Biomedical subjects
Tom A Boon
Publications and source records attributed to Tom A Boon.
Results of permanent prostate brachytherapy, 13 years of experience at a single institution.
BACKGROUND AND PURPOSE: To understand the influence of treatment techniques on the final outcome, as well as the relation of risk groups and of PSA nadir on the outcome, we reviewed our experience over more than 10 years. PATIENTS AND METHODS: Patients were treated in the period 1989 through 2000. Available for this evaluation are 351 patients. The distribution of cases by T stage was T1a, b (9%), T1c (49%), T2 (42%), and by grading G1 (58%), G2 (38%), G3 (1%) and Gx (3%). The technique of plantation of seeds varied over the years, starting with single seeds using a Mick applicator (104 patients), followed by Rapid strands without (70) and with pre-planning (177). Risk groups are categorised as low (iPSA <10 ng/ml, T1-2, grade 1), 116 patients; intermediate (iPSA 10-20 ng/ml, or grade 2-3), 114 patients; and high risk (both factors, or iPSA >20 ng/ml), 121 patients. The mean follow-up time was 50 months, median 48 and range 24-123 months. RESULTS: Overall actuarial survival at 5 and 7 years was 85 and 76%, respectively. Forty patients died, eight (2%) because of or with prostate cancer. Alive are 310 patients (88%), with 223 patients bNED (71%), 51 (16%) with PSA failure, 21 (7%) with local and 15 (5%) with distant recurrence. Total bNED was 72%. Although results are better since the introduction of Rapid strands, 79% bNED versus 54% bNED for single seeds (P = 0.14) also the increase in activity per cm(3) prostate volume accounts for this improvement. With pre-planning a significant better result (P < 0.03) is obtained as compared to single seeds or strands without planning. Categorisation into risk groups results in a significant difference (P < 0.007) of bNED with risk factors, respectively, 57% for the high, 75% for the intermediate and 89% for the low risk group. Also PSA nadir had a significant effect on outcome; patients who reach a nadir of < or =0.5 ng/ml have a 91% chance of cure. CONCLUSIONS: Results of permanent seed implantation improved with the introduction of strands, however, better staging and the increase in activity per cm(3) prostate volume also contributed to this improvement. A significant better result was obtained with pre-planning. Categorisation in risk groups corresponds very well with treatment outcome. Finally, a strong relation is found with PSA nadir.
Noninvasive assessment of prostatic obstruction in elderly men with lower urinary tract symptoms associated with benign prostatic hyperplasia.
OBJECTIVES: To investigate what combination of easily available parameters allows the noninvasive prediction of infravesical obstruction in optimal agreement with urodynamic classification. Urodynamically, men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia are classified as nonobstructed or obstructed. METHODS: Mandatory and recommended tests were performed in 160 consecutive men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia. The classification of the International Continence Society, the group-specific urethral resistance factor, and Schäfer's obstruction grade were estimated from urodynamic studies. The frequency-volume charts were analyzed. A separate group of 173 consecutive men was used for validation. RESULTS: The formula, prostate volume (in cubic centimeters) - 3 x maximal urinary free flow rate (in milliliters per second) - 0.2 x mean voided volume (in milliliters; as estimated from frequency-volume charts), was optimal in the classification compared with the urodynamic classification. Extension of this formula to more than three parameters did not result in better selection. As estimated from receiver operating characteristic curves, the accuracy of the formula appeared to be good. The method of quantifying urethral resistance minimally affected the classification that resulted from the combination. From the results, a diagram was created presenting the probability of an individual to have infravesical obstruction. The validation results were satisfactory. CONCLUSIONS: The prediction of the probability of a man with lower urinary tract symptoms suggestive of benign prostatic hyperplasia to have infravesical obstruction can be deduced from a diagram based on a formula composed of three readily available parameters: prostate volume, maximal urinary free flow rate, and mean voided volume.
