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Bob Djavan

Publications and source records attributed to Bob Djavan.

At least 37 records · Page 2Linked to original sources
PubMed2004

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.

Adenocarcinoma↗
PubMed2004

The Vista system: a new bipolar resection device for endourological procedures: comparison with conventional resectoscope.

OBJECTIVE: Conventional transurethral resection of the prostate (TURP) uses a monopolar electrocautery system in which the current passes from the active electrode through the patient's body towards the return plate and may cause distant negative effects. In this study a new developed resection device, the Vista system, using a bipolar electrocautery system and 0.9% sodium chloride solution for irrigation, was evaluated in an ex-vivo model. METHODS: The modified model of the isolated blood perfused kidney was used to determine cutting qualities, ablation rate, blood loss and coagulation depth of the bipolar resectoscope. After ablating the renal tissue of a perfused kidney in a surface area, blood loss was semiquantitatively determined. Afterwards samples were taken and processed for histological evaluation of the coagulation depth. We compared the new bipolar resection device against a conventional monopolar resectoscope. RESULTS: We found good cutting qualities of the bipolar resectoscope although it is more difficult to start a cut. The ablation rate is determined by the width of the electrode and is similar to the standard device (30 cm(2)/min). The bleeding is reduced with increasing output powers (26.13 +/- 6.15 g/min (level 5); 20.49 +/- 5,47 g/min (level 6); 13.16 +/- 5,47 g/min (level 7); 10.43 +/- 4.76 g/min (level 8) and lower compared to a conventional monopolar resectoscope (17.08 +/- 4.47 g/min). The coagulation depth increases with higher output powers but is reduced compared to the standard device (118 +/- 22 microm (level 5); 121 +/- 23 microm (level 6); 141 +/- 62 microm (level 7); 163 +/- 30 microm (level 8) versus 287 +/- 57 (monopolar resectoscope)). CONCLUSION: Our results with the bipolar resection device for TURP suggest that it may offer an alternative to conventional TURP. As active and the return electrode are placed on the resectoscope, high current densities are achieved locally and complications caused by distant negative effects of the current are theoretically reduced in vivo. Furthermore the risk of TUR syndrome is theoretically eliminated by using physiological sodium chloride solution for irrigation. To prove the clinical significance of our ex-vivo findings, clinical studies including large numbers of patients have to be performed.

Animals↗
PubMed2004

Longitudinal study of men with mild symptoms of bladder outlet obstruction treated with watchful waiting for four years.

OBJECTIVES: To determine the risk of clinical progressions in men with mild lower urinary tract symptoms of bladder outlet obstruction and identify the predictors for progression in this group of men. METHODS: A total of 397 men who presented to the urology clinics with mild symptoms of bladder outlet obstruction (International Prostate Symptom Score less than 8) were analyzed in this longitudinal study conducted during a 4-year period. They began with the watchful waiting protocol and were followed up every 3 months for 48 months. Age, International Prostate Symptom Score (IPSS), divided into obstructive symptom score and irritative symptom score, serum prostate-specific antigen level, total prostate volume, transitional zone volume, urinary flow rates, and postvoid residual urine volume were documented. RESULTS: The cumulative incidence of clinical progression, defined as worsening of the IPSS with migration to the moderate symptom group (IPSS 8 to 18) or severe symptom group (IPSS 19 to 35) and an increase in IPSS of more than 2 points, was 6%, 13%, 15%, 24%, 28%, and 31% at 6, 12, 18, 24, 36, and 48 months, respectively. Nineteen patients (4.9%) developed acute urinary retention within the 48-month follow-up period. Of these 19 patients, only 2 (0.6%) required transurethral resection of the prostate. The variables of importance for disease progression in the artificial neural network analysis were, in order of statistical significance, prostate-specific antigen level, obstructive symptom score, and transitional zone volume. CONCLUSIONS: The risk for men with mild symptoms of bladder outlet obstruction to progress clinically and develop complications such as acute retention of urine is moderate. Prostate-specific antigen, obstructive symptom score, and transitional zone volume were identified as important risk factors.

