Characteristics of normal prostate vascular anatomy as displayed by power Doppler

The European Academy of Andrology (EAA) ultrasound study on healthy, fertile men: Prostate-vesicular transrectal ultrasound reference ranges and associations with clinical, seminal and biochemical characteristics

Background

Transrectal ultrasound (TRUS) parameters are not standardized, especially in men of reproductive age. Hence, the European Academy of Andrology (EAA) promoted a multicenter study to assess the TRUS characteristics of healthy‐fertile men (HFM) to establish normative parameters.

Objectives

To report and discuss the prostate and seminal vesicles (SV) reference ranges and characteristics in HFM and their associations with clinical, seminal, biochemical parameters.

Methods

188 men (35.6 ± 6.0 years) from a cohort of 248 HFM were studied, evaluating, on the same day, clinical, biochemical, seminal, TRUS parameters following Standard Operating Procedures.

Results

TRUS reference ranges and characteristics of the prostate and SV of HFM are reported herein. The mean PV was ∼25 ml. PV lower and upper limits were 15 and 35 ml, defining prostate hypotrophy and enlargement, respectively. PV was positively associated with age, waistline, current smoking (but not with T levels), seminal volume (and negatively with seminal pH), prostate inhomogeneity, macrocalcifications, calcification size and prostate arterial parameters, SV volume before and after ejaculation, deferential and epididymal size. Prostate calcifications and inhomogeneity were frequent, while midline prostatic cysts were rare and small. Ejaculatory duct abnormalities were absent. Periprostatic venous plexus size was positively associated with prostate calcifications, SV volume and arterial peak systolic velocity. Lower and upper limits of SV anterior‐posterior diameter after ejaculation were 6 and 16 mm, defining SV hypotrophy or dilation, respectively. SV total volume before ejaculation and delta SV total volume (DSTV) positively correlated with ejaculate volume, and DSTV correlated positively with sperm progressive motility. SV total volume after ejaculation was associated negatively with SV ejection fraction and positively with distal ampullas size. SV US abnormalities were rare. No association between TRUS and time to pregnancy, number of children or history of miscarriage was observed.

Conclusions

The present findings will help in better understanding male infertility pathophysiology and the meaning of specific TRUS findings.

Transurethral surgical anatomy of the arterial bleeder in the enucleated capsular plane of enlarged prostates during holmium laser enucleation of the prostate

Purpose

To identify the endoscopic vascular anatomy of the prostate during Holmium laser enucleation of the prostate (HoLEP), and analyze the clinical risk factors associated with significant arterial bleeding.

Methods

We identified 107 consecutive patients with benign prostatic hyperplasia who underwent HoLEP between September 2009 and August 2010, performed by a single surgeon (S.J.O.). Two independent reviewers reviewed the surgery video database and completed a prespecified form. The location of bleeding arteries was marked at the level of the bladder neck, proximal prostate, distal prostate, and verumontanum. Arterial bleeding was classified into one of three grades according to bleeding severity (grades 2 and 3 indicate significant bleeding).

Results

The mean prostate volume was 65.1±31.5 mL, and the mean prostate-specific antigen (PSA) level was 3.69±3.58 ng/mL. During the HoLEP procedure, the most common locations of significant bleeders were the 2-5 and 7-10 o'clock positions in the proximal prostate. The average number of bleeding arteries was 12.1±7.9 per procedure, and 1.93±1.20 per 10 mL of prostate volume. Multivariate analysis revealed that prostate volume and serum PSA were significant parameters for estimating the number of bleeding vessels.

Conclusions

During the HoLEP procedure, the most common locations of significant bleeders were the 2-5 and 7-10 o'clock positions in the proximal prostate. Prostate volume was associated with the number of bleeders. A careful approach to the capsular plane of the proximal prostate facilitates early hemostasis during the HoLEP procedure, especially with larger adenomas.

Effect of tadalafil once daily on prostate blood flow and perfusion in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia: a randomized, double-blind, multicenter, placebo-controlled trial

OBJECTIVE

To assess effects of tadalafil vs placebo on prostatic blood flow measured by transrectal ultrasonography in men aged ≥45 years with moderate-to-severe benign prostatic hyperplasia-lower urinary tract symptoms.

METHODS

After screening and washout, patients were randomized to placebo (n = 50) or tadalafil 5 mg (n = 47) once daily for 8 weeks. Transrectal ultrasonography was performed at baseline, 4, and 8 weeks. The primary efficacy measure was the prostate transition zone (TZ) resistive index (RI). Secondary efficacy measures were RI in the peripheral zone and bladder neck, color pixel intensity (CPI), and color pixel density (CPD) in all 3 regions. Outcomes were assessed using mixed-model repeated-measures analyses.

