specificity of DRE in the diagnosis of prostate cancer requires that it should be combined with other diagnostic modalities such as PSA and TRUS-guided prostate biopsy. Thus government and health-care providers in resource-poor countries must strive to make these facilities available in order to improve prostate cancer diagnosis.

Optimizing prostate cancer detection during biopsy by standardizing the amount of tissue examined per core

OBJECTIVE

To investigate the effect on cancer detection by varying the number of cores taken for prostate biopsy according to the size of the prostate.

PATIENTS AND METHODS

A retrospective review of a prospectively registered prostate biopsy database identified 3040 consecutive patients undergoing prostate biopsy at a Veterans Administration Hospital between 1994 and 2008. Of 2224 biopsies, 681 (31%) were found to have cancer and 1540 (69%) had negative biopsies. Prostate volume to biopsy core ratios (volume/number of cores) were derived and a comparative analysis was performed to determine the impact on cancer detection rates.

RESULTS

The median prostate volume was significantly smaller for those patients diagnosed with prostate cancer than for those with negative biopsies (33 vs 43 cc, P= 0.01). The median number of cores was the same for both groups of patients (median 12, P= 0.66). The median transrectal ultrasonography TRUS size/core ratio was 3.5 [interquartile range (IQR) 2.5] for patients with identified cancer as compared with 4.7 (IQR = 3.9) for those with negative biopsies (P= 0.000). On multivariable logistic regression analysis TRUS size/core ratio had a significant impact on cancer detection with a relative risk ratio of 1.29 (95% confidence interval, 1.1-1.5, P= 0.001) even when controlled for age, race, prostate volume, digital rectal examination and prostate-specific antigen level.

CONCLUSIONS

Prostate cancer detection can be enhanced by individualizing the number of cores performed to a real-time prostate volume sampling. The present study emphasizes that optimal cancer detection rates were observed when a ratio of 3.5 cc per tissue core was achieved. Proper prospectively designed studies must be performed to further validate these findings.

Antibiotic prophylaxis for transrectal prostate biopsy

BACKGROUND

Transrectal prostate biopsy (TRPB) is a well established procedure used to obtain tissue for the histological diagnosis of carcinoma of the prostate. Despite the fact that TRPB is generally considered a safe procedure, it may be accompanied by traumatic and infective complications, including asymptomatic bacteriuria (bacteria in the urine), urinary tract infection (UTI), transitory bacteremia (bacteria in the blood), fever episodes, and sepsis (pathogenic microorganisms or their toxins in the blood). Although infective complications after TRPB are well known, there is uncertainty about the necessity and effectiveness of routine prophylactic antibiotics and their adverse effects, as well as a clear lack of standardization.

OBJECTIVES

To evaluate the effectiveness and adverse effects of prophylactic antibiotic treatment in TRPB.

SEARCH STRATEGY

The search covered the principal electronic databases: MEDLINE, EMBASE, LILACS and the Cochrane Central Register of Controlled Trials (CENTRAL). Experts were consulted and references from the relevant articles were scanned.

SELECTION CRITERIA

All randomized, controlled trials (RCTs) of men who underwent TRPB and received prophylactic antibiotics or placebo/no treatment, were selected, and all RCTs looking at one type of antibiotic versus another, including comparable dosages, routes of administration, frequency of administration, and duration of antibiotic treatment.

DATA COLLECTION AND ANALYSIS

Two reviewers (ELZ, OACC) independently selected included trials and extracted study data. Any disagreements were resolved by a third party (NRNJ).

MAIN RESULTS

Overall, more than 3500 references were considered and 19 original reports with a total of 3599 patients were included.There were 9 trials analysing antibiotics versus placebo/no treatment, with all outcomes significantly favouring antibiotic use (P < 0.05) (I(2) = 0%), including bacteriuria (risk ratio (RR) 0.25 (95% confidence interval (CI) 0.15 to 0.42), bacteremia (RR 0.67, 95% CI 0.49 to 0.92), fever (RR 0.39, 95% CI 0.23 to 0.64), urinary tract infection (RR 0.37, 95% CI 0.22 to 0.62), and hospitalization (RR 0.13, 95% CI 0.03 to 0.55). Several classes of antibiotics were effective prophylactically for TRPB, while the quinolones, with the highest number of studies (5) and patients (1188), were the best analysed. For 'antibiotics versus enema', we analysed four studies with a limited number of patients. The differences between groups for all outcomes were not significant. For 'antibiotic versus antibiotic + enema', only the risk of bacteremia (RR 0.25, 95% CI 0.08 to 0.75) was diminished in the 'antibiotic + enema group'. Seven trials reported the effects of short-course (1 day) versus long-course (3 days) antibiotics. Long course was significantly better than short-course treatment only for bacteriuria (RR 2.09, 95% CI 1.17 to 3.73). For 'single versus multiple dose', there was significantly greater risk of bacteriuria for single-dose treatment (RR 1.98, 95% CI 1.18 to 3.33). Comparing oral versus systemic administration - intramuscular injection (IM), or intravenous (IV) - of antibiotics, there were no significant differences in the groups for bacteriuria, fever, UTI and hospitalization.