Aged↗
PubMed2004

Benign prostatic hyperplasia progression and its impact on treatment.

PURPOSE OF REVIEW: Management of men with benign prostatic hyperplasia should reduce the lifetime risk of acute urinary retention and the need for benign prostatic hyperplasia-related surgery. A number of recent studies demonstrate that 5alpha-reductase inhibitors are unique in providing a long-term combination of improvements in symptoms and flow, and reductions in the risks of acute urinary retention and surgical intervention. RECENT FINDINGS: The 5alpha-reductase inhibitor finasteride was shown to reduce the risk of retention and surgery in men with large prostate volumes and/or high PSA. Recent studies have examined the role of adding an alpha1-blocker to 5alpha-reductase inhibitor in short- or long-term combination. The Medical Therapy of Prostatic Symptoms study randomised 3,047 men with benign prostatic hyperplasia to treatment with a 5alpha-reductase inhibitor (finasteride), an alpha1 blocker (doxazosin), a combination of both, or placebo. Only treatment arms containing 5alpha-reductase inhibitor therapy were associated with longer-term significant reductions in the risk of acute urinary retention and invasive therapy for benign prostatic hyperplasia. Three randomised, two-year, placebo-controlled studies have assessed the clinical relevance of the >93% DHT suppression provided by dutasteride. Dutasteride was also associated with a reduction in the risk of acute urinary retention of 57%, and a reduction of 48% in the risk of surgical intervention compared with placebo after 2 years. SUMMARY: Short-term combination of 5alpha-reductase inhibitor and alpha-blockade are optimal in providing symptomatic improvement among patients who require symptom relief, while enabling the initiation of 5alpha-reductase inhibitor therapy to reduce the risk of subsequent acute urinary retention or benign prostatic hyperplasia-related surgery in men who are at greater risk of disease progression.

Adrenergic alpha-Antagonists↗
PubMed2004

Chemotherapeutic prevention studies of prostate cancer.

PURPOSE: Despite advances in the detection and management of prostate cancer, this disease remains a major cause of morbidity and mortality in men. Increasing attention has focused on the role of chemoprevention for prostate cancer, ie the administration of agents that inhibit 1 or more steps in the natural history of prostate carcinogenesis. We review prostate cancer chemoprevention studies in Europe. MATERIALS AND METHODS: Published studies were identified in a search of MEDLINE. Information about ongoing studies was provided by author access to protocols. RESULTS: A variety of chemoprevention studies have focused on the role of dietary factors, vitamins and trace elements in prostate cancer. Some of these studies have been prospective, randomized and double-blinded, while others have used retrospective or epidemiological approaches. Large scale randomized studies are also evaluating the role of 5alpha-reductase inhibitors, which inhibit the conversion of testosterone to the more potent androgen dihydrotestosterone. CONCLUSIONS: Robust evidence is lacking for the value of chemopreventive agents in prostate cancer. Current evidence does suggest that vitamin E and selenium may have a role in prostate cancer chemoprevention. Data from 2 studies, 1 examining the type 1 5alpha-reductase selective inhibitor finasteride and the other using the dual 5alpha-reductase inhibitor dutasteride, will determine the benefits of androgen inhibition strategies for prostate cancer chemoprevention.

Anticarcinogenic Agents↗
PubMed2004

Preventing progression in men with mild symptoms of benign prostatic hyperplasia: a potential role for phytotherapy.

Prevalence of benign prostate hyperplasia (BPH) is increasing with the aging population worldwide. Throughout the 20th century, men with minimally symptomatic BPH were generally advised to defer treatment. Treatment deferral or watchful waiting has always appeared reasonable because mild lower urinary tract symptoms suggestive of bladder outlet obstruction are not bothersome and are often regarded as part of the aging process, progression is usually slow, and symptoms often regress spontaneously. This review examines the evidence of the natural history of BPH, highlighting the group of patients with mild symptoms, the risk factors for progression, and the potential role of phytotherapy in this group of men.