RESULTS

The overall treatment effect (tadalafil vs placebo) for the change from baseline through week 8 in prostate TZ RI was not statistically significant (least squares mean change: placebo, -0.01; tadalafil, 0.00; P = .118), nor was the change from baseline in prostate TZ CPI (P = .564) or CPD (P = .592). Results were similar for all flow measures in prostate peripheral zone and bladder neck. The adverse event profile was consistent with previous studies with no new safety findings.

CONCLUSION

Tadalafil for 8 weeks in men with BPH-LUTS did not result in detectable decreases in arterial RI or increases in CPI or CPD in the prostate or bladder neck. Detection of changes may not be possible because of already low baseline RI, insufficient sensitivity of techniques used, or may have been confounded by methodologic variability across sites. Alternatively, other possible mechanisms not assessed in this study may be more prominently involved.

Doppler spectral waveform parameters at neurovascular bundle vessels in patients with prostate biopsy

INTRODUCTION AND OBJECTIVES

There is a need to improve prescreening determination of prostate cancer to better select patients who need biopsy. Such a strategy properly implemented, will decrease the number of negative biopsies for prostate cancer and in turn better balance the risks and morbidity for patients recommended for biopsy. The aim of study is to investigate Doppler spectral waveform parameters of neurovascular bundle (NVB) vessels and determine differences between benign and malignant pathologies.

PATIENTS AND METHODS

We performed a prospective analysis involving 292 patients who received prostate biopsy for elevated prostate-specific antigen (PSA) values or abnormal digital rectal examination, as well as 174 patients with symptomatic benign prostatic hyperplasia. Doppler spectral waveform (DSW) parameters (peak-systolic velocity [PSV], end-diastolic velocity [EDV], and resistive index [RI]) were measured at bilateral NVB vessels through Doppler transrectal ultrasound at the right lateral decubitus position, compared, and analyzed among patients with benign versus malignant histology for each side.

RESULTS

Overall, both PSV and EDV at malignant sides were significantly higher than those at benign sides, as well as lower RI (all p-values <0.05, unpaired t-test). In subgroup analysis with 93 patients of serum PSA between 10 and 20 ng/mL and 56 patients with one-side malignancy, higher EDV and lower RI were significantly associated with malignancies (all p<0.05). The values of PSV and EDV rather than RI might be influenced by the patients' position and RI by the prostate volume.

CONCLUSIONS

In this study, DSW parameters (mainly EDV and RI) at NVB vessels were significantly associated with prostate cancer, particularly in patients with serum PSA of 10-20 ng/mL. It should be in caution that the patients' position and prostate volume may influence the Doppler signal as demonstrated in the current study. These findings can provide more diagnostic information before prostate biopsy.

Evaluation of the resistive index of prostatic blood flow in benign prostatic hyperplasia

OBJECTIVE

The aim of this work is to study the resistive index (RI) of prostatic blood flow by transrectal power Doppler sonography in benign prostatic hyperplasia (BPH) to determine its correlation with other parameters of BPH.

MATERIALS AND METHODS

Eighty-two male patients aged 52-86 years with lower urinary tract symptoms (LUTS) due to BPH were included in the study. Patients with prostate cancer, neurogenic bladder, or with other pathology (e.g. prostatitis, bladder stone) were excluded from the study. All patients were evaluated by full history including Internatinoal Prostate Symptoms Score (IPSS), general and local examination (DRE), neurologic examination, uroflowmetry, laboratory investigations including urine analysis, routine laboratory tests and serum prostate specific antigen (PSA). Transrectal ultrasonography was used to calculate the total prostatic volume. Transrectal Power Doppler Ultrasound (PUD) was used to identify the capsular and urethral arteries of the prostate and to measures the RI value.

RESULTS

The mean prostate volume was 75.1 ± 44.7 g. The mean RI of the right and left capsular arteries were 0.76 ± 0.06 and 0.76 ± 0.07, respectively. The mean RI of the urethral arteries was 0.76 ± 0.08. There was a high significative correlation between the increase of the RI of the right and left capsular and urethral arteries and the degree of obstruction (P value < 0.001), severity of symptoms (P value < 0.001) and also the prostatic volume (P value < 0.001).

CONCLUSION

Resistive index of the prostatic blood flow can be applied as an easy and non-invasive tool to evaluate the lower urinary tract obstruction due to BPH.

Correlations among cardiovascular risk factors, prostate blood flow, and prostate volume in patients with clinical benign prostatic hyperplasia

OBJECTIVE

To investigate the relationships among the cardiovascular risk factors, prostate blood flow, and prostate volume in patients with clinical benign prostatic hyperplasia (BPH).

METHODS

A total of 130 patients with the clinical diagnosis of BPH were recruited. The presence of 5 cardiovascular risk factors, including obesity, diabetes, hypertension, hyperlipidemia, and a history of cardiovascular events, was recorded. The urologic evaluation included digital rectal examination, serum prostate-specific antigen, International Prostate Symptom Score, and transrectal ultrasonography. Doppler spectrum analysis was performed with the patient in the right lateral decubitus position to measure the blood flow in the prostate capsular arteries, periurethral arteries, and neurovascular bundles. The correlations were analyzed between the resistive indexes of the prostatic branches and the cardiovascular risk factors, as well as the transrectal ultrasound findings.

