Re: Automated prostate volume determination with ultrasonographic imaging.
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Biomedical subjects
Publications and source records attributed to C H Bangma.
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The correlation between both prostate specific antigen levels (PSA) and prostate specific antigen density (PSAD) and age, prostate volume parameters, body mass index, and the International Prostate Symptom Score (IPSS) were studied in a community-based population. A sample of 502 men aged 55 through 74 years was evaluated, excluding those with a serum PSA above 10 ng/ml, those with biopsy proven prostate cancer, and those who had previously undergone a prostate operation. PSA and PSAD did not correlate with the body mass index. Weak correlations were found between PSA and age (r = 0.25; P < 0.001), PSAD and age (r = 0.17; P < 0.001) and between PSA and the total prostate volume (r = 0.58; P < 0.001). PSA did not correlate independently with age after adjustment for volume (P = 0.22). The finding that PSAD correlates with age (r = 0.17; P < 0.001) is partly explained by the incomplete volume adjustment of PSAD which is proved by the positive correlation between PSAD and prostate volume (r = 0.26; P < 0.001). In the main target age-range for prostate cancer screening there is a poor basis for the use of age-specific reference values or volume adjustment for PSA levels in order to increase the clinical usefulness of this serum marker. Comparison of the results of the present study and studies conducted in others regions shows that there may be significant differences in PSA values per age stratum. Further studies are needed to clarify the reasons for these differences.
Three systemic errors in routine ultrasonic planimetric volume measurements of the prostate were assessed. A computer model using ellipsoids was used to simulate the step section technique and different forms of rotational movements of the prostate during planimetry. The planimetric volume was up to 12% smaller than the exact volume, depending on the degree of rotational movement, the shape, and the length of the ellipsoid. In vivo study of a screening population showed that it is worthwhile to compare caliper length with the number of planimetric steps, as the difference might be an indication of the difference between planimetric and caliper measured volume. In shorter prostates the planimetric volume was smaller than the prolate spheroid volume when compared to longer prostates, as was seen in the computer simulation.
In a screening population of 812 men, between the ages of 55 and 77 years, and prostate-specific antigen (PSA) below 10.0 ng/ml (Hybritech), digital rectal examination (DRE) and transrectal ultrasonography of the prostate (TRUS) were performed. Seventeen prostate carcinomas were detected. Four methods of prostate volumetry were used to determine volume-adjusted PSA levels. These were PSA density for the total gland volume (PSAD), for the inner zone volume (PSAT) and population-specific excess PSA values. There was a significant difference between the benign and the malignant population for age, PSA, PSAD, PSAT and excess PSA values. The maximal discriminatory potential, analysed by the area under receiver ROC curve, was 0.90, reached for prolate spheroid determined excess PSA. For PSA alone this was 0.86. Volume-adjusted PSA values have no additional benefit beyond unadjusted values in screening for prostate carcinoma in this study.
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.
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.
OBJECTIVE: To eliminate the need for per-operative frozen section analysis by using pre-operative serum prostate-specific antigen (PSA), clinical stage and Anderson biopsy grade to predict lymph node metastasis. PATIENTS AND METHODS: Between 1988 and 1994, 214 patients underwent bilateral pelvic lymphadenectomy before an intended retropubic radical prostatectomy for clinically confined prostate carcinoma. Preoperative serum PSA, clinical stage and Anderson biopsy grade were analysed to investigate whether they were able to predict the results of per-operative frozen sections of pelvic lymph nodes. RESULTS: Serum PSA level was the best predictor of a frozen section which was positive for lymph node metastasis, followed by biopsy grade. Clinical T-category combined with PSA level predicted lymph node status less well than did biopsy grade and had no additional value when combined with biopsy grade and PSA. Pre-operative serum PSA combined with biopsy grade predicted a negative frozen section result of bilateral pelvic lymphadenectomy with 95% certainty in at least 17% of patients undergoing radical prostatectomy for clinically confined prostate cancer. Frozen section analysis had a false negative rate of 4.7% when compared with histological staging. Therefore, combining those patients with an estimated 95% chance of a negative frozen section with the group of false negatives, 11 in 214 patients (5.1%) would have undergone radical prostatectomy while having micrometastases. CONCLUSIONS: Selecting men for whom the per-operative frozen section analysis could be omitted may save operating time and allow more efficient use of facilities.
Prostate cancer in most European countries is the second most frequent cancer in males and the second most frequent cause of cancer death. Prostate specific antigen (PSA) is an important tumour marker, which relates to many aspects of this disease. It has been shown that PSA is helpful in the early diagnosis of prostate cancer and in this respect is superior to other available tests like rectal examination and transrectal ultrasonography. PSA is also helpful in staging of locally confined disease. It can be used to identify or exclude local extension of disease, if combined with T category and grade of differentiation determined on biopsy. The same parameters also give an indication of the presence of lymph node metastases, which may prevent unnecessary and invasive staging procedures in certain groups of patients with favourable prognostic factors and a low PSA value. PSA is less suitable as a marker for metastatic disease. Progression of untreated prostate cancer in various stages can be monitored by PSA. The true value of the marker in this respect is still underexplored. It may be possible that PSA will be shown to differentiate effectively between aggressive and non-progressive disease. In this respect, it could become an essential tool to identify those patients that may not require treatment at all. PSA is also a useful marker for therapy response. An elevation of PSA after radical prostatectomy indicates local or metastatic progression, which will occur within 1-2 years. PSA is an androgen dependent enzyme and decreases under endocrine treatment. It is unexplained why in spite of its endocrine dependent character, PSA rises with endocrine independent progression of prostate cancer.