AUTHORS' CONCLUSIONS

Antibiotic prophylaxis is effective in preventing infectious complications following TRPB. There is no definitive data to confirm that antibiotics for long-course (3 days) are superior to short-course treatments (1 day), or that multiple-dose treatment is superior to single-dose.

Prevalence and significance of fluoroquinolone resistant Escherichia coli in patients undergoing transrectal ultrasound guided prostate needle biopsy

PURPOSE

We estimated the prevalence of fluoroquinolone resistant Escherichia coli in patients undergoing repeat transrectal ultrasound guided prostate needle biopsy and identified high risk groups.

MATERIALS AND METHODS

From January 2009 to March 2010 rectal swabs of 136 men from 3 institutions undergoing transrectal ultrasound guided prostate needle biopsy were obtained. There were 33 men with no previous biopsy who served as the controls. Participants completed questionnaires and rectal swab culture was obtained just before performing the prostate biopsy. Selective media was used to specifically isolate fluoroquinolone resistant E. coli and sensitivities were obtained. The patients were contacted via telephone 7 days after the procedure for a followup questionnaire.

RESULTS

A total of 30 patients had cultures positive for fluoroquinolone resistant bacteria for an overall rate of 22% (95% CI 15, 29). Patients with diabetes and Asian ethnicity had higher risks of resistant rectal flora colonization (OR 2.3 and 2.8, respectively). However, differences did not reach statistical significance (p = 0.09 and p = 0.08, respectively). Patients with no prior biopsy had a positive rate of 15% (5 of 33) compared to 24% (25 of 103) in those with 1 or more prior biopsies (OR 1.8, p = 0.27). Five patients (3.6%) had post-biopsy fever while only 1 of those patients had a positive rectal swab.

CONCLUSIONS

Using selective media to isolate fluoroquinolone resistant E. coli from the rectum before transrectal ultrasound guided prostate biopsy, we isolated organisms in 22% of patients with a wide resistance pattern. This protocol may be used to provide information regarding targeted antibiotic prophylaxis before transrectal prostate biopsies.

Detection of fluoroquinolone-resistant organisms from rectal swabs by use of selective media prior to a transrectal prostate biopsy

Sepsis caused by fluoroquinolone-resistant Escherichia coli is a risk for patients undergoing an ultrasound-guided, transrectal prostate biopsy. A method incorporating selective broth and media was evaluated using rectal swabs obtained from 136 patients prior to a biopsy procedure. Fluoroquinolone-resistant organisms were isolated from 22% of the patients included in this study.

Enhanced transrectal ultrasound modalities in the diagnosis of prostate cancer

Standard grayscale transrectal ultrasound has a poor sensitivity for detection of prostate cancer. Saturation biopsy schemes have improved prostate cancer detection rates over standard template biopsy schemes, but carry additional morbidity and cost. Enhanced ultrasound modalities (EUM), including color and power Doppler, contrast-enhancement, harmonic and flash replenishment imaging, and elastography have demonstrated improved prostate cancer detection. EUM targeting areas with increased or abnormal vascularity or firmness for biopsy offer improved prostate cancer detection. EUM, detect prostate cancer more efficiently than standard ultrasound guided biopsies. These emerging technologies may potentially augment standard prostate biopsy in clinical practice.

Intermediate versus low or high prostate-specific antigen density level: comparison of cancer detection rate between 12- and 18-core prostate biopsy

OBJECTIVE

To compare the diagnostic values of 12- and 18-core biopsies with respect to prostate-specific antigen (PSA) levels, prostate volumes (PV) and prostate-specific antigen density (PSAD).

MATERIAL AND METHODS

Transrectal ultrasound-guided prostate biopsies were performed on 233 patients at a single tertiary academic center. Patients were prospectively randomized to the two protocols (12 or 18 core). The cancer detection rates achieved using these two methods were analyzed at different PSA levels, PVs and PSADs.

RESULTS

Considering PSA level and PV simultaneously, patients were stratified into four groups (group A: PSA < 7 ng/ml and PV ≥ 45 cm(3); group B: PSA < 7 ng/ml and PV < 45 cm(3); group C: PSA ≥ 7 ng/ml and PV ≥ 45 cm(3); group D: PSA ≥ 7 ng/ml and PV < 45 cm(3)). 18-core biopsy had a higher cancer detection rate than 12-core biopsy only in group C (55.2% vs 24.1%, p = 0.015). The 233 patients were also stratified into three groups according to PSAD level: the low PSAD group (PSAD < 0.15 ng/ml/cm(3)), the intermediate PSAD group (0.15 ng/ml/cm(3) ≤ PSAD < 0.25 ng/ml/cm(3)) and the high PSAD group (PSAD ≥ 0.25 ng/ml/cm(3)). In the intermediate PSAD group, 18-core biopsy had a higher cancer detection rate than 12-core biopsy (54.2% vs 28.9%, p = 0.048).