RESULTS

The resistive indexes of the periurethral arteries and right neurovascular bundles showed positive correlations with the number of cardiovascular risk factors in the patients (r=.228, P=.01 and r=.225, P=.011, respectively). The periurethral artery resistive index also correlated positively with both prostate and transitional zone volumes, with the capsular artery correlating positively only with the latter. No significant correlations were noted between the resistive indexes and the International Prostate Symptom Score.

CONCLUSION

Prostate vascular resistance in patients with BPH has positive correlations with cardiovascular risk factors and prostate size. These findings suggest that prostate hypoxia might play a role in the pathogenesis of BPH.

Tandem-robot assisted laparoscopic radical prostatectomy to improve the neurovascular bundle visualization: a feasibility study

OBJECTIVES

To examine the feasibility of image-guided navigation using transrectal ultrasound (TRUS) to visualize the neurovascular bundle (NVB) during robot-assisted laparoscopic radical prostatectomy (RALP). The preservation of the NVB during radical prostatectomy improves the postoperative recovery of sexual potency. The accompanying blood vessels in the NVB can serve as a macroscopic landmark to localize the microscopic cavernous nerves in the NVB.

METHODS

A novel, robotic transrectal ultrasound probe manipulator (TRUS Robot) and three-dimensional (3-D) reconstruction software were developed and used concurrently with the daVinci surgical robot (Intuitive Surgical, Inc., Sunnyvale, CA) in a tandem-robot assisted laparoscopic radical prostatectomy (T-RALP).

RESULTS

After appropriate approval and informed consent were obtained, 3 subjects underwent T-RALP without associated complications. The TRUS Robot allowed a steady handling and remote manipulation of the TRUS probe during T-RALP. It also tracked the TRUS probe position accurately and allowed 3-D image reconstruction of the prostate and surrounding structures. Image navigation was performed by observing the tips of the daVinci surgical instruments in the live TRUS image. Blood vessels in the NVB were visualized using Doppler ultrasound.

CONCLUSIONS

Intraoperative 3-D image-guided navigation in T-RALP is feasible. The use of TRUS during radical prostatectomy can potentially improve the visualization and preservation of the NVB. Further studies are needed to assess the clinical benefit of T-RALP.

Dutasteride Prior to Contrast-Enhanced Colour Doppler Ultrasound Prostate Biopsy Increases Prostate Cancer Detection

OBJECTIVES

This study assessed the effect of premedication with dutasteride, a dual 5alpha-reductase inhibitor, on prostatic blood flow prior to prostate biopsy and its impact on prostate cancer detection.

METHODS

Thirty-six patients, aged 52-74 yr, with elevated prostate-specific antigen (PSA) levels (>or=1.25 ng/ml and free-to-total ratio of <18%) were treated with dutasteride 14 d prior to prostate biopsy. Contrast-enhanced colour Doppler (CECD) ultrasound was performed before and 7 and 14 d after dutasteride treatment. Contrast-enhanced targeted biopsies (<or=5) were performed into hypervascular areas of the peripheral zone only. Subsequently, a second investigator performed 10 systematic biopsies of the prostate in a standard spatial distribution guided by conventional grey-scale ultrasonography on a Combison 530MT unit.

RESULTS

Dutasteride reduced prostatic blood flow in benign prostatic tissue, whereas in prostate cancer areas blood flow was still observed after a 14-d course of dutasteride intake. A reduction of blood flow was observed even after 7 d. Maximum flow reduction was observed after 14 d. Twelve patients (33%) of our cohort were found to have suspicious blood flow and prostate cancer and six cancers (17%) were detected solely by targeted contrast-enhanced biopsy.

CONCLUSION

Premedication with dutasteride seems promising to improve prostate cancer detection by using CECD ultrasound.

Power Doppler ultrasonography of the feeding arteries of the prostate gland: a novel approach to the diagnosis of prostate cancer?

OBJECTIVE

The purpose of this study was to assess the role of spectral Doppler ultrasonographic parameters of the feeding arteries of the prostate for the detection of prostate cancer.

METHODS

A total of 55 patients referred for prostate biopsy with a mean age of 66.4 years (range, 46-82 years) were included. In each patient, Doppler indices from bilateral capsular and urethral arteries were obtained. The indices were compared with regard to malignant (group A) and benign (group B) subgroups of histopathologic outcomes of transrectal ultrasonographically guided prostate biopsy for each side (n = 19 and n = 91 for groups A and B, respectively) and to assess whether the indices were significantly altered on the side with cancer compared with the contralateral side.

