Long-term prognostic value of dobutamine stress 99mTc-sestamibi SPECT: single-center experience with 8-year follow-up

PURPOSE: To determine the role of magnetic resonance (MR) imaging performed with a combined endorectal body phased-array coil for patients with elevated prostate-specific antigen (PSA) levels or suspicious free-to-total PSA ratios in whom prior transrectal ultrasonographically (US) guided biopsy findings were negative for prostate cancer. MATERIALS AND METHODS: Forty-four patients with PSA levels greater than 4 ng/mL or free-to-total PSA ratios lower than 15% but negative biopsy findings were examined with T1- and T2-weighted MR imaging at 1.5 T with a combined endorectal body phased-array coil. All patients underwent digital rectal examination (DRE) and transrectal US. Thirty-eight patients underwent repeat biopsy after MR imaging. The accuracy of MR imaging for detection of prostate cancer was assessed prospectively. Retrospectively, MR imaging findings were correlated with individual biopsy site findings. MR imaging and biopsy results were correlated by using a cross table to calculate sensitivity, specificity, and positive predictive value (PPV). Retrospective analysis results were evaluated with receiver operating characteristic analysis. A P value of less than.05 indicated significance (chi(2) test according to Pearson). RESULTS: At prospective analysis, MR imaging had a sensitivity of 83% and a PPV of 50% for detection of prostate cancer; these values were 33% and 67%, respectively, for DRE and 33% and 57%, respectively, for transrectal US. At retrospective site-by-site analysis, MR imaging results did not correlate significantly with individual biopsy site findings (P =.126); sensitivity was 65% and PPV was 12%. CONCLUSION: In this patient population, MR imaging has higher sensitivity for detection of prostate cancer than DRE or transrectal US.     

Predictors of prostate carcinoma: accuracy of gray-scale and color Doppler US and serum markers

PURPOSE: To determine the accuracy of detecting prostate cancer by using (a) gray-scale and color Doppler transrectal ultrasonography (US), (b) serum and excess prostate-specific antigen (PSA) levels, and (c) targeted and sextant transrectal US-guided biopsy. The relationship between US-detected neovascularity and tumor biologic activity was also evaluated. MATERIALS AND METHODS: Between 1995 and 1999, 544 patients with elevated PSA levels and/or abnormal digital rectal examination underwent transrectal US-guided sextant biopsy and targeted biopsy of US abnormalities. Sensitivity, specificity, and accuracy of gray-scale US, color Doppler US, targeted biopsy, and PSA and excess PSA were calculated. RESULTS: Gray-scale US depicted 78 (41.1%) of 190 cancers, whereas color Doppler US depicted 30 (15.8%) additional cancers. Targeted biopsy was used to detect 108 (56.8%) cancers, whereas sextant biopsy was used to detect 82 (43.2%) additional cancers. Although US-visible cancers had a higher Gleason grade than did cancers discovered at sextant biopsy (P <.05), 25 of the 66 cancers identified with sextant biopsy alone were Gleason grade 6 or higher. Color Doppler US-depicted hypervascularity correlated with biologically aggressive tumors. Excess PSA was normal in 58 (30.5%) cancers, with an accuracy of 67.3%, resulting in better prediction of prostate tumors than with serum PSA level alone. CONCLUSION: Gray-scale transrectal US, even coupled with color Doppler US, is inadequate for prostate carcinoma screening; therefore, targeted biopsy should always be accompanied by complete sextant biopsy sampling.     

Importance of specific prostatic antigen to prostatic volume ratio in the selection of patients for ultrasonography-guided biopsy of the prostate]

US-guided biopsy was performed in 94 patients with suspected lesions at transrectal US. Histology demonstrated carcinoma in 43 cases, benign hyperplasia in 44, and prostatitis in 7. In all cases the prostate specific antigen (PSA) was calculated, by means of US, together with prostatic volume (V). PSA was related to the corresponding gland volume, which resulted in PSA/V index. Subsequently, histology was correlated with both PSA value and PSA/V ratio. Our study showed PSA/V ratio to have higher sensitivity and specificity than absolute PSA value in the diagnosis of prostatic carcinoma. The authors believe prostate US-guided biopsy to be: a) necessary when the suspected area has PSA/V ratio greater than 0.15, and especially when PSA/V greater than 0.30; b) not indicated when echostructural alterations are associated with PSA/V less than 0.15, because they are most frequently due to benign lesions. The combined use of PSA/V ratio and US is therefore suggested to select the patients in whom biopsy is to be performed.     

Multiple prostatic biopsies in the "gray zone" of the specific prostatic antigen

PