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R Kranse

Publications and source records attributed to R Kranse.

36 records · Page 2Linked to original sources
PubMed1997

Complications of transrectal ultrasound-guided systematic sextant biopsies of the prostate: evaluation of complication rates and risk factors within a population-based screening program.

OBJECTIVES: Screening for prostate cancer to reduce the mortality and morbidity from this disease has become an important issue in recent years. Of all procedures used to diagnose prostate cancer, biopsy of the prostate is the cause of most complications. To evaluate the safety of the screening procedure, we have studied the complications and risk factors for complications within the screened population of the European Randomized Study of Screening for Prostate Cancer (ERSPC), Rotterdam section. METHODS: Between June 1994 and July 1996, 1687 transrectal ultrasound-guided systematic sextant biopsies were performed after screening 6198 men through prostate-specific antigen level, digital rectal examination, and transrectal ultrasonography. RESULTS: From these 1687 biopsies, 302 cases of prostate cancer were diagnosed. Mild complications such as hematuria and hematospermia were reported frequently with rates of 23.6% and 45.3%, respectively. More severe complications were far less frequently seen. Fever, usually of low grade, was seen after 4.2% of biopsies. Seven men (0.4%) were admitted to a hospital after biopsy. Risk factors for complications could not be identified. CONCLUSIONS: Review of the literature concerning transrectal biopsies of the prostate shows that the complication rates within this screened population are comparable to those reported within referred patients. The admittance rate is slightly lower. Transrectal ultrasound-guided systematic sextant biopsy of the prostate is a safe procedure for the diagnosis of prostate cancer within the general population; however, identification of risk factors for complications might further improve the safety of the screening procedure.

Age Factors↗
PubMed1997

Free and total prostate-specific antigen in a screened population.

OBJECTIVES: To determine whether the ratio of free to total (F/T) prostate-specific antigen (PSA) can differentiate between men with prostate carcinoma or benign conditions in a screened population. SUBJECTS AND METHODS: Total and free serum PSA (measured using Delfia PSA assays, Abbott IMx and Hybritech Tandem E methods) were determined retrospectively in 1726 men aged 55-77 years, in whom 67 prostate carcinomas were detected by screening with a digital rectal examination, transrectal ultrasonography, and total serum PSA level. Predictors for a positive biopsy result were estimated as a function of total PSA, free PSA and the combination of both. RESULTS: There was an excellent correlation between the Delfia ProStatus, the Abbott IMx and the Hybritech Tandem E assays. Compared with the total serum PSA level, the F/T ratio improved the specificity significantly only in those men with a total PSA of > or = 7 ng/mL. Using the information given by the total and free PSA values, a maximum sensitivity of 75% at a specificity of 74% was obtained for the whole PSA range from 4 to 10 ng/mL; the maximum sensitivity was 79% with a specificity of 71%. CONCLUSION: The optimal mathematical combination of free and total serum PSA improves the specificity of total serum PSA level in detecting prostate carcinoma more than the does the F/T PSA ratio.

Aged↗
PubMed1997

Tumour control according to pathological variables in patients treated by radical prostatectomy for clinically localized carcinoma of the prostate.

OBJECTIVE: To evaluate the diagnosis, outcome and final pathology of radical prostatectomy for prostate cancer performed by urologists in a clinic where six urologists perform a total of 50 radical prostatectomies a year, using radical prostatectomy specimens processed routinely. PATIENTS AND METHODS: Radical prostatectomy was performed in 273 patients who were followed prospectively. The radical prostatectomy specimens were evaluated for pathological stage, histological grade, capsular perforation, positive and apical margins of resection, seminal vesicle invasion, perineural invasion and vascular invasion; the lymph node status was also determined. The relationship between these variables and clinical progression, local recurrence, distant metastases, biochemical progression, overall survival and cancer-specific survival was assessed. RESULTS: All evaluated variables were significantly predictive for clinical and biochemical progression in the univariate analyses, and all but perineural invasion and lymph node status for cancer-specific survival. Multivariate analysis showed vascular invasion to be the most important prognostic variable, followed by capsular perforation, positive margins of resection and poorly differentiated carcinoma. The overall results for the evaluated variables were comparable to the results from centres with greater experience. CONCLUSIONS: The outcome of treatment in this small clinic was similar to that from larger clinics with more experience. The routine evaluation of the radical prostatectomy specimens identified pathological variables which were important prognostic factors, with vascular invasion, capsular perforation, positive margins of resection and poorly differentiated carcinoma being the most significant. The extent of vascular invasion should be part of the routine evaluation of radical prostatectomy specimens.

Aged↗
PubMed1997

The free-to-total serum prostate specific antigen ratio for staging prostate carcinoma.