RESULTS

The mean pulsatility index value for the capsular artery of group A (1.49 +/- 0.57) was significantly lower than that of group B (1.71 +/- 0.52; P = .048). The mean resistive index and systolic/diastolic ratio for the capsular artery of group A (0.78 +/- 0.10 and 5.40 +/- 2.74, respectively) were lower than those of group B (0.82 +/- 0.08 and 7.40 +/- 4.91) despite being statistically insignificant (P = .075 and .119, respectively).

CONCLUSIONS

Spectral waveform measurements by power Doppler transrectal ultrasonography may be useful in differentiating prostate cancer from benign hypertrophy. Further research is needed to elucidate the potential of spectral Doppler indices of the capsular and urethral arteries.

Écho-Doppler et cancer de la prostate: option ou nécessité ?

PURPOSE

To evaluate the value of power Doppler sonography (PDS) in patients with a serum PSA level greater than 3.5 ng/ml and note the advantages of PDS in management of biopsy cores and staging in prostate cancer.

MATERIAL AND METHODS

A group of 579 patients with a serum PSA level greater than 3.5 ng/ml underwent sextant biopsies. PDS of the prostate was performed in all patients before biopsy indication. Patients underwent six initial sextant biopsies without Doppler. In 141 patients who retained an elevated serum PSA level, an additional series of six to eight ultrasound-guided biopsies with Doppler were indicated. A total of 299 cancers were diagnosed (126 palpable) after initial biopsies and 85 (13 palpable) after additional biopsies. One hundred seven patients with localized cancer (48 palpable) underwent a radical prostatectomy.

RESULTS

An echographic or vascular anomaly was detected in 335 patients; after biopsies this anomaly corresponded to 260 cancers, 39 of which were not visible (false-negative Doppler results). The negative predictive value was 84% and there was no significant relation between PSA level and negative predictive value. After initial biopsies, if an abnormal Doppler signal was present the risk of having positive additional biopsies was 83%. Abnormal disoriented irregular vessels were present in 69% of patients with a Gleason score of 7 or higher versus 31% in patients with a Gleason score less than 7 (p<0.01). Twenty out of 39 patients with T1c cancer invisible with PDS and not palpable (13% of all cancers) underwent a radical prostatectomy. Eleven of 16 cancers with a Gleason score of 6 or less were found insignificant, but in two cases the lesion was advanced (p<0.01). Of cancers with a tumor vessel crossing the capsule, 71% presented an extraprostatic extension (Se: 37.5%, Spe: 93%, PPV: 71%, NPV: 78%) (p<0.01).

CONCLUSION

In prostatic cancer, PDS allows evaluation of aggressiveness features and can optimize the number of useful biopsy cores.

Vascular resistance in the prostate evaluated by colour Doppler ultrasonography: is benign prostatic hyperplasia a vascular disease?

OBJECTIVE

To evaluate prostatic vascular resistance by measuring the resistive index (RI), and flow velocity using colour Doppler ultrasonography (CDUS), in normal prostates and in patients with benign prostatic hyperplasia (BPH) or prostate cancer, as BPH is considered to be a result of urogenital ageing and studies suggest that hyperplasia in the stromal and glandular compartments might be induced by stromal growth secondary to hypoxia, which in turn results from abnormal blood flow patterns.

PATIENTS, SUBJECTS AND METHODS

Ninety-two men (22 with normal prostates, 45 with BPH and 25 with prostate cancer; mean age 56 years) were prospectively evaluated by CDUS. The RI values for the peripheral, central and transition zones were assessed by one investigator. The diagnosis of BPH and prostate cancer was established from histological findings.

RESULTS

The mean (sd) RI in the transition zone was significantly higher only in patients with BPH, at 0.77 (0.05), vs 0.65 (0.05) in the other two groups. In the peripheral and central zones there was no significant difference in the RI among the three groups. Arterial CDUS flow velocity was increased in the transition zone of patients with BPH, but not in the peripheral and central zones.

CONCLUSIONS

The present results support the hypothesis that an age-related impairment of blood supply to the lower urinary tract might have a role in the development of BPH. Although prostate cancer cannot be excluded by measuring RI, high RI values (>0.75) in the transition zone are indicative of BPH.

Prostate Cancer Imaging—What the Urologic Oncologist Needs to Know

Appropriate imaging for prostate cancer patients depends on the clinical disease state of the patient and the question being asked. For patients who do not have a cancer diagnosis, ultrasound is the standard approach, in combination with a sextant biopsy. In the future, contrast-enhanced ultrasound and MR imaging-directed biopsy may improve biopsy yield and decrease biopsy number. For clinically localized disease, endorectal coil MR imaging and bone scanning may play a role in patients who have risk factors for extracapsular extension, but more data are needed to define the role of MR spectroscopy and lymphtrophic nanoparticle MR imaging. In the rising prostate-specific antigen (PSA) setting after definitive local therapy, endorectal coil MR imaging may help define local recurrence, whereas bone scanning can be useful in the setting of higher PSA or rapid PSA velocity.