CONCLUSION

An 18-core biopsy is more useful than a 12-core biopsy for detecting prostate cancer in patients with high PSA and large PV, that is, with intermediate PSAD level.

Shear wave dispersion ultrasonic vibrometry for measuring prostate shear stiffness and viscosity: an in vitro pilot study

This paper reports shear stiffness and viscosity "virtual biopsy" measurements of the three excised noncancerous human prostates using a new tool known as shear wave dispersion ultrasound vibrometry (SDUV) in vitro. Improved methods for prostate guided-biopsy are required to effectively guide needle biopsy to the suspected site. In addition, tissue stiffness measurement helps in identifying a suspected site to perform biopsy because stiffness has been shown to correlate with pathologies, such as cancerous tissue. More importantly, early detection of prostate cancer may guide minimally invasive therapy and eliminate insidious procedures. In this paper, "virtual biopsies" were taken in multiple locations in three excised prostates; SDUV shear elasticity and viscosity measurements were performed at the selected "suspicious" locations within the prostates. SDUV measurements of prostate elasticity and viscosity are generally in agreement with preliminary values previously reported in the literature. It is, however, important to emphasize here that the obtained viscoelastic parameters values are local, and not a mean value for the whole prostate.

Increasing hospital admission rates for urological complications after transrectal ultrasound guided prostate biopsy

PURPOSE

Transrectal ultrasound guided prostate biopsy is widely used to confirm the diagnosis of prostate cancer. The technique has been associated with significant morbidity in a small proportion of patients.

MATERIALS AND METHODS

We conducted a population based study of 75,190 men who underwent a transrectal ultrasound guided biopsy in Ontario, Canada, between 1996 and 2005. We used hospital and cancer registry administrative databases to estimate the rates of hospital admission and mortality due to urological complications associated with the procedure.

RESULTS

Of the 75,190 men who underwent transrectal ultrasound biopsy 33,508 (44.6%) were diagnosed with prostate cancer and 41,682 (55.4%) did not have prostate cancer. The hospital admission rate for urological complications within 30 days of the procedure for men without cancer was 1.9% (781/41,482). The 30-day hospital admission rate increased from 1.0% in 1996 to 4.1% in 2005 (p for trend <0.0001). The majority of hospital admissions (72%) were for infection related reasons. The probability of being admitted to hospital within 30 days of having the procedure increased 4-fold between 1996 and 2005 (OR 3.7, 95% CI 2.0-7.0, p <0.0001). The overall 30-day mortality rate was 0.09% but did not change during the study period.

CONCLUSIONS

The hospital admission rates for complications following transrectal ultrasound guided prostate biopsy have increased dramatically during the last 10 years primarily due to an increasing rate of infection related complications.

Multicenter evaluation of an investigational prostate cancer methylation assay

PURPOSE

Prostate specific antigen tests have low specificity, which frequently results in unnecessary biopsy and typically limits screening to patients with prostate specific antigen greater than 4.0 ng/ml. We evaluated an investigational prostate cancer methylation specific polymerase chain reaction assay that detects aberrant methylation in 3 markers (GSTP1, RARbeta2 and APC) that indicate the presence of prostate cancer.

MATERIALS AND METHODS

The assay was evaluated in 337 post-digital rectal examination urine samples (178 cancer and 159 noncancer) collected prospectively at a total of 9 clinical sites. Samples were processed wholly or after division into equal portions. Subject prostate specific antigen was 2.0 to 10.0 ng/ml. All subjects underwent transrectal ultrasound guided needle biopsy with 6 or greater cores sampled. Detection of 1 or greater markers indicated positivity.

RESULTS

Methylation specific polymerase chain reaction assay performance was better in whole than in divided urine cohorts (p = 0.035). Assay AUC was 0.72 in the whole urine cohort and 0.67 in the combined population. These values were higher than those of prostate specific antigen alone using 4.0 ng/ml as the cutoff (p = 0.00 and 0.01, respectively). Moreover, the assay together with the Prostate Cancer Prevention Trial risk calculator or a standard nomogram significantly improved AUC in the whole urine cohort and the combined population vs predictive algorithms alone (p <0.05). Assay positive predictive value was 54% in whole urine cohort with prostate specific antigen 2.0 to 4.0 ng/ml and negative predictive value was 87% with prostate specific antigen 4.1 to 10.0 ng/ml. Assay positive predictive value was higher in subjects with all 3 methylation markers positive.

CONCLUSIONS

These data demonstrate that this investigational assay used in conjunction with current screening algorithms may potentially add value to the biopsy decision making process.