PURPOSE: We analyzed the relationship between the free-to-total PSA ratio and prostate cancer tumor stage and grade compared to total serum PSA. MATERIALS AND METHODS: In 123 patients clinical and pathological grade and stage were related to total serum PSA and free-to-total PSA ratio. RESULTS: Total serum PSA paralleled clinical staging of prostate cancer. The distributions of total serum PSA and the free-to-total PSA ratio were significantly different between benign and malignant diseases (any stage), and between any T category and nodal disease. For serum PSA significant differences were noted between the distributions of men with locally confined (stages T1 and T2) and locally extended (stage T3) disease, and between all T categories and systemic metastatic disease. This finding was not noted for the free-to-total PSA ratio. CONCLUSIONS: The free-to-total PSA ratio has no additional value in clinical staging of prostate carcinoma compared to serum PSA. The free-to-total PSA ratio may be considered the result of cell differentiation and not an indicator of tumor load.

Humans↗
PubMed1997

Analytical evaluation of the new Prostatus PSA Free/Total assay for prostate-specific antigen as part of a screening study for prostate cancer.

In this communication a limited analytical study is described on the new Prostatus PSA Free/Total assay. The study is considered as a side study of the European Randomized Study of Screening for Prostate Cancer. The between-day imprecision with 8 control samples for free prostate-specific antigen ranged from 10.3% at 0.17 microg/l to 3.7% at a concentration of 35.5 microg/l, while for total prostate-specific antigen we found 7.3% at 0.69 microg/l and 4.3% at 70.7 microg/l. For total prostate-specific antigen we found excellent agreement between the new assay and well-established assays like Abbott IMx and Hybritech Tandem-E, both for prostate cancer and benign prostate hyperplasia specimens. The age-specific reference ranges proved to be well-comparable with the literature data both for free and total prostate-specific antigen.

Adult↗
PubMed1997

The free-to-total prostate specific antigen ratio improves the specificity of prostate specific antigen in screening for prostate cancer in the general population.

PURPOSE: The ratio between free and total prostate specific antigen (PSA) in serum improves the specificity of total serum PSA for the detection of prostate carcinoma in select populations. The value of the free-to-total PSA ratio for a PSA of 4.0 to 10.0 ng./ml. was analyzed in a screening population. MATERIALS AND METHODS: From 4,800 participants 55 to 76 years old 977 biopsies were obtained because of an abnormal digital rectal examination, suspicious transrectal ultrasonography and total serum PSA 4.0 ng./ml. or more. Of 191 patients with prostate carcinoma detected 101 had a serum PSA of 4.0 to 10.0 ng./ml. and 54 of them underwent radical prostatectomy. A free-to-total PSA ratio of 0.20, age specific PSA reference ranges and a PSA density of 0.12 ng./ml./cc were evaluated for the ability to increase the specificity of total serum PSA in predicting positive prostate biopsy results. RESULTS: Receiver operating characteristics curves for the free-to-total PSA ratio showed a significant increase in specificity compared to PSA. Retrospective application of age specific PSA reference ranges, the free-to-total PSA ratio and the PSA density decreased the number of biopsies significantly by up to 40% in our study, with a decrease in cancer detection rate of 12%. When used in combination with digital rectal examination, the pathological stage of undetected carcinomas appeared favorable. CONCLUSIONS: The free-to-total PSA ratio may be used to decrease biopsies in patients with an intermediate PSA of 4.0 to 10.0 ng./ml.

Aged↗
PubMed1996

European randomized study of screening for prostate cancer--the Rotterdam pilot studies.

Five randomized pilot studies of screening for prostate cancer (PC) have been conducted in the area of Rotterdam from 1991 to 1994. The purpose of these studies was to establish the feasibility of a randomized screening protocol with PC mortality as the major end point in The Netherlands and at a European level. All procedures related to recruitment of participants, to application of the screening tests and to data collection were evaluated. Men (7,200) aged 55-74 years were invited through the Rotterdam Population Registry. The recruitment rate over the 5 pilot studies averaged 38.2% (2,747 men). Recruitment procedures proved to be relevant for establishing higher participation rates (invitation and consent by mail). The screening tests were well accepted and tolerated. The general population-based character of the sample was confirmed by studying symptoms of prostatic disease in participants and in men who refused participation. Data based on one PSA serum determination, rectal examination and transrectal ultrasonography are presented; 204/1,403 men (14.5%) had a positive screening result by either test combination and underwent biopsy. Forty-nine cancers were found in 1,403 men (3.5%); 65% of prostate cancers (17/26) identified in men who eventually underwent radical prostatectomy proved to be locally confined. From the pilot studies, we conclude that a large contribution to a European Randomized Study of Screening for Prostate Cancer (ERSPC) can be made by recruiting about 40,000 men in the area of Rotterdam. The preliminary data suggest that after confirmation of the present data during the first years in the European study, DRE and TRUS can be withheld depending on the PSA result in a large proportion of the screening population.