Newer Modalities of Ultrasound Imaging and Treatment of the Prostate

Gray-scale ultrasound is widely used for assessing BPH and for obtaining prostate biopsies. However, it has limited value for evaluating cancer in the prostate. To improve ultrasound as an imaging modality of the prostate, many new technologies, such as color and power Doppler, 3-dimensional ultrasound of the prostate, and contrast-enhanced ultrasound have been developed. In addition, treatment modalities using ultrasound for the treatment of BPH have been developed. This review presents the recent developments in ultrasound of the prostate.

New Clinical Imaging Modalities in Prostate Cancer

In all prostate cancer disease states, exciting novel imaging technology is being tested that may affect the future care of our patients. New US, MRI, and nuclear medicine techniques are improving both the ability to stage patients and to follow treatment-related changes. See Table 3 for a summary of these novel imaging techniques. Important issues still need to be resolved, including standardizing patient populations within trials, demonstrating the reproducibility of these techniques between different centers, and understanding how information gained from these techniques should influence patient care. We eagerly await answers to these questions.

A comparison of the diagnostic performance of systematic versus ultrasound-guided biopsies of prostate cancer

Transrectal ultrasound (TRUS) is an important tool for urologists and radiologists in the detection of prostate cancer. Various TRUS-guided biopsy techniques are applied in clinical practice. Frequently, only the detection rates achieved with these methods are compared. Other diagnostic performance parameters, particularly the specificity and negative predictive value, are seldom compared. After extensive assessment of the available literature, this review describes the methods of TRUS-guided biopsy for prostate cancer detection. A distinction was made between systematic biopsies and biopsies that target a perceived (hypoechoic or Doppler-enhancing) lesion on imaging. Subsequently, the diagnostic performance (sensitivity, specificity, positive and negative predictive values, accuracies) was compared between these techniques. Imaging-guided biopsy showed better diagnostic performance than systematic biopsy with higher sensitivity. The combinations of sensitivity and specificity were highest for colour Doppler and contrast-enhanced targeted biopsy. Studies targeting hypoechoic lesions had relatively high sensitivity, but specificity was low. Presently however, with widespread prostate-specific antigen screening, fewer prostate cancers are hypoechoic, and the value of targeting hypoechoic lesions has diminished. Performing colour or contrast-enhanced Doppler biopsy or adding these techniques to systematic biopsies improves diagnostic performance, particularly by increasing sensitivity.

Pilot study of radiofrequency interstitial tumor ablation (RITA) for the treatment of radio-recurrent prostate cancer

BACKGROUND

To prospectively evaluate the feasibility, safety, morbidity, and preliminary efficacy of radiofrequency interstitial tumor ablation (RITA) for the focal treatment of patients with local prostate cancer recurrence.

METHODS

Eleven patients with biopsy-proven, hormone-naïve, clinically localized prostate cancer were enrolled in a prospective phase I/II trial. Eight patients had failed prior radiation therapy and three were not candidates for curative primary therapy (median Gleason score 7 and 6, respectively). Median follow-up was 20 months. All patients were treated with RITA in an office setting, under intravenous sedation and were discharged after the procedure. Radiofrequency energy was applied via needles placed transperineally under transrectal ultrasound guidance.

RESULTS

The placement of 1/4 lesions was aborted in two patients due to increasing rectal temperature. Complications included transient macrohematuria (19%), bladder spasms (9%), and dysuria (9%). Serum PSA levels decreased after RITA >50% in 90% of patients, > 70% in 72% of patients, and > 80% in 46% of patients. The mean PSA doubling time after RITA was slower than that before RITA (37 +/- 22 months vs. 14 +/- 13 months, P = 0.008). At 12 months after RITA, 50% of patients with sufficient follow-up had no residual cancer on repeat systematic 12-core biopsy cores and 67% were cancer-free in biopsy cores sampled from the RITA-treated areas.

CONCLUSIONS

RITA treatment is a minimal invasive, rapid, user-friendly, office-based procedure that is well tolerated. Focal ablation with RITA results in effective local disease control in patients with non-metastatic prostate cancer recurrence. Larger, prospective, multicenter clinical studies are needed to confirm these findings.

Vascular damage induced by type 2 diabetes mellitus as a risk factor for benign prostatic hyperplasia

AIMS/HYPOTHESIS

The aim of this study was to evaluate the relationship between benign prostatic hyperplasia (BPH) and arteriosclerosis shown in a model of type 2 diabetes in a trans-sectional population study using contrast-enhanced colour Doppler ultrasound for exact assessment of prostatic blood flow.

METHODS

Contrast-enhanced transrectal colour Doppler ultrasound was performed using a microbubble-based ultrasound enhancer SonoVue for evaluating prostate vascularity (transitional zone [TZ] and peripheral zone [PZ]) in diabetic BPH patients, non-diabetic BPH patients and healthy subjects. Computer-assisted quantification of colour pixel intensity (CPI) was used to objectively evaluate the prostate vascularity. Resistive index measurements were obtained in the TZ and the PZ. Findings were compared between these three groups.

