H. Wijkstra

Focal Therapy in Prostate Cancer—Report from a Consensus Panel

PURPOSEnTo establish a consensus in relation to case selection, conduct of therapy, and outcomes that are associated with focal therapy for men with localized prostate cancer.nnnMATERIAL AND METHODSnUrologic surgeons, radiation oncologists, radiologists, and histopathologists from North America and Europe participated in a consensus workshop on focal therapy for prostate cancer. The consensus process was face to face within a structured meeting, in which pertinent clinical issues were raised, discussed, and agreement sought. Where no agreement was possible, this was acknowledged, and the nature of the disagreement noted.nnnRESULTSnCandidates for focal treatment should have unilateral low- to intermediate-risk disease with clinical stage <or=cT(2a). Prostate size and both tumor volume and tumor topography are important case selection criteria that depend on the ablative technology used. Currently, the best method to ascertain the key characteristics for men who are considering focal therapy is exposure to transperineal template mapping biopsies. MRI of the prostate using novel techniques such as dynamic contrast enhancement and diffusion weighed imaging are increasingly being used to diagnose and stage primary prostate cancer with excellent results. For general use, however, these new techniques require validation in prospective clinical trials. Until such are performed, MRI will, in most centers, continue to be an investigative tool in assessing eligibility of patients for focal therapy.nnnCONCLUSIONSnConsensus was derived for most of the key aspects of case selection, conduct of treatment, and outcome measures for men who are undergoing focal therapy for localized prostate cancer. The level of agreement achieved will pave the way for future collaborative trials.

URINARY BLADDER CONTROL BY ELECTRICAL STIMULATION : REVIEW OF ELECTRICAL STIMULATION TECHNIQUES IN SPINAL CORD INJURY

Evacuation of urine in paraplegics without the need for catheters would be possible when voiding could be induced by eliciting a bladder contraction. A challenging option to obtain detrusor contraction is electrical stimulation of the detrusor muscle or its motor nerves. This article reviews the 4 possible stimulation sites where stimulation would result in a detrusor contraction: the bladder wall, the pelvic nerves, the sacral roots, and the spinal cord. With respect to electrode application, sacral root stimulation is most attractive. However, in general, sacral root stimulation results in simultaneous activation of both the detrusor muscle and the urethral sphincter, leading to little or no voiding. Several methods are available to overcome the stimulation‐induced detrusor‐sphincter dyssynergia and allow urine evacuation. These methods, including poststimulus voiding, fatiguing of the sphincter, blocking pudendal nerve transmission, and selective stimulation techniques that allow selective detrusor activation by sacral root stimulation, are reviewed in this paper.

The Application of Three–Dimensional Contrast–Enhanced Ultrasound to Measure Volume of Affected Tissue after HIFU Treatment for Localized Prostate Cancer

Introduction: Adequate monitoring of volume and location of affected tissue might provide helpful information when performing localized ablative therapy for prostate cancer. We hypothesize that the change in blood flow patterns after therapy in comparison to the blood flow pattern prior to therapy can be used to locate and quantify the amount of affected tissue due to the therapy. We describe the use of three–dimensional contrast–enhanced power Doppler ultrasound (3D–CE–PDU) to determine its additive value to visualize the extent of tissue defects created by high–intensity focused ultrasound (HIFU) in correlation with the histopathology of the prostatectomy specimen.Materials and Methods: Nine patients with biopsy–proven localized prostate cancer, who gave informed consent, were included in the protocol. HIFU treatment was performed 1 week in advance of radical retropubic prostatectomy (RRP) as part of a protocol to study the value of HIFU treatment as local ablative therapy for clinical T1–2N₀M₀ prostate carcinoma. 3D–CE–PDU was performed 1 day prior to unilateral HIFU treatment of the affected lobe on biopsy indication and 1 day before RRP using 2.5 g Levovist® (Schering AG, Germany) microbubble ultrasound contrast agent and a Kretz® Voluson 530D ultrasound scanner (Kretztechnik AG, Austria). Ultrasound data and pathology whole–mount sections were stored digitally to allow off–line processing. Human interpretations of HIFU measurements in three–dimensional ultrasound data were based on gray–scale information (local increase in gray level) in combination with power Doppler mode (absence of blood flow). Histopathological analysis of the whole–mount section revealed a broad band of hemorrhagic necrosis in the HIFU–treated area. Using both the ultrasound data and the pathology sections, the total volume of the prostate and of the HIFU–treated area was measured, and relative volumes were obtained.Results: Visual inspection of the three–dimensional reconstruction of contrast–enhanced Doppler measurements revealed the HIFU–affected prostate tissue by the absence of a blood flow pattern. Paired t tests of the relative HIFU volume indicated that Doppler results (mean 21.7%, SD ±10.8%) differed from the pathology results (mean 32.6%, SD ±16.0%), but a good correlation was found between the relative pathology HIFU volume (Pearson correlation r = 0.94, p<0.0015) and mean 3D–CE–PDU HIFU. Closer inspection of the pathology specimen revealed that the outer ring of the macroscopic hemorrhagic necrosis overestimated the actually dead tissue. On microscopy, the border of dead tissue appeared to be 1–2 mm inside the macroscopically identified red hemorrhagic band. 3D–CE–PDU HIFU volumes indicated by the single observers were not statistically different and correlated very well (Pearson correlation r = 0.98, p<0.001).Conclusion: The results illustrate that 3D–CE–PDU is a promising method to determine the size of the defect of HIFU ablative therapy for prostate carcinoma. The absence of blood flow indicated by three–dimensional power Doppler ultrasound images reflects affected tissue after HIFU treatment, and volume measurements of these areas can quantify the amount of affected tissue.