COMPLICATIONS FOLLOWING COMBINED TRANSRECTAL ULTRASOUND-GUIDED PROSTATE NEEDLE BIOPSIES AND TRANSURETHRAL RESECTION OF THE PROSTATE

In order to evaluate safety and morbidity aspects of additional systematic prostate biopsies, we have conducted a retrospective review of patients who had undergone transurethral resection of the prostate (TUR-P) combined with additional systemic prostate needle biopsies at the Chang Gung Memorial Hospital. To this end, the records of 80 men presenting consecutively at our institution between February 2001 and January 2004 inclusively were examined. These 80 individuals included patients experiencing obstructive voiding symptoms and those featuring suspicious screening parameters, all of whom were to undergo transurethral resection of the prostate for symptomatic benign prostatic hyperplasia (BPH), all procedures being performed by a single surgeon. A total of 20 (25%) specimens were found to be positive for prostate cancer. Cancer was detected in the transrectal prostate biopsy specimen of 16 of 57 men (28%) who had not undergone a previous prostate biopsy, and for four of 23 (17%) who had undergone at least one previous (benign) biopsy. Mild complications associated with transurethral prostrate resection, such as hematuria and hemospermia, were reported frequently, featuring rates of 10% and 2.5%, respectively; more severe complications being noted far less frequently. Fever, usually of a low grade, was observed post-operatively for six (7.5%) patients, but a prompt return to normal temperature following antibiotic treatment for one day was revealed. Four (5%) patients remained admitted to the hospital for a prolonged period following surgery. A review of the literature concerning transrectal biopsies and TUR-P has shown that surgery-associated complication rates are slightly lower than was the case for our study. Additional systematic prostate biopsies for patients undergoing TUR-P would appear to be a relatively safe treatment procedure. Identification of risk factors for post-surgery complications might further improve the safety of the screening procedure.

Diagnosis of prostate cancer: repeated transrectal prostate biopsy or transurethral resection

BACKGROUND

Transrectal ultrasound-guided biopsy of the prostate is the major method by which prostate cancer is diagnosed. However, many patients might be overlooked with the initial biopsy. Not uncommonly, patients need repeated biopsies when they continue to exhibit suspicious clinical signs. This may cause psychological stress to both patients and doctors. The purpose of this study was to determine how many repeat transrectal biopsies are adequate for prostate cancer detection and when to switch to transurethral resection.

METHODS

We retrospectively studied a cohort of 2,996 patients who had undergone prostate biopsy. If the biopsy specimen was negative for malignancy, patients were given the choice of either being managed with observation or undergoing transurethral resection of the prostate (TURP) if indicated. If there was a high suspicion of cancer, patients were advised to undergo additional biopsies. The primary endpoint of this study was a diagnosis of cancer.

RESULTS

The cancer detection rate was 22.9% (685 of 2,996 patients) in specimens taken during the first transrectal biopsy, 8.7% in those taken during the second biopsy (32 of 336 patients), and 6.1% in those taken during the third biopsy (6 of 98 patients). The cancer detection rate of TURP after 1 negative biopsy result was 9.3% (35 of 375 patients), and that after 2 negative biopsy results was 17.1% (6 of 35 patients). TURP-derived specimens that were pathologically diagnosed as malignant had lower Gleason grade on average, no matter how many repeat biopsies there were in patients whose previous transrectal biopsy specimens were negative for malignancy (p=0.002 for 2 negative biopsy results and p=0.007 for 3 negative biopsy results).

CONCLUSION

The chance of detecting malignancy beyond a third transrectal biopsy procedure is low. TURP, therefore, might be an alternative procedure for obtaining tissue for pathologic diagnosis, especially in patients with rising prostate-specific antigen levels and comorbid illnesses such as obstructive symptoms.

[Prostate biopsy strategies. A review of the literature]

INTRODUCTION

In 1987 transrectal ultrasound was described like the technique for guiding prostate biopsy. Since that time different options of transrectal ultrasound guided prostate biopsy were described.

MATERIAL AND METHODS

We did a reviewed of the different techniques and cores distribution in the prostate biopsy, also we describes the patient preparation and the most important complications.

RESULTS

The majority of the reviewed showed an increase in the sensibility rates with the extended transrectal ultrasound guided prostate biopsies. These improvements generally are due to the most lateral zones.

CONCLUSION

Until now, due to a great experience and a low complications rate, the transrectal ultrasound guided prostate biopsy strategy should be extended respect the classical sextant biopsy with cores from the most lateral zones of the prostate.

Significance of lateral biopsy specimens during transrectal ultrasound-guided prostate biopsies in Japanese men

OBJECTIVES

Lateral biopsies are thought to have a better cancer detection rate compared with standard sextant biopsies. This study aimed to determine whether lateral peripheral zone biopsies in Japanese men who underwent transrectal ultrasound-guided prostate biopsies provided a significantly higher cancer detection rate than sextant biopsies.

METHODS

Between 1999 and 2004, data were collected from 461 men who underwent prostate biopsy and had enough data regarding the performance of lateral biopsies for statistical analysis. There were two categories in this study: (i) patients who underwent sextant prostate biopsies; and (ii) patients who underwent sextant biopsies plus lateral biopsies.