PURPOSE: The contribution of serial prostate specific antigen (PSA) determinations was studied to obtain better understanding of the natural history of clinically confined prostate carcinoma. MATERIALS AND METHODS: Serial PSA determinations in 29 patients with untreated confined prostate carcinoma were correlated to the clinical course for a mean of 39 months. RESULTS: Disease progressed locally in 13 patients after a mean of 31 months. Metastatic progression was not observed. Neither grade, stage, PSA changes nor initial PSA showed significant differences with respect to interval of progression between patients with and without progression. CONCLUSIONS: PSA does not parallel clinical progression in patients selected for watchful waiting.
A case of implantation metastasis in the abdominal wall following transabdominal laparoscopic pelvic lymphadenectomy is reported. A cutaneous nodule was palpated at 1 of the laparoscopic ports 6 months after laparoscopic lymphadenectomy in a 66-year-old patient with stage T3pN1M0, grade 2 adenocarcinoma of the prostate. Aspiration cytology confirmed metastatic adenocarcinoma.
OBJECTIVE: To illustrate the variability of serum Prostate Specific Antigen (PSA) and its causes in relevant clinical patient populations. SETTING: University Hospital Rotterdam, the Netherlands. DESIGN: Descriptive. METHODS: Six different methods of PSA analysis were applied to sera of 19 participants of a screening population, 20 patients after radical prostatectomy, and 15 newly diagnosed patients with a prostate carcinoma. The Hybritech Tandem-R value was chosen as the standard to compare the methods of analysis. Around a standard of 4.0 micrograms/l a range of 3.3 to 7.2 micrograms/l was found; around 10.0 micrograms/l a range of 8.7 to 18.5 micrograms/l. After radical prostatectomy the different methods of analysis agreed completely in only 5 out of 15 patients with respect to serum PSA. CONCLUSION: Because of a considerable variability in serum PSA values between different laboratories and methods of analysis, and of overlap between benign and malignant prostatic diseases, reference values of PSA should be handled with great care.
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Parameters of prostate volume and shape were determined in a community based population of 502 men 55 to 74 years old who had not undergone a previous prostate operation and did not suffer from prostatic cancer. The volumes of the total prostate and of the central relatively hypoechoic area of the prostate were determined. Of all men in this age range 95% had a total prostate volume of more than 20 cm3. Moderate correlations between age and both volume measurements were found (r = 0.26, p < 0.0001 and r = 0.34, p < 0.0001, respectively). The percentage increase per year of central hypoechoic volume (3.5%) was higher than that of total prostatic volume (2%). The average doubling time of total prostatic volume and volume of the central hypoechoic prostate was calculated to be 35 and 20 years, respectively. The roundness of the prostate as expressed by width-to-height ratio at the largest transverse section of the prostate correlated poorly with age (r = -0.13, p = 0.004). The average total prostate volumes as measured by transrectal ultrasound were 21 to 28% higher than reported average volumes measured at autopsy in men in the same age range.
Adenovirus-mediated transduction of the herpes simplex thymidine kinase gene (HSV-tk) in conjunction with ganciclovir (GCV) has been shown to result in significant growth suppression and to enhance survival in a model of mouse prostate cancer. However, this therapeutic activity is not sustained, because in most cases tumors eventually regrow and ultimately cause the death of the host. Androgen ablation, an inducer of apoptosis in prostate cells which is used widely as palliative therapy in patients with prostate cancer, was combined with HSV-tk plus GCV using an androgen-sensitive mouse prostate cancer cell line. The combination of castration and HSV-tk plus GCV led to markedly enhanced tumor growth suppression in both subcutaneous and orthotopic models compared with either treatment alone and resulted in an enhanced survival in which combination-treated animals lived twice as long as controls in the subcutaneous model and over 50% longer than controls in the orthotopic model. Further analysis of apoptotic activity demonstrated high levels of apoptosis only in combined androgen ablation and HSV-tk plus GCV-treated tumors after 14 days of growth in an androgen-depleted environment and 8 days after HSV-tk plus GCV therapy. At this time, the apoptotic index, but not the percent of necrotic tissue, was significantly higher for combination therapy-treated tumors relative to control-treated tumors or either treatment alone. These data indicate that the therapeutic effects of androgen ablation and HSV-tk plus GCV are cooperative and that increased apoptosis may, in part, underlie these activities.