Cost aspects of transurethral resection of the prostate, contact laser prostatectomy, and electrovaporization.
OBJECTIVES: To compare the costs of transurethral resection of the prostate (TURP), contact laser prostatectomy (CLP), and electrovaporization in men with lower urinary tract symptoms associated with benign prostatic hyperplasia. METHODS: We conducted a randomized controlled trial that included men with lower urinary tract symptoms who met the criteria of the International Scientific Committee on benign prostatic hyperplasia. Subjective changes were quantified using questionnaires validated by the American Urological Association. The maximal free urinary flow rate was estimated. Morbidity and mortality were registered. These parameters were measured at regular intervals for up to 1 year and once during long-term follow-up. A cost analysis together with a sensitivity analysis was performed on the basis of a follow-up of 12 months. RESULTS: A total of 50 men were randomized to TURP, 45 to laser treatment, and 46 to electrovaporization. The subjective and objective changes were very similar during the 12 months of follow-up. The costs were highest for CLP (1885 dollars), followed by TURP (1707 dollars), and were lowest for electrovaporization (1489 dollars). However, the length of hospital stay decreased during the trial more for CLP and electrovaporization than for TURP. Recalculations demonstrated almost equal costs for CLP and TURP (1697 dollars and 1643 dollars, respectively) and the lowest costs for electrovaporization (1386 dollars). CONCLUSIONS: Electrovaporization has a better cost-effectiveness than CLP and TURP in patients with lower urinary tract symptoms associated with benign prostatic hyperplasia. CLP and TURP showed very similar cost-effectiveness ratios.
Comparison of outcomes of transurethral prostate resection in urodynamicallyobstructed versus selected urodynamicallyunobstructed or equivocal men.
OBJECTIVES: To compare the benefits of transurethral resection of the prostate in urodynamically obstructed versus selected urodynamically unobstructed or equivocal men with severe lower urinary tract symptoms associated with benign prostatic enlargement. METHODS: In this case series study, men with lower urinary tract symptoms were selected if they met the study criteria and underwent the tests recommended by the International Scientific Committee on Benign Prostatic Hyperplasia. They also underwent urodynamic investigations. Men were included when transurethral resection of the prostate was selected as the treatment modality. Of the 132 included subjects, 93 could be re-evaluated 6 months after surgery. RESULTS: Of the 93 re-evaluated men, 59 were obstructed and 34 were unobstructed or equivocal. Both groups were similar with respect to age, symptoms, bother, benign prostatic hyperplasia-impact index, and quality of life. The quantified reductions in symptoms and bother in the unobstructed and equivocal men were about 70% of those reductions in the obstructed men. In the equivocal men, and even in the unobstructed men, a significant reduction with 40% of the urethral resistance occurred. CONCLUSIONS: Transurethral resection of the prostate may be a good treatment alternative for unobstructed or equivocal men with severe lower urinary tract symptoms associated with prostatic enlargement, who opt for resection or who do not respond to or do not tolerate medical therapy.
Long-term follow-up after transurethral resection of the prostate, contact laser prostatectomy, and electrovaporization.