Journal Article↗
PubMed2003

Prevention of prostate cancer with finasteride: US/European perspective.

PURPOSE: Prostate cancer is the most common male cancer, affecting one man in six. Prevention of this disease, even in a subset of patients would have a significant impact on public health. The results of the National Cancer Institute-sponsored Prostate Cancer Prevention Trial demonstrate that finasteride causes a substantial risk reduction across all known risk groups. We herein amplify on the results of this trial to assist patients and physicians in reaching individualized decisions. MATERIALS AND METHODS: The results of the Prostate Cancer Prevention Trial were reviewed. RESULTS: The PCPT demonstrated a 24.8% reduction in prostate cancer risk with the administration of finasteride. High-grade cancers were noted in 6.4% of finasteride patients compared to 5.1% of men receiving placebo. The increase in high-grade tumors was seen within one year of finasteride exposure and did not increase over time. This observation, combined with previous evidence demonstrating an alteration in cytologic and architectural features of prostate cancer with hormonal therapy suggests that the differences in high-grade disease may be an artifact and that application of Gleason grading to these tumors may not be appropriate. DISCUSSION: Men should be presented the benefits and risks of taking finasteride and be assisted in integrating their sexual and urinary symptoms into their decision-making process. Blanket statements for or against the use of this medication ignore patient preferences and differential risk-benefit profiles from finasteride.

Aged↗
PubMed2003

An artificial neural network to predict the outcome of repeat prostate biopsies.

OBJECTIVES: To develop an advanced artificial neural network (ANN) to predict the presence of prostate cancer (PCa) and to predict the outcome of repeat prostate biopsies. The predictive accuracy was compared with the accuracy obtained using standard cutoffs for the free/total (f/t) prostate-specific antigen (PSA) ratio, PSA density (PSAD), PSA density of the transition zone (PSA-TZ), and the total and transition zone volumes. Clinical and biochemical diagnostic tests have been shown to improve PCa detection. When these tests are combined using an ANN, significant increases in specificity at high sensitivity are observed. METHODS: The Vienna-based multicenter European referral database for early PCa detection of 820 men with a PSA level between 4 and 10 ng/mL was used. The presence of PCa was determined using transrectal ultrasound-guided octant needle repeat biopsy. Variables in the database consisted of age, PSA, f/t PSA ratio, digital rectal examination findings, PSA velocity, and the transrectal ultrasound-guided variables of prostate volume, transition zone volume, PSAD, and PSA-TZ. The ANN used in the analysis was an advanced multilayer perceptron selected for accuracy by a genetic algorithm. RESULTS: The repeat biopsy PCa detection rate was 10% (n = 83). At 95% sensitivity, the specificity for ANN was 68% compared with 54%, 33.5%, 21.4%, 14.7%, and 8.3% for multivariate logistic regression analysis, f/t PSA ratio, PSA-TZ, PSAD, and total PSA, respectively. The ANN reduced unnecessary repeat biopsies by 68% in this study. The area under the curve was 83% for the ANN versus 79%, 74.5%, 69.1%, 61.8%, and 60.5% for multivariate analysis, f/t PSA ratio, PSA-TZ, PSAD, and total PSA, respectively. CONCLUSIONS: The current ANN found a strong pattern predictive of PCa in patients with a negative initial biopsy. By combining the individual clinical and biochemical markers into the ANN, 68% specificity at 95% sensitivity was achieved. The ANN allows more accurate and individual counseling of patients with a negative initial biopsy.

Aged↗
PubMed2003

Lower urinary tract symptoms/benign prostatic hyperplasia: fast control of the patient's quality of life.