Age Factors↗
PubMed1996

Some analytical considerations on the measurement of prostate-specific antigen.

In this study, various analytical aspects of the determination of serum prostate-specific antigen are described as applied to the Abbott IMx PSA and the Hybritech Tandem-E PSA assays. We used mainly specimens from a prostate cancer screening study in progress. A very good comparability between the assays proved to exist in our hands. The long-run variation (16 months) was also rated as acceptable, both for the IMx and the Tandem-E method. The method of choice, Tandem-E, showed good reagent stability over this period. We found, however, a difference in accuracy (Tandem-E +/- 8% higher values) that could not be explained by comparison with Tandem-R.

Humans↗
PubMed1995

Estimation of the lag time between detrusor pressure- and flow rate-signals.

In a urodynamic measurement setup there is a considerable spatial separation between the uroflowmeter and the location where the detrusor pressure is measured. Therefore, a "time shift" (or lag time correction) has to be applied to one of these signals in order to align related samples in studies where pressure and flow rate are considered simultaneously (e.g., assessment of bladder contractility or bladder outlet resistance). Currently, a heuristic value for this time shift of 0.8 s is applied. In this article, we present a method to estimate the lag time directly from the measurements. Using this method we have found, amongst others, that the mean lag time in our clinic is 0.6 s for males, 0.4 s for females voiding in sitting position, and 1.1 s for females voiding in standing position using a special receptacle in video urodynamics. Furthermore, we found that sphincter/urethral activity during voiding (which causes a drop in flow rate and an accompanying increase in detrusor pressure) is associated (on average) with shorter lag times than straining (when a positive pressure rise accompanies an increase in flow rate). Additionally strong evidence is provided that lag time correction is not a major source of error in urodynamics.

Female↗
PubMed1995

The value of screening tests in the detection of prostate cancer. Part I: Results of a retrospective evaluation of 1726 men.

OBJECTIVES: The ratio between free and total prostate-specific antigen (PSA) in serum (F/T ratio) was shown to improve the differentiation between prostate carcinoma and benign conditions in selected series of patients. In this study the F/T ratio was analyzed for its ability to improve the specificity of total serum PSA, digital rectal examination (DRE), and transrectal ultrasonography (TRUS) for the detection of prostate cancer in an unselected screening population of men identified in the Rotterdam population. METHODS: In 1726 men between 55 and 76 years old, 67 prostate carcinomas were detected by DRE, TRUS, and total serum PSA (Abbott IMx, Hybritech Tandem E). The DELFIA ProStatus PSA EQM and ProStatus PSA Free/Total assays (Wallac) were applied in retrospect to determine total and free serum PSA. Age, total prostate and inner zone volumes were taken into consideration. RESULTS: Sixty-seven carcinomas were detected, two by TRUS and three by DRE alone. Total serum PSA was the most important single predictor of prostate cancer, followed by DRE. The F/T ratio increased the specificity of total serum PSA in the PSA range between 4.0 and 10.0 ng/mL. However, this improved specificity was not significant, nor for gland volumes restricted to 50 mL or less. CONCLUSIONS: The combination of total serum PSA and DRE remains the standard for detection of prostate carcinoma in a screening population. Their specificity may be improved minimally by the F/T ratio, but not significantly in a sample of 1726 screened men. The threshold of the F/T ratio, and the optimal PSA range for its application, remains to be assessed prospectively.

Aged↗
PubMed1995

The value of screening tests in the detection of prostate cancer. Part II: Retrospective analysis of free/total prostate-specific analysis ratio, age-specific reference ranges, and PSA density.