Analysis of ultrasonographic prostate images for the detection of prostatic carcinoma : the automated urologic diagnostic expert system

This paper describes a study on the automated analysis of ultrasonographic prostate images. With image processing, tissue characterization in the prostate was performed to assess the probability of malignancy. During prostate examinations, images were recorded at the positions where biopsies were taken. The used samples were divided into three groups. Two of them were used for the construction of a classification tree, and the third was used for the evaluation of this classification. A sensitivity of 80.6% and specificity of 77.1% were reached retrospectively. In a prospective way, these results were 80.0% and 88.2%, respectively. The prospective predictive value for cancer detection was 85.7%. The presented prospective value for image analysis was almost twice as high as the values normally found for prostate examination.

A PRACTICAL CLINICAL METHOD FOR CONTOUR DETERMINATION IN ULTRASONOGRAPHIC PROSTATE IMAGES

This paper describes a practical method for automated determination of the contour of the prostate in ultrasonographic images. In this method, we use specific edge detection techniques, based on nonlinear Laplace filtering. Possible edges are located at zero-crossings of the second derivative of the image. The strength of the edge is reflected by the value of the gradient of the image at that location. Combining the information about location and strength, an edge intensity image is constructed from the initial ultrasonographic image. In our method, edge enhancement techniques are performed on the edge intensity image. Edges that actually represent a boundary are selected and linked: interpolation techniques are used to fill the gaps between detected boundary edges. The method for contour determination in ultrasonographic images is used for accurate volume measurements in an everyday clinical environment. Its computer implementation is fast, accurate (mean difference within 6% of exact volume) and easy to use.

The Correlation Between Urodynamic and Cystoscopic Findings in Elderly Men with Voiding Complaints

PURPOSEnWe evaluated the urethrocystoscopic findings and results of urodynamic studies in elderly men with voiding complaints.nnnMATERIALS AND METHODSnA total of 492 consecutive patients with voiding complaints underwent a standardized screening program, including transrectal ultrasonography of the prostate, urodynamic investigations with pressure-flow study analysis and flexible urethrocystoscopy.nnnRESULTSnA significant correlation was found between bladder trabeculation and grade of bladder outlet obstruction. Detrusor instability correlated significantly with grade of trabeculation. Grade of obstruction showed a clear correlation with prostatic occlusion of the urethra and the presence of a middle lobe at cystoscopy.nnnCONCLUSIONSnThe findings at urethrocystoscopy correlate well with those of urodynamic investigations.

Contrast specific imaging in the detection and localization of prostate cancer

Prostate cancer (PCa) is the most common cancer in elderly men and is one of the most important causes of death from cancer in men. The diagnosis of PCa is based on a combination of digital rectal examination, PSA and transrectal ultrasound (TRUS). However, this combination does not reach the accuracy of detection and localization necessary for proper decisions on treatment methods. Therefore, biopsies are performed in all cases for which the suspicion of PCa is raised. Even with biopsies, staging and grading of PCa is far from optimal. More accurate imaging is necessary to improve the biopsy sampling, the goals being to replace systematic biopsies by a targeted approach and to improve staging and grading of PCa. Ultrasound imaging of the prostate remains the first choice of imaging to visualize the prostate, however, gray-scale ultrasound imaging has an accuracy of about 50–60% for the detection of PCa and TRUS used for local staging has an even lower accuracy. The development of PCa is associated with changes in the metabolism of tumor cells, and therefore with changes in the blood perfusion of the involved tissue. This paper focuses on contrast specific imaging techniques to visualize these changes in blood perfusion. Techniques such as color and power Doppler imaging, and contrast enhanced imaging techniques using color and power Doppler, harmonic imaging and intermittent imaging are discussed.