RESULTS

TZ-CPI was significantly lower in diabetic patients than in non-diabetic BPH men (p=0.001), whereas the CPI of the PZ showed no difference between these two groups (p=0.978). TZ-CPI of patients with diabetic and non-diabetic BPH were significantly lower than in controls (p<0.001), but no difference was found between diabetic and healthy patients in the PZ (p=0.022) and borderline significance was seen when comparing patients of the BPH group with the control patients (p=0.019). Resistive index values of the TZ in diabetic patients showed significantly higher values (p<0.001) than the BPH and control groups.

CONCLUSIONS/INTERPRETATION

The significantly lower CPI and higher resistive index values of the TZ in diabetic patients compared with patients with non-diabetic BPH and healthy subjects indicate considerable vascular damage in the TZ of these patients. Diabetic vascular damage may cause hypoxia and may contribute to the pathogenesis of BPH.

Resistance index in benign prostatic hyperplasia using power doppler imaging and clinical outcomes after transurethral vaporization of the prostate

BACKGROUND

Using power Doppler ultrasonography (PDUS), we investigate the change of resistance index (RI) before and after transurethral vaporization of the prostate (TUVP) in benign prostatic hyperplasia (BPH) patients.

METHODS

In all, 49 patients underwent transrectal PDUS before receiving TUVP, three were excluded because of cancer and three could not be followed up. The remaining 43 were enrolled in the present study. Patients were assessed before and 1, 3 and 6 months after surgery, giving a mean duration of follow-up of 9.1 months. International prostate symptom scores (IPSS), quality of life (QOL) scores, postvoiding residual urine volumes (PVR) and maximum urinary flow rates (Qmax) were evaluated and total prostatic volume (TPV) and RI were measured using PDUS.

RESULTS

Resistance index ranged from 0.64 to 0.91. The postoperative parameters except for RI, such as TPV, PVR, IPSS and QOL scores improved significantly at the follow-up assessment after surgery. The elevated RI decreased significantly 1, 3 and 6 months after the treatment. Resistance index significantly decreased after TUVP and IPSS and other urodymamics parameters improved.

CONCLUSIONS

The present study suggested that RI could evaluate the severity of BPH and the degree of intraprostatic pressure or bladder outlet obstruction.

Power Doppler Ultrasonografy (Pdu) as an Additional Tool to Increase Reliability of Systematic Biopsy of the Prostate

Diagnosis of prostate cancer has until recently relied primarily on eight core TR biopsy.

Tests are being carried out to verify whether PDU can effectively aid such diagnosis thereby reducing the number of biopsies and tissue samplings.

This has also been our attempt.

Two groups of patients were examined for increased PSA with or without a palpable prostatic nodule. The first group was composed by 52 patients between 55 and 83 years of age (av. 69.57) with PSA values between 0.87 and 94.91 ng/mL (r.8.085) of which 29 (55.75%) showed a palpable nodule. All patients underwent prostatic eight core TR ecobiopsy.

The second group was composed by 56 patients between 49 and 84 years of age (av.69.19) with PSA values between 1.14 and 59.7ng/mL (r.8.74) of which 33 (58.97%) showed a palpable nodule. This group of patients underwent a PDU just before TR biopsy in order to assess prostatic blood supply and locate possible alterations. Prostatic volume in both groups was never higher than 50 cc. Of the first group 25 patients (48.08%) were prostate cancer positive. Of the second group 31 patients (55.36%) were positive to a biopsy for prostate cancer. In addition 22 out of the 31 showed a vascular irregularity.

From the evidence above (tests carried out by the same operator with two homogeneous groups of patients-Wilcoxon test-) it is clear that PDU usefully worked in diagnosing a higher number of prostate cancers.

Diagnostic sensitivity and specificity was markedly increased by the association of PDU and TR biopsy.

Can Power Doppler Enhanced Transrectal Ultrasound Guided Biopsy Improve Prostate Cancer Detection on First and Repeat Prostate Biopsy?

OBJECTIVE

To determine the utility of Power Doppler enhanced transrectal ultrasound (PD-TRUS) and its guided prostate biopsies in men with prostate specific antigen (PSA) levels between 2.5 and 10 ng/ml and to evaluate its impact on prostate cancer (PCa) detection in men undergoing first and repeat biopsies.

METHODS

A total of 136 consecutive referred men with serum total PSA (Abbott Laboratories, Abbott Park, IL, USA) levels between 2.5 and 10 ng/ml (mean age 64 +/- 9 years, range 45-82) and a normal digital rectal examination were included. 101 underwent a first biopsy whereas 35 had repeat biopsy. Gray-scale transrectal ultrasound (TRUS), and PD-TRUS (B&K Medical, Denmark) were performed in lithotomy position before and during the biopsy procedure. Vascularity accumulation and perfusion characteristics were recorded and graded as normal or abnormal in the peripheral zone of the prostate. A Vienna-nomogram based biopsy regime was performed in all patients on first biopsy and a special biopsy regime on repeat biopsy plus additional biopsies from abnormal sites on PD-TRUS.