RESULTS

Prostate cancer was detected in 141 (30.6%) of 461 patients. It was detected in 24 (22.2%) of 108 patients who underwent sextant biopsies and 117 (33.1%) of 353 patients who underwent sextant plus lateral biopsies. Lateral biopsies were not associated with a statistically higher rate of positive biopsy findings; however, we found a significantly higher ratio of patients with positive findings in those with prostate specific antigen (PSA) levels <or=10 ng/mL (10 of 40, 25%) than in those with PSA levels >10 ng/mL (one of 71, 1.4%) among those who had positive cores only in lateral biopsy samples (P < 0.0001).

CONCLUSIONS

Lateral biopsies did not show a significantly higher detection ratio of prostate cancer compared to sextant biopsies. However, lateral biopsies were more effective than sextant biopsies in patients with lower PSA levels. Our findings might be useful for the establishment of biopsy strategies to detect prostate cancer, especially in patients with lower PSA levels.

Trans-rectal ultrasound guided biopsy of the prostate: nationwide diversity in practice and training in the United Kingdom

INTRODUCTION

TRUS-guided needle biopsy of the prostate is the standard technique in the diagnosis of prostate cancer. However the practice is highly variable across the United Kingdom. We survey the standard approaches to TRUS biopsy of prostate, highlighting the nationwide diversity of practice and training.

METHODS

One hundred and eighty questionnaires were sent out to specialist registrars, investigating the number of prostate biopsy cores taken, the use of prophylactic antibiotics, rectal preparation and local analgesia in TRUS biopsy of the prostate. One hundred and fourteen trainees (63%) returned the questionnaires. Twenty-three percent reported sextant biopsy as standard, 36% taking eight-core and 26% taking 10 or more cores. There is no standard regime for antibiotic prophylaxis. Eighteen percent also reported rectal preparation as routine. Thirty-eight percent of the patients receive local anaesthesia prior to the biopsy. Overall, 42% of the TRUS biopsies are carried out by urologists, 29% by radiologists and 21% by both. Six percents have nurse practitioners' involvement. Fifty-six percent of trainees are involve in the TRUS biopsy, 68% do not think they received enough training to carry out the procedure.

CONCLUSIONS

TRUS-guided needle biopsy of the prostate is the standard technique in the diagnosis of prostate cancer. Our survey highlights nationwide diversity in practice in the UK with respect of the number of cores taken, antibiotic prophylaxis and local anaesthesia utilisation. This raised the issue of standardising the practice. More urologists are also actively taking part in this procedure, making the structured training increasingly important.

A prospective randomized trial comparing contrast-enhanced targeted versus systematic ultrasound guided biopsies: impact on prostate cancer detection

BACKGROUND

We performed a prospective randomized trial comparing 5 contrast-enhanced color Doppler (CECD) ultrasound (US) targeted biopsy cores to 10 gray-scale US guided systematic biopsy (SB) cores to determine the impact on the cancer detection rate.

METHODS

We prospectively randomized 100 prostate specific antigen (PSA) screening volunteers with an elevated PSA (> or =1.25 ng/ml and free-to-total PSA < 18%) to undergo contrast-enhanced targeted or SB. Contrast-enhanced targeted biopsies with a limited number of five cores were performed into hypervascular areas of the peripheral zone (PZ) during administration of the US contrast agent SonoVue (Bracco, Italy). A subjective grading of the vascularity from 0 to 3 was used: grade 0, no color signal; 1, low density; 2, medium density; and 3, high density of color signals. Ten SBs were obtained in a standard spatial distribution. Cancer detection rates were compared in the groups.

RESULTS

Cancer was detected in 16/50 subjects (32%) by targeted biopsy, and in 13/50 patients (26%) with SB. The cancer detection rate was significantly better for the targeted approach (P < 0.04, McNemar). The detection rate for targeted biopsy cores (15.6% or 39/250 cores) was significantly better than for SB cores (6.8% or 34/500 cores, P < 0.001, McNemar).

CONCLUSIONS

CECD targeted biopsy detected more cancers than SB with a reduced number of biopsy cores.

The influence of prostate volume on prostate cancer detection using a combined approach of contrast-enhanced ultrasonography-targeted and systematic grey-scale biopsy

OBJECTIVE

To evaluate the influence of prostate volume (PV) on the detection of prostate cancer using a combined approach of contrast-enhanced ultrasonography (CEUS) and grey-scale US-guided systematic biopsy (SB).

PATIENTS AND METHODS

We evaluated 345 patients with prostate cancer and a total prostate-specific antigen (PSA) level of >/= 1.32 ng/mL (1.32-35.3, mean 6.6). Biopsies were taken by two independent examiners; one took five CEUS (Doppler) targeted biopsies of hypervascular regions in the peripheral zone, and subsequently the other took 10 systematic prostate biopsies. We assessed the cancer detection rates for the five different subgroups of prostate volumes, i.e. <20, 20-30, 30-40, 40-50 and > 50 mL.