OBJECTIVES: To compare the long-term results of subjective changes, flowmetry, morbidity, and mortality after transurethral resection of the prostate, contact laser prostatectomy, and electrovaporization in men with lower urinary tract symptoms associated with benign prostatic hyperplasia. METHODS: A prospective randomized controlled trial was conducted. Included in the study were men with lower urinary tract symptoms, who met the criteria of the International Scientific Committee on Benign Prostatic Hyperplasia, had a prostate volume between 20 and 65 cm(3), and a Schäfer obstruction grade of 2 or greater. The subjective changes were quantified using the International Prostate Symptom Score, Symptom Problem Index, quality-of-life question, and benign prostatic hyperplasia impact index. Morbidity was registered objectively and by patient questionnaire. Maximal flow was measured by free uroflowmetry. These parameters were measured at regular intervals for up to 1 year. At the end of 2002, all patients were invited for a long-term follow-up examination, including the aforementioned parameters. RESULTS: Fifty men were randomized to undergo transurethral resection of the prostate, 45 laser treatment, and 46 electrovaporization. Of the 50 men, 70% were followed up for a maximum of 7 years. The values for the International Prostate Symptom Score, Symptom Problem Index, quality-of-life score, and benign prostatic hyperplasia impact index increased slightly after a mean follow-up of 4.3 years. The maximal uroflow decreased similarly in all treatment groups to about 150% of the preoperative values. Morbidity, reoperation rates, and mortality were also similar. CONCLUSIONS: This study, with up to 7 years of follow-up, demonstrated durable subjective and objective results for patients with lower urinary tract symptoms associated with benign prostatic hyperplasia after transurethral resection of the prostate, contact laser prostatectomy, or electrovaporization. No clinically relevant differences were found among these modalities.
A randomized controlled trial comparing transurethral resection of the prostate, contact laser prostatectomy and electrovaporization in men with benign prostatic hyperplasia: analysis of subjective changes, morbidity and mortality.
PURPOSE: We analyze subjective changes, morbidity and mortality in men with lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH) after transurethral resection of the prostate, contact laser prostatectomy and electrovaporization. MATERIALS AND METHODS: A prospective, randomized controlled trial was conducted on men with lower urinary tract symptoms, who met the criteria of the International Scientific Committee on BPH, had a prostate volume between 20 and 65 ml., and had Schäfer's obstruction grade 2 or greater. Objective morbidity was recorded for up to 12 months. Subjective morbidity was measured by a questionnaire completed by patients. Subjective changes were quantified using the International Prostate Symptom Score, Symptom Problem Index, Quality of Life question and BPH Impact Index. These indexes and the morbidity questionnaire were measured weekly for the first 6 weeks postoperatively and then at 3, 6 and 12 months. RESULTS: Transurethral prostatic resection was analyzed in 50 men, laser treatment in 45 and electrovaporization in 46. Baseline characteristics, and changes in the symptom scores up to 12 months postoperatively were similar. Perioperative blood loss and perforation were greatest in the resection group, and retention was greatest in the laser group. During the first 6 postoperative weeks there was less pain and less hematuria after resection, and less incontinence after laser prostatectomy. CONCLUSIONS: Subjective changes are similar for transurethral prostatic resection, contact laser and electrovaporization. In the first 6 weeks after treatment there are only slight differences in pain, hematuria and incontinence among the therapies.
Laser prostatectomy in patients on anticoagulant therapy or with bleeding disorders.
PURPOSE: Bleeding disorders or the use of anticoagulant medication are contraindications to transurethral prostate resection in men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). Laser prostatectomy has proved to be adequate surgical therapy with less blood loss than transurethral prostate resection. MATERIALS AND METHODS: A prospective, controlled study was done in patients at high risk (HR) with LUTS suggestive of BPH. They were treated with contact laser prostatectomy (CLP) or the combination of CLP with visual laser ablation prostatectomy (VLAP). HR was defined as bleeding disorders or anticoagulants use. As a control, men at normal risk with LUTS suggestive of BPH were treated with CLP. Patients completed validated questionnaires and underwent urodynamics at baseline and 6 months postoperatively. RESULTS: A total of 75 patients were included, namely 19 in the HR-CLP group, 11 in the HR-CLP-VLAP group and 45 in the normal risk CLP group. Obstruction relief, and symptomatic and subjective improvement were equal in all 3 groups. Effective capacity (maximum cystometric capacity minus post-void residual volume) also improved significantly in all except the HR-CLP group. Maximum urine flow improved in all groups but not significantly in the HR-CLP group. Intraoperative and postoperative complications were slightly higher in HR cases. However, blood transfusion was never necessary and there was no mortality. CONCLUSIONS: CLP and especially CLP-VLAP perform almost as well in HR cases compared with CLP in those at normal risk. These procedures are safe for men at HR with LUTS suggestive of BPH.