RESULTS

Overall PCa detection rate was 34.7% and 25.7% and abnormal accumulation on PD-TRUS was identified in 42.3% and 48.6% on first and repeat biopsy, respectively. The PCa detection rate, on first and repeat biopsy in patients with and without PD-TRUS accumulation were 67.4% versus 10.3% (p < 0.001) and 47.05% versus 5.6% (p = 0.0049), respectively. PD-TRUS directed biopsies were positive in 5.7% and 11.1% on first and repeat biopsy whereas PCa detection using the routine prostate biopsy regime was 94.3% and 88.9% on first and repeat biopsy. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PD-TRUS signal alone for PCa detection on first biopsy was 82.8%, 78.8%, 87.9% and 89.7%, respectively, and 88.8%, 68.0%, 47.0% and 94.4% on repeat biopsy, respectively. In comparison, the results PD-TRUS guided biopsies were 53.8%, 59.1%, 16.7%, and 89.5%, on first biopsy, respectively, and 20.0%, 13.3%, 23.5%, 11.1% on repeat biopsy, respectively.

CONCLUSION

Negative PD-TRUS signal is able to exclude most of the patients without PCa in the PSA range of 2.5-10 ng/ml. As an additional tool at TRUS biopsy PD-TRUS has a high negative predictive value and may help to reduce the number of unnecessary biopsies.

REAL-TIME TRANSRECTAL ULTRASONOGRAPHY DURING LAPAROSCOPIC RADICAL PROSTATECTOMY

PURPOSE

We describe the technical aspects of real-time transrectal ultrasound (TRUS) monitoring and guidance during laparoscopic radical prostatectomy (LRP). Furthermore, we describe the TRUS visualized anatomy of periprostatic structures during LRP.

MATERIALS AND METHODS

In 25 consecutive patients undergoing transperitoneal LRP, baseline preoperative, real-time intraoperative and immediate postoperative TRUS evaluations were performed. To define periprostatic anatomy precisely TRUS measurements were obtained with specific reference to the neurovascular bundle (NVB), prostate apex, membranous urethra, bladder neck, rectal wall and any cancer nodule. Conventional gray scale, power Doppler, harmonic imaging and 3-dimensional ultrasound functions were used.

RESULTS

Real-time TRUS navigation facilitated 3 technical aspects of LRP. 1) It identified the correct plane between the posterior bladder neck and prostate base, allowing quick laparoscopic identification of the vasa and seminal vesicles. 2) It identified the occasional, difficult to see distal protrusion of the prostate apex posterior to the membranous urethra, thus enhancing apical dissection with negative margins. 3) It provided visualization of any hypoechoic nodule abutting the prostate capsule, alerting the laparoscopic surgeon to perform wide dissection at that location. TRUS measured various anatomical parameters including i) the mean distance +/-SD between the NVB and the lateral edge of the prostate a) at apex (1.9 +/- 0.9 mm), b) base (2.5 +/- 0.8 mm) and c) tip of seminal vesicle (4.0 +/- 1.6 mm), ii) the dimensions of the NVB a) before (4.5 x 3.9 mm), b) after (4.2 x 3.6 mm) nerve sparing LRP and c) after nonnerve sparing LRP (0.9 x 0.9 mm), iii) arterial blood flow resistive index within NVB a) before (0.83 +/- 0.04), b) after (0.84 +/- 0.03) nerve sparing LRP and c) after nonnerve sparing LRP (0), iv) and the length of membranous urethra a) before (12.2 +/- 1.1 mm) and b) after (11.7 +/- 1.0 mm) surgery. Focal distortion of the prostate surface by an exophytic nodule was visualized on TRUS in 3 patients, necessitating ipsilateral nerve resection at LRP and contributing to negative surgical margins.

CONCLUSIONS

This initial experience suggests that real-time intraoperative TRUS guidance may enhance anatomical performance of LRP. This improved understanding of periprostatic anatomy has the potential to improve functional and oncological outcomes. Such corroboration is awaited.

Colour Doppler ultrasonography for detecting perineural invasion (PNI) and the value of PNI in predicting final pathological stage: a prospective study of men with clinically localized prostate cancer

OBJECTIVES

To assess the ability of colour Doppler transrectal ultrasonography (CD-TRUS) to improve the accuracy of detecting perineural invasion (PNI, reported to be an independent predictor of extraprostatic extension) and in predicting the pathological stage of the cancer, comparing it with the results of grey-scale TRUS-guided biopsies.

PATIENTS AND METHODS

This prospective study included 47 men with clinically localized disease; all underwent 10-core TRUS-guided biopsy and two bilateral CD-TRUS-guided biopsies, targeted on the area adjacent to the neurovascular bundle. The rates and accuracy of PNI detection on 10-core and CD-TRUS-targeted biopsies were compared with the pathological outcome. Various patient, clinical and pathological factors were compared, and multivariate analysis used to assess the value of the technique in predicting PNI and pathological outcome.