OBJECTIVES: The ratio between free and total prostate-specific antigen (PSA) in serum (F/T ratio) was shown to improve the specificity of total serum PSA for the detection of prostate carcinoma in selected populations. In this study, the value of the F/T ratio for screening of prostate cancer was compared with that of age-specific reference ranges for PSA and PSA density (PSAD) by a simulation experiment. METHODS: In 1726 men between 55 and 76 years old, 67 prostate carcinomas were detected by application of digital rectal examination (DRE), transrectal ultrasonography (TRUS), and total serum PSA. A serum PSA of 4.0 ng/mL or more, an abnormal DRE, or an abnormal TRUS were the indications to perform 308 biopsies. A simulation was performed in which an F/T ratio of 0.20 (ProStatus PSA Free/Total), age-specific PSA reference ranges, and a PSAD of 0.12 ng/mL/cc were used to study their capability to increase the specificity of total serum PSA in predicting prostate biopsy results. RESULTS: Using age-specific PSA reference ranges and DRE as indicators for biopsy, a reduction of 37% (113) of biopsies would have been obtained with a loss of detected cancers of 12% (11). For the use of PSAD and DRE, these numbers were 28% (96) and 11% (7), respectively. Application of a serum PSA of 4.0 ng/mL or more and an F/T ratio of 0.20 or less and an abnormal DRE as indicators for biopsy would reduce the number of biopsies by 37% (112) and the number of detected cancers by 11% (7). The biopsy to prostate cancer ratio of these simulations varied between 3.3 and 3.6. Minimal loss of cancer detection of 3% (2) with a reduction in the number of biopsies of 17% (53) is obtained when TRUS is omitted from the screening protocol. Selecting men by a total serum PSA value of 2.0 ng/mL for further diagnostic workup by TRUS and DRE would have reduced the number of biopsies by 30% (102), and the number of cancers detected by 6% (4). CONCLUSIONS: The most cost-effective protocol for screening prostate carcinoma appears to be prescreening by total serum PSA. The F/T ratio might be used to detect carcinomas in the PSA range below 4.0 ng/mL, but the best threshold remains to be assessed.

Age Factors↗
PubMed1995

Reasons for the weak correlation between prostate volume and urethral resistance parameters in patients with prostatism.

In an attempt to increase our understanding of the clinical syndrome of benign prostatic hyperplasia (BPH) an analysis was made of the association between prostate volume as measured by transrectal ultrasound and several reported urodynamically determined urethral resistance parameters. Two types of obstruction can be recognized on the basis of urodynamic data: a compressive type characterized by a high urethral opening pressure and a prolonged isovolumetric contraction phase before urine flow can start, and a constrictive type characterized by a normal opening pressure and an increased slope of the urethral resistance relation. A combination of both types is often seen in BPH. In our study, parameters that selectively quantify compression correlate weakly to moderately with prostate volume, whereas parameters that mainly quantify constriction do not correlate at all with prostate volume. Parameters that combine a measure for compression and constriction correlate less well with prostate volume than parameters that mainly quantify compression. The variation in prostate volume was found to determine the variation in urethral resistance by 15% or less depending on the parameter used, which implies that the different pathophysiological mechanisms that can increase urethral resistance in the complex process of clinical BPH are mainly determined by factors other than the volume of the prostate. Thus, despite the lack of correlation between prostate volume and urethral resistance, pressure-flow studies and the determination of urethral resistance parameters provide a valuable contribution to the understanding of the pathophysiology of voiding dysfunction in men with symptoms of prostatism.

Adult↗
PubMed1995

Dependence of male voiding efficiency on age, bladder contractility and urethral resistance: development of a voiding efficiency nomogram.

The influence of age, urethral resistance and bladder contractility on voiding efficiency was evaluated by pressure-flow studies in 138 men of a mean age of 60 years (range 18 to 86). From these studies the urethral resistance parameter was calculated and the maximum bladder contraction strength was determined. Premature fading of the bladder contraction was quantified by a bladder contraction strength decay factor. Voiding efficiency was expressed by the parameter of post-void residual urine volume as a percentage of the initial bladder volume. Multiple regression analysis showed that voiding efficiency depended significantly in descending order of importance on urethral resistance, maximum bladder contraction strength and bladder contraction strength decay factor. Patient age was not an independent factor. Maximum bladder contraction strength and bladder contraction strength decay factor were not correlated, suggesting that maximum bladder contraction strength and its decay constitute different properties of bladder contractile function. A voiding efficiency nomogram is proposed, making use of the values for maximum bladder contraction strength and urethral resistance in individual patients. Such a nomogram may have predictive value for the occurrence of acute retention but it must be tested prospectively.

Adolescent↗
PubMed1993

A critical comparison of methods proposed for quantification of bladder outlet obstruction.

Performance studies of parameters for bladder outlet obstruction in BPH patients before and after a TURP in terms of sensitivity and specificity can easily be criticized because in roughly 25% of the patients it is not clear if the clinical symptoms are related to increased outlet obstruction or impaired bladder contractility. This abstract presents objective alternatives.

Humans↗
PubMed1990

Computer-controlled wheelchair ergometer.

A new wheelchair ergometer has been designed in which a combination of realistic simulation of wheelchair propulsion--with adjustable parameters for rolling resistance, air drag, wind speed and slope--and force measurement has been realised. The static solution enables the measurement of physiological and kinesiological parameters. All data from force transducers in seat and backrest, torque transducers in the wheels and force transducers in the wheelframes as well as the acquired speed are sampled in a data-acquisition system. An offline curve processor allows the acquired data to be processed with standard or custom-programmed routines. Preliminary results have been added and are discussed.

Engineering↗