Deletion of chromosomal region 6q14-16 in prostate cancer.
A detailed analysis of chromosome 6 in DNAs from prostate cancers was performed, to define a region for subsequent search for cancer genes. DNA from 4 prostate cancer cell lines and 11 xenografts was used for CGH and whole-chromosome allelotyping with polymorphic microsatellite markers. Loss of proximal 6q was studied in more detail by high-density allelotyping of xenografts, cell lines and 19 prostate tumour specimens from TURP. Seven of 15 xenografts and cell lines showed deletion of proximal 6q by CGH. Gain of 6q was found in 2 samples. Six samples showed 6p gain, and 1 had 6p loss. Allelotyping results were consistent with CGH data in 11 of 15 DNAs. In LNCaP and DU145 cells, CGH showed 6p loss and 6q loss, respectively, but 2 allelic bands were detected for many polymorphic markers on these chromosome arms. These apparent discrepancies might be explained by aneuploidy. In cell line TSU, allelotyping demonstrated chromosome 6 deletion, which was not clearly detected by CGH, indicating loss of 1 copy of chromosome 6 followed by gain of the retained copy during progressive tumour growth. Loss of heterozygosity was detected in 9 of 19 TURP specimens. Combining all data, we found a common minimal region of loss at 6q14-16 with a length of 8.6 Mbp flanked by markers D6S1609 and D6S417. One hundred and twenty-three STSs, ESTs, genes and candidate genes mapping in this interval were used to screen xenografts and cell lines for HDs, but none was detected. In summary, chromosome region 6q14-16 was deleted in approximately 50% of the prostate cancer specimens analysed. The high percentage of loss underscores the importance of genes within this region in prostate cancer growth.
Data from frequency-volume charts versus maximum free flow rate, residual volume, and voiding cystometric estimated urethral obstruction grade and detrusor contractility grade in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia.
AIMS: To examine associations of data from frequency-volume charts with maximum free flow rate, residual volume, and voiding cystometric estimated urethral obstruction grade and detrusor contractility in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH). METHODS: The 160 men included in the study met the criteria of the International Scientific Committee on BPH, i.e., they voided more than 150 mL during uroflowmetry, their residual volume and prostate size were estimated, and they completed frequency-volume charts correctly. From the frequency-volume charts, voiding habits and fluid intake were evaluated. Pressure-flow studies were performed as well. RESULTS: Increasing residual volume was related to a decrease of maximum voided volume and to a decrease of maximum free flow rate. Cystometric capacity was little affected by residual volume. Low contractility did not result in high residual volume. A marked decrease in voided volumes with increasing obstruction grade was observed, due to a decrease of cystometric capacity and an increase of residual volume. Detrusor contractility was little associated with voided volumes. A higher voiding frequency was related to a higher fluid intake. However, increased standardized frequency (number of voidings per 1,000 mL) was associated with a substantial reduction of fluid intake. CONCLUSIONS: Infravesical obstruction is the most important factor influencing voided volumes, cystometric capacity, and residual urine volume. Frequency of voiding was not influenced significantly because patients with small voided volumes minimized their fluid intake.
Data from frequency-volume charts versus filling cystometric estimated capacities and prevalence of instability in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia.