RESULTS

CD-TRUS-guided biopsies predicted the presence of PNI in the radical prostatectomy specimens with a sensitivity of 89%, and specificity and positive predictive values of 100%. Seven of 24 (29%) patients with PNI on the needle biopsies had pT3 disease. Conversely, the absence of PNI on guided biopsy accurately predicted pathologically localized disease in 96% (negative predictive value) of patients. However, the results of multivariate analysis showed that serum prostate-specific antigen was the only strong predictor of pT3.

CONCLUSION

CD-TRUS is a useful tool for detecting PNI and predicting pathological localized cancer; it can be used in candidates for nerve-sparing radical prostatectomy.

Prostate: high-frequency Doppler US imaging for cancer detection

PURPOSE

To evaluate cancer detection with targeted biopsy of the prostate performed on the basis of high-frequency Doppler ultrasonographic (US) imaging findings versus cancer detection with a modified sextant biopsy approach with laterally directed cores.

MATERIALS AND METHODS

Sixty-two patients were prospectively evaluated with gray-scale, color, and power Doppler transrectal US performed with patients in the lithotomy position. Gray-scale and Doppler findings within each sextant were rated on a five-point scale. Up to four targeted biopsy specimens were obtained from each patient on the basis of Doppler findings; this was followed by a modified sextant biopsy. Conditional logistic regression analysis was performed to compare the positive yields for targeted and sextant biopsy specimens. Clustered receiver operating characteristic analysis was performed to compare gray-scale, color, and power Doppler detection of cancer at sextant biopsy sites.

RESULTS

Cancer was detected in 18 (29%) of 62 patients, including 11 patients in whom cancer was detected with both sextant and targeted biopsy, six in whom cancer was detected only with sextant biopsy, and one in whom cancer was detected only with targeted biopsy. The positive biopsy rate for targeted biopsy (24 [13%] of 185 cores) was slightly higher than that for sextant biopsy (36 [9.7%] of 372 cores; P =.1). The odds ratio for cancer detection with targeted versus sextant cores was 1.8 (95% CI: 0.9, 3.7). Receiver operating characteristic analysis demonstrated that overall identification of positive sextant biopsy sites was close to random chance for gray-scale (area under the curve, 0.53), color Doppler (area under the curve, 0.50), and power Doppler (area under the curve, 0.47) imaging.

CONCLUSION

Targeted biopsy performed on the basis of high-frequency color or power Doppler findings will miss a substantial number of cancers detected with sextant biopsy.

Advances in ultrasound for the detection of prostate cancer

The introduction of ultrasound (US) microbubble contrast agents has dramatically expanded the possibilities for US detection of prostate cancer. Recent advances in US technology have increased the value of US contrast agents. Many newer US techniques, which are quite sensitive for detection of microbubbles, are yet to be explored for prostate applications. A critical evaluation of the current status of transrectal US imaging for the detection of prostate cancer and background information for US contrast agents and imaging techniques are presented. Early results have demonstrated the feasibility of US contrast agents to enhance US imaging of prostatic disease. The application of US contrast agents for the detection and clinical staging of prostate cancer is promising. Future clinical trials are needed to determine whether the promise of contrast-enhanced US of the prostate will evolve into widespread clinical application.

High-frequency Doppler US of the prostate: effect of patient position

PURPOSE

To evaluate cancer detection with directed biopsy of the prostate on the basis of high-frequency Doppler ultrasonographic (US) findings, and to determine the effect of patient position on the observed flow pattern.

MATERIALS AND METHODS

Thirty-two patients were evaluated in the left lateral decubitus position with gray-scale, color Doppler, and power Doppler transrectal US. Up to four directed biopsy specimens were obtained on the basis of gray-scale and Doppler US findings, and modified sextant biopsy followed. Analysis of variance and the Wilcoxon signed rank test were used to evaluate the distribution of Doppler signals within the prostate. Three healthy volunteers with no known prostate disease were also examined in supine and both decubitus positions.

RESULTS

In the patient group, both color and power Doppler US demonstrated increased flow on the left side of the prostate, with greater flow toward the base of the gland (P <.002). Consequently, 62 of 90 directed-biopsy cores were obtained in the left base and mid-gland. The positive biopsy rate for directed biopsy was not significantly different from that of sextant biopsy (P =.4). Seven patients had cancer that was identified with sextant biopsy, but only four cancers were identified with directed biopsy. Each of the three healthy volunteers demonstrated increased Doppler flow on the dependent side when the subject was in the lateral decubitus position.

CONCLUSION

The positive yield of directed biopsy was similar to the yield of sextant biopsy. On the basis of observations made in healthy volunteers, the authors conclude that flow asymmetry in patients who underwent biopsy may have been related to patient position.