Multiparametric ultrasound in the detection of prostate cancer: a systematic review.

AbstractPurposenTo investigate the advances and clinical results of the different ultrasound modalities and the progress in combining them into multiparametric UltraSound (mpUS).MethodsA systematic literature search on mpUS and the different ultrasound modalities included: greyscale ultrasound, computerized transrectal ultrasound, Doppler and power Doppler techniques, dynamic contrast-enhanced ultrasound and (shear wave) elastography.ResultsnLimited research available on combining ultrasound modalities has presented improvement in diagnostic performance. The data of two studies suggest that even adding a lower performing ultrasound modality to a better performing modality using crude methods can already improve the sensitivity by 13–51xa0%. The different modalities detect different tumours. No study has tried to combine ultrasound modalities employing a system similar to the PIRADS system used for mpMRI or more advanced classifying algorithms.ConclusionAvailable evidence confirms that combining different ultrasound modalities significantly improves diagnostic performance.

Three-dimensional grayscale ultrasound: evaluation of prostate cancer compared with benign prostatic hyperplasia.

OBJECTIVESnTo compare the accuracy of the detection, localization, and staging of prostate cancer using transrectal three-dimensional (3D) grayscale ultrasonography (3D-US) with conventional transrectal two-dimensional grayscale ultrasonography (2D-US).nnnMETHODSnFifty patients with clinical localized prostate cancer scheduled to undergo radical retropubic prostatectomy and 50 patients with clinical benign prostatic hyperplasia underwent transrectal ultrasound investigations (2D and 3D). The prostate images were retrospectively analyzed by two ultrasound experts unaware of the clinical findings. The images of the prostate cancer group were correlated with the whole-mount histologic specimens of the prostate.nnnRESULTSnAll percentages are given for experts 1 and 2. The sensitivity, specificity, and accuracy for the detection of prostate cancer without considering the definitive localization of the tumor for 2D-US was 72% and 76%, 50% and 54%, and 63% and 64%, respectively; for 3D-US, the rates were 82% and 88%, 40% and 42%, and 61% and 65%. The sensitivity, specificity, and accuracy of the combination of 2D-US with 3D-US was 88% and 90%, 36% and 38%, and 62% and 64%, respectively. The sensitivity, specificity, and accuracy for the exact localization of the prostate tumor for 2D-US was 44% and 46%, 50% and 54%, and 47% and 50%, respectively; for 3D-US, they were 52% and 62%, 40% and 42%, and 46% and 52%. The staging of prostate cancer using 3D-US was correct in 49% (expert 1) and in 57% (expert 2) of patients. No difference was observed between 2D-US and 3D-US for accurate staging. Both experts judged the interpretation of 3D-US images as superior to that of 2D-US images.nnnCONCLUSIONSnAlthough 3D-US had statistically significant increased sensitivity in the detection of lesions and decreased specificity compared with 2D-US, 3D-US did not result in significant clinical improvement in the detection and staging of prostate cancer.

Role of voiding and storage symptoms for the quality of life before and after treatment in men with voiding dysfunction

PurposePrevious studies on associations between voiding dysfunction and quality of life (QoL) have largely been limited to baseline data. Therefore, we have explored associations between Qmax and voiding and storage sub-scores of the International Prostate Symptom Score (IPSS) before and after treatment with QoL.MethodsAnalysis of a single-center database of 2,316 men with voiding dysfunction attributed to benign prostatic hyperplasia undergoing various medical and surgical treatment forms.ResultsQmax exhibited little correlation with QoL before or after treatment. IPSS inversely correlated with QoL at baseline and after treatment, and IPSS improvements correlated with those of QoL. The associations applied to both the voiding and storage sub-score of the IPSS, with the latter consistently exhibiting somewhat tighter associations.ConclusionsOur post-treatment data support the idea of a cause–effect relationship between voiding symptoms and QoL irrespective of treatment form. While both voiding and storage symptoms contribute to this relationship, storage symptoms play a somewhat greater role.