The aim was to examine associations of filling cystometric estimated compliance, capacities, and prevalence of bladder instability with data from frequency-volume charts in a well-defined group of men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). Men with LUTS suggestive of BPH were included if they met the criteria of the International Consensus Committee on BPH, i.e., they voided more than 150 mL during uroflowmetry, their residual volume and prostate size were estimated, and they completed frequency-volume charts correctly. From the frequency-volume charts, voiding habits, and fluid intake in the daytime and at night were evaluated. Filling cystometric studies were performed in these men as well. Decreased compliance was an exceptional finding. Cystometric capacity and especially effective capacity (cystometric capacity minus residual volume) corresponded significantly with the maximum voided volume on the frequency-volume charts. Effective capacity was almost twice as high as the average voided volume. Minimum voided volume on frequency-volume charts was not related to filling cystometric data. The presence of instability in the supine or sitting position or in both positions was not significantly associated with smaller voided volumes, higher nocturia, or diuria. Filling cystometric capacities were strongly associated with maximal and mean voided volumes derived from frequency-volume charts. The presence of detrusor instability during filling cystometry did not significantly affect voided volumes, diuria, or nocturia
A randomized controlled trial comparing transurethral resection of the prostate, contact laser prostatectomy and electrovaporization in men with benign prostatic hyperplasia: urodynamic effects.
PURPOSE: We compared urodynamic and uroflowmetry improvements in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH) after transurethral prostate resection, contact laser prostatectomy and electrovaporization. MATERIALS AND METHODS: A prospective randomized controlled trial was performed in men with lower urinary tract symptoms suggestive of BPH who met the criteria of the International Scientific Committee on BPH, had a prostate volume of between 20 and 65 ml., and a Schäfer obstruction grade of 2 or greater. Before and 6 months after treatment urodynamics and free uroflowmetry were performed. RESULTS: A total of 50, 45 and 46 men were randomized to transurethral prostate resection, laser treatment and electrovaporization, respectively. Baseline characteristics were similar in the 3 groups. Detrusor contractility did not change in any of the treatment groups. The average maximum free flow rate increased by a factor of 2.4 after transurethral prostate resection, 2.5 after laser prostatectomy and 2.4 after electrovaporization. The Schäfer obstruction grade decreased by a factor of 0.3 in all groups. Obstruction (Schäfer grade greater than 2) was not noted after transurethral prostate resection or electrovaporization but it was evident in 2 patients after laser prostatectomy. Effective capacity increased by a factor of 1.5 or more. The incidence of detrusor instability was decreased by half in all groups. The incidence of significant post-void residual urine volume decreased in all groups. CONCLUSIONS: There were no significant differences in the improvement in urodynamic and uroflowmetry parameters 6 months after treatment when comparing transurethral prostate resection, contact laser prostatectomy and electrovaporization in men with lower urinary tract symptoms suggestive of BPH.
Correlations of urodynamic changes with changes in symptoms and well-being after transurethral resection of the prostate.
PURPOSE: To establish the predictive value of urodynamics on the outcome of transurethral prostate resection for benign prostatic enlargement we correlated urodynamic changes with symptomatic improvement, decreased bother, and increased general well-being and quality of life after transurethral prostate resection. MATERIALS AND METHODS: Men with lower urinary tract symptoms were selected if they met study criteria and underwent tests recommended by the International Scientific Committee on Benign Prostatic Hyperplasia, and if post-void residual urine volume and prostate size were estimated. Patients answered quality of life, symptom index, symptom problem index and benign prostatic hyperplasia impact index questions. Patients also underwent urodynamic evaluation. Men were included in analysis when transurethral prostate resection was selected as the treatment modality. Of the 132 patients included 93 were reevaluated 6 months after transurethral prostate resection. RESULTS: Improvements after transurethral prostate resection were significantly associated with decreased bladder outlet obstruction (p <0.01). However, 32 cases that were unobstructed or equivocal preoperatively also benefited moderately from resection. Effective capacity, that is cystometric capacity minus post-void residual urine volume, increased by an average of 45% postoperatively. The increase in effective capacity contributed to a significant decrease in symptoms and bother, and to improved well-being. Of the men with a urodynamically proved stable bladder 90% maintained a stable bladder after prostatectomy, while in 50% with a urodynamically proved unstable bladder it became stable postoperatively. CONCLUSIONS: Performing urodynamics preoperatively helps to predict the degree of symptom relief, decreased bother and increased well-being after transurethral prostate resection.