Fast control of bothersome symptoms and improvement in the patient's quality of life (QOL) are important treatment goals in lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia. Although voiding symptoms are most common, storage symptoms are most bothersome, interfere the most with daily life activities, and have a major effect on QOL. alpha(1)-Adrenoceptor antagonists, such as tamsulosin, improve the most bothersome storage symptoms to roughly the same extent as transurethral resection of the prostate (TURP), whereas the effect on voiding symptoms is slightly less. This may be because tamsulosin relieves storage symptoms as quickly and to the same extent as voiding symptoms, whereas TURP improves storage symptoms to a lesser extent and/or more slowly than voiding symptoms. In addition, alpha(1)-adrenoceptor antagonists have a more rapid onset of action and seem to be slightly more effective in improving LUTS, its bothersomeness, and QOL than 5alpha-reductase inhibitors, such as finasteride. It also seems that alpha(1)-adrenoceptor antagonists have a more rapid onset of action than the plant extract Serenoa repens. Because the alpha(1A)/alpha(1D)-adrenoceptor antagonist tamsulosin has a low risk for symptomatic orthostatic hypotension, it can be initiated at its full therapeutic dose immediately at the start of therapy. This enables faster relief of bothersome LUTS than non-subtype-selective alpha(1)-adrenoceptor antagonists that require dose titration to their full therapeutic dose. In the long term, adding finasteride to an alpha(1)-adrenoceptor antagonist may be beneficial in high-risk patients, but adding S repens does not seem to provide any additional benefit (up to 1 year). In conclusion, monotherapy with an alpha(1A)/alpha(1D)-adrenoceptor antagonist, such as tamsulosin, provides very effective and rapid relief of bothersome LUTS and so enables a rapid improvement of the patient's QOL.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2003

When to biopsy and when to stop biopsying.

With the widespread use of serum prostate-specific antigen (PSA) and transrectal ultrasound-guided needle biopsy of the prostate in men with suspected prostate cancer, physicians are faced with the dilemma of treating a patient with a high index of suspicion of prostate cancer but with an initial set of negative biopsies. For the initial biopsy, the optimal number of biopsy cores for detecting prostate cancer in prostate biopsy remains controversial; it is also often unclear who should undergo a repeat prostatebiopsy and when to stop biopsying.

Biopsy, Needle↗
PubMed2003

PSA progression following radical prostatectomy and radiation therapy: new standards in the new Millennium.

Prostate-specific antigen (PSA) progression following radical treatments of clinically localized prostate cancer is a common problem facing both the patient and the urologist. Not all patients with relapsing disease have an equal risk of death due to prostate cancer. After surgery, biochemical failure can be defined as persisting detectable levels of PSA after radical prostatectomy or a PSA rise after a period of normalization. On the other hand, definitions of PSA progression after radiation therapy vary and no clear consensus can be found. This review of the recent international literature updates the knowledge about the diagnostic procedures used in relapsing patients. Predictors of progression are precised leading to a better patient selection, based on currently available tables and nomograms. Indeed, identification of high risk patients may allow a more appropriate treatment decision. After radical treatment, the analysis of time to recurrence, PSA doubling time, PSA kinetics combined to modern imaging techniques such as 111In capromab penditide scan may allow a better identification of the recurrence site. Thus, an optimal treatment strategy may be envisaged such as local irradiation, salvage surgery, hormone therapy or combinations for which indications and results are provided. Alternative options such as cryotherapy still need further investigation. At last, the use of artificial neural networks will certainly enhance the selection of patients submitted to radical treatments as well as the selection of relapsing patients to allow a more appropriate adjuvant therapy.

Antibodies, Monoclonal↗
PubMed2003

Artificial neural networks for decision-making in urologic oncology.