RESULTS

Each technique, SB and CEUS, detected 73.4% and 77.1% of all detected cancers, respectively, but there were statistically significant differences in detection rate only in small glands. Only 69.0% and 70.4% of all cancers were detected by SB in glands of <20 and 20-30 mL, respectively, whereas 88.1% and 80.8% were detected by CEUS.

CONCLUSION

The prostate cancer detection rate for CEUS was significantly higher in prostates of <30 mL (48.1% of the study population) than for SB. Therefore the combined approach of CEUS and SB allows improved cancer detection in patients with small glands and low total PSA values.

Impact of additional sampling in the TRUS-guided biopsy for the diagnosis of prostate cancer

AIM

To evaluate the diagnostic value of 10+ systematic sampling technique when performing transrectal ultrasound-guided (TRUS) prostate biopsy, compared with the sextant biopsy technique for patients with suspected prostate cancer.

METHODS

286 patients with suspected prostate cancer were included in the study. Patients were eligible for the study if they had serum levels of prostate-specific antigen (PSA) >4 ng/ml or ratio PSA <0.25 and/or an abnormal digital rectal examination (DRE). The population sample was divided in three groups: (1) those with positive PSA, PSA ratio and DRE (70 patients); (2) those with positive PSA and PSA ratio but normal DRE (178 patients), and (3) those with positive PSA and PSA ratio, positive PSA velocity and a negative biopsy in the previous 6-month period (38 patients). In addition to the conventional sextant prostate biopsy cores, four more biopsies were obtained from the lateral peripheral zone (10 core biopsy protocol). Additional cores (total of 12-14) were also randomly selected in case of larger prostates (>60 ml) or from suspicious foci revealed by transrectal ultrasound. All additional biopsy cores were submitted separately to the pathological department.

RESULTS

Cancer was detected in 55.7% (39/70) and 69% (48/70) of the patients (for sextant core and for the extended biopsy protocols, respectively) in the first study group, 11% (20/178) and 23% (41/178) of the patients (for the sextant and the extended biopsy protocols, respectively) in the second study group, and 42% (16/38) and 63% (24/38) of the patients (for the sextant and the extended biopsy protocols, respectively) in the third study group. The addition of the lateral peripheral zone (PZ) of the prostate to the sextant biopsy showed a 23, 105 and 50% increase in the number of cancers diagnosed in the first, second and third study groups, respectively. The improvement of cancer detection rate (sensitivity) was statistically significant for all groups evaluated.

CONCLUSION

The 10+ systematic TRUS-guided prostate biopsy improves the detection rate of prostate cancer compared to the sextant biopsy technique alone, especially when performed in men with positive PSA, PSA ratio, and negative DRE.

Penile metastasis from a T1b prostate carcinoma

BACKGROUND

Penile metastasis from incidental prostate carcinoma has not been described to date.

CASE REPORT

The case of a 72-year-old man affected by penile metastasis from incidental prostate carcinoma is described. In March 1998, the patient underwent prostate surgery for lower urinary tract symptoms related to benign prostatic obstruction. Histological examination revealed an incidental adenocarcinoma of the prostate. The pre-operative prostate-specific antigen (PSA) value was 3.6 ng/ml. A prostate biopsy in the peripheral prostate lobes was negative. PSA progressively rose to 8 ng/ml. The prostate biopsy was repeated and was still negative. The patient was subjected to radiotherapy, as a result of which his PSA fell to 0.7 ng/ml. 4 years after prostatectomy, the PSA rose again and the patient underwent hormonal therapy. The PSA fell to < 0.001 ng/ml. In May 2004, the patient reported a painful, erythematous nodule on his penis glans. Surgical biopsy showed a metastasis from prostate adenocarcinoma and he underwent partial penectomy. Due to disease progression, the patient underwent medical therapy. PSA and testosterone were always at minimum levels. 20 months later the patient died.

CONCLUSION

We underline the uncertainty of the biological behaviour and optimal management of incidentally identified prostate carcinoma. In addition, we highlight that biological and clinical progression could be the consequence of inadequate treatment recommendations.

Extended 21-sample needle biopsy protocol for diagnosis of prostate cancer in 1000 consecutive patients

OBJECTIVE

To prospectively evaluate the diagnostic yield of a 21-sample ultrasound-guided needle biopsy protocol as the initial diagnostic strategy for detection of prostate cancer.

MATERIALS AND METHODS

Between December 2001 and October 2005, 1000 consecutive patients underwent 21-sample needle biopsies under local anesthesia, comprising sextant biopsies, 3 additional posterolateral biopsies in each peripheral zone, 3 biopsies in each transition zone (TZ), and 3 biopsies in the midline peripheral zone. Each prostate core was numbered and analyzed separately. The patients were divided into subgroups according to the result of digital rectal examination (DRE), serum prostate-specific antigen (PSA), and prostate volume. We evaluated the cancer detection rate overall and in each subgroup. We compared the results of our biopsy protocol to those from 6-, 12-, and 18-core biopsy protocols by analyzing only those cores from our protocol that would correspond to these biopsy schemes.

RESULTS

Cancer detection rates using 6 biopsy samples (sextant biopsies only), 12 samples (sextant plus lateral biopsies), 18 samples (sextant, lateral, and TZ biopsies), and 21 samples (sextant, lateral, TZ, plus midline biopsies) were 31.7%, 38.7%, 41.5%, and 42.5%, respectively. The 12-sample procedure improved the cancer detection rate by 22% compared with the 6-sample procedure (p=0.0001). The improvement in the diagnostic yield was most marked in patients with a prostate volume > or =55 ml (36.9%), in patients with normal DRE (26.6%), and in patients with PSA<4 (37.5%). The addition of TZ biopsies to a 12-biopsy scheme increased the diagnostic yield by 7.2% overall (p=0.023). Only 10 of 425 (2.3%) patients were diagnosed on the sole basis of midline biopsies.

CONCLUSIONS

Patients with suspected localized prostate cancer should be offered at least 12 biopsies in the peripheral zone and far lateral peripheral zone (statistically significant). TZ biopsies have to be considered, because these biopsies improve the diagnostic yield. For patients with abnormal DRE and/or PSA> or =20 ng/ml, the 6-biopsy scheme seems sufficient (statistically), but 6 far lateral peripheral zone biopsies as well as the TZ biopsies add little incremental value (not significant). Evidence does not support the use of routine midline peripheral zone needle biopsies in the initial biopsy to enhance the detection of prostate cancer.

Hemospermia following transrectal ultrasound-guided prostate biopsy: a prospective study

Hemospermia is known to be associated with transrectal ultrasound-guided prostate biopsy (TRUS-PB). The true incidence of hemospermia, its duration and implications are not well established. We performed a prospective observational study involving patients undergoing TRUS-PB for suspected prostate cancer at our institution. Sixty-three eligible men were included in the study. Most men (84%) undergoing TRUS-PB, who were able to ejaculate, experienced hemospermia, which was associated with some degree of anxiety. The mean duration of hemospermia was 3.5 (+/-1.7) weeks. The number of ejaculations before the complete resolution of hemospermia was 8 (+/-6.7). None of the clinical and pathological factors was a significant predictor of the duration of hemospermia. Patients should be adequately counseled before TRUS-PB to avoid undue anxiety and alterations in sexual activity.

Rentabilidad diagnóstica de los cilindros de los cuernos laterales en las biopsias prostáticas ampliadas a 10 muestras

OBJECTIVE

To value if the increase in the number of cylinders in the prostate's biopsy raise the diagnostic performance of this test.

MATERIAL AND METHOD

In March 2005 we initiate this prospective study with patients who are subject to a first prostate Biopsy by a PSA between 4 and 10 ng/ml and negative rectal touch. Transrectal, echodirected prostatic biopsies with ten punctures are carried out according to the following programme as follows: 6 Biopsies according to classic sextant technique, to what we add 4 cylinders from the most lateral zones of the prostate (lateral horns). The variables are analyzed: Age, Total PSA, Free PSA/Total PSA, prostatic volume and PSA density.

RESULTS

We value 90 patients consecutively. Prostatic adenocarcinoma was diagnosed to 37 of the 90 patients, which means that the diagnostic rate of the extended Biopsy reached a 41%. Nevertheless, the rate for the classic sextant Biopsy was 32.3%. These differences are statistically significant (Mcnemar test 0.008); besides, this supposes a 27% increase in the diagnostic rentability. The "extra" cylinders in the lateral horns detected 8 tumours which were not detected in the cylinders of the the sextant, and 5 of them presented a Gleason higher or equal to 6.

CONCLUSIONS

In our centre we think that the Biopsy extended to 10 cylinders is an adequate strategy for potential prostatic adenocarcinoma patients who are going to be subject to their first Biopsy. Realizing the clinic relevance of the tumours diagnosed thanks to "extra" cylinders, we do not think that this modality implies an over-diagnosis and consequently an overtreatment of the prostate cancer.

MR-compatible assistance system for punction in a high-field system: device and feasibility of transgluteal biopsies of the prostate gland

We present the first cadavic study results concerning the feasibility of the use of an MR-guided assistance system, Innomotion (Innomedic, Herxheim, Germany), for accurate and consistent placement of percutaneous needles in the prostate gland. The MR-compatible assistance system consists of a C-arch, guiding arm and application module (AMO). T1-weighted fast low angle shot (FLASH) 2-D-GRE sequence (TR/TE=110/4 ms) and T2-weighted turbo spin-echo (TSE)-sequences (TR/TE=3200/97 ms) in transversal orientation were used for the monitoring of the punction of the prostate gland. Planning and control of the intervention is to be made outside the scanner room on a desktop computer that receives DICOM images from the scanner. Servopneumatic drives move the AMO to the insertion point. The physician has to introduce the punction needle manually. The mean deviation of the needle tip to the target in a gel phantom was 0.35 mm. An accurate punction of the prostate gland can easily be performed using this system with a transgluteal access. The T2-weighted images are superior for the evaluation of the prostate anatomy and the needle position during the interventions. In conclusion, our preliminary results indicate that this MR-guided assistance system is suitable for an accurate transgluteal needle placement in the prostate.