The authors are presenting a thorough introduction in Artificial Neural Networks (ANNs) and their contribution to modern Urologic Oncology. The article covers a description of Artificial Neural Network methodology and points out the differences of Artificial Intelligence to traditional statistic models in terms of serving patients and clinicians, in a different way than current statistical analysis. Since Artificial Intelligence is not yet fully understood by many practicing clinicians, the authors have reviewed a careful selection of articles in order to explore the clinical benefit of Artificial Intelligence applications in modern Urology questions and decision-making. The data are from real patients and reflect attempts to achieve more accurate diagnosis and prognosis, especially in prostate cancer that stands as a good example of difficult decision-making in everyday practice. Experience from current use of Artificial Intelligence is also being discussed, and the authors address future developments as well as potential problems such as medical record quality, precautions in using ANNs or resistance to system use, in an attempt to point out future demands and the need for common standards. The authors conclude that both methods should continue to be used in a complementary manner. ANNs still do not prove always better as to replace standard statistical analysis as the method of choice in interpreting medical data.

Humans↗
PubMed2003

An artificial neural network for prostate cancer staging when serum prostate specific antigen is 10 ng./ml. or less.

PURPOSE: An artificial neural network was developed to improve the prediction of pathological stage before radical prostatectomy based on variables available at biopsy and clinical parameters. MATERIALS AND METHODS: We used the prospectively accrued European prostate cancer detection data base to train an artificial neural network to predict pathological stage in 200 men with serum prostate specific antigen (PSA) 10 ng./ml. or less who underwent radical prostatectomy. Variables included in the artificial neural network were patient age, serum PSA, free-to-total PSA ratio, PSA velocity, transrectal ultrasound calculated total and transition zone volumes with their associated PSA parameters (transition zone PSA density and PSA density), digital rectal examination and Gleason score on biopsy. Two multilayer perceptron neural networks were trained on the remaining variables. Data on the 200 patients were divided randomly into a training set, a test set and a validation or prospective set. RESULTS: Overall classification accuracy of the artificial neural network was 92.7% and 84.2% for organ confined and advanced prostate cancer staging, respectively. For preoperatively predicting local versus advanced stage the area under the ROC curve for the artificial neural network was significantly larger (0.91) compared with logistic regression analysis (0.83), Gleason score (0.69), PSA density (0.68), prostate transition zone volume (0.63) and serum PSA (0.62) (all p <0.01). CONCLUSIONS: The artificial neural network outperformed logistic regression analysis and correctly predicted pathological stage in more than 90% of the validation patients with serum PSA 10 ng./ml. or less based on clinical, biochemical and biopsy data. In the future artificial neural networks may represent a significant step for improved staging of prostate cancer when counseling patients referred for radical prostatectomy or other curative treatments.

Adult↗
PubMed2003

Local active warming: an effective treatment for pain, anxiety and nausea caused by renal colic.

PURPOSE: Based on previous studies showing that warming decreases trauma pain in emergency care we hypothesized that local active warming of the abdomen and lower back region could decrease pain in acute renal colic cases during emergency transport. MATERIALS AND METHODS: After obtaining informed consent 100 patients were divided into 2 groups, including those who received active warming of the abdomen and lower back region (42C) and those who received no warming. Pain, nausea and anxiety were rated by the patients using visual analog scales. Statistical evaluation was performed using the t test with p <0.05 considered significant. RESULTS: In group 1 a significant pain decrease was recorded in all cases using a visual analog score (VAS) (82.7 +/- 9.5 to 36.3 +/- 16.0 mm VAS, p <0.01). In group 2 patient pain scores remained comparable (81.8 +/- 13.0 to 80.6 +/- 12.3 mm VAS). In group 1 anxiety significantly decreased (79.0 +/- 8.9 and 30.7 +/- 14.1 mm VAS before and after treatment, respectively, p <0.01). In group 2 a nonsignificant change in score was noted (79.7 +/- 20.5 to 75.2 +/- 19.7 mm VAS). In group 1 a significant decrease in nausea was recorded in all cases (85.7 +/- 11.2 to 40.6 +/- 23.0 mm VAS, p <0.01). In group 2 patient nausea scores remained comparable (79.2 +/- 22.0 to 80.3 +/- 22.4 mm VAS, respectively). CONCLUSIONS: Local active warming is an effective and easy to learn pain treatment for patients with acute renal colic in emergency care.

Adult↗