Improved prostate cancer detection using systematic 14-core biopsy for large prostate glands with normal digital rectal examination findings

OBJECTIVES

To evaluate in a retrospective study the improvements in prostate cancer detection rates for patients with a prostate gland larger than 30 cm3 using a systematic 14-core biopsy strategy compared with a systematic 8-core biopsy.

METHODS

We retrospectively assessed 273 patients with screened prostate-specific antigen (PSA) levels of 3.0 to 50.0 ng/mL. A total of 204 patients with a prostate volume of 30 cm3 or larger and with normal digital rectal examination findings were enrolled in this study. Of the 204 patients, 110 underwent 8-core biopsy and 94 underwent 14-core biopsy of the prostate. We compared the cancer detection rates of prostate biopsy between the 8 and 14-core groups using total PSA, free/total PSA ratio, PSA density, and PSA density adjusted by transition zone volume. We also analyzed the Gleason grade of the biopsy core and the radical prostatectomy specimens.

RESULTS

Of the 204 patients, 40 (19.5%) were identified as having prostate adenocarcinoma. The cancer detection rate for the 8 and 14-core groups was 14.5% (16 of 110 patients) and 24.5% (23 of 94 patients), respectively. The 14-core biopsy had a statistically significant greater cancer detection rate than did the 8-core group in patients with a prostate volume of 30 to 40 cm3 (36.7% versus 11.8%, respectively, P<0.05) and a PSA density adjusted by transition zone volume of 0.38 ng/mL/cm3 or greater (47.8% versus 20.0%, respectively, P <0.05). The difference in tumor grade between the 8 and 14-core biopsy samples was not statistically significant.

CONCLUSIONS

The 14-core prostate needle biopsy is a recommended method for detecting prostate cancer in a large-volume prostate gland without increasing the risk of complications.

Molecular and cellular approaches to patient management in oncology

Many of the techniques that are employed today by pathologists and oncologists to generate a diagnosis, prognosis or prediction of response have not changed over several decades. However, new molecular and cellular technologies will enable more precise and objective decision-making. This review will detail some of the more recent developments in these areas from Veridex, LLC, academic laboratories and other commercial entities. The discussion of molecular technologies will focus on breast sentinel lymph node biopsy, prostate biopsy, carcinoma of unknown primary, prediction of recurrence in lymph node negative colon and breast cancers and pharmacogenomics. The discussion of cellular technologies will focus on the use of circulating cells to serve in both prognostic and predictive capacities and on the use of molecular methods to interrogate the DNA and RNA isolated from these circulating cells.

The Potential Impact of Prostate Volume in the Planning of Optimal Number of Cores in the Systematic Transperineal Prostate Biopsy

OBJECTIVES

We compared the detection rates of different transperineal prostate biopsy protocols with the aim to optimize the number of cores to sample according to prostate volume.

MATERIAL AND METHODS

From October 2002 to October 2004 we evaluated 480 consecutive patients with PSA between 2.5 and 20 ng/ml undergoing the first set of prostate biopsy. All patients underwent a 14-core TRUS-guided transperineal prostate biopsy, including 12 cores in the peripheral and two in the transitional zone. The detection rate of the 14-core scheme was compared to the one of the other biopsy schemes obtained through the exclusion of pairs of cores. Data were stratified according to the different TRUS estimated prostate volumes.

RESULTS

The detection rate of the standard sextant was 35.2%, while those of the 8-core schemes ranged from 37.1 to 38.8%. The 10-core schemes yielded detection rates of 39.6-40.8% and the protocol with 12 biopsies in the peripheral zone diagnosed prostate cancer in 42.1% of the patients. In patients with <30 cc prostate volume, the detection rate of the 14-core scheme was 43.8% and resulted statistically overlapping to the 8-peripheral cores protocol. In patients with 30.1-50 cc prostate volume a 12-peripheral core biopsy reproduced the results of the 14-core sampling. In prostates larger than 50 cc, an even more extensive procedure was mandatory, considering the low detection rate of the 14-core scheme (24.2%).

CONCLUSION

Transperineal prostate biopsy is a safe procedure with a very low complication rate and high cancer detection rate. Prostate volume is the most relevant variable in the planning of the optimal number of cores in the extensive first biopsy set. A protocol with more than 8 peripheral cores) is recommended only in patients with prostate volume larger than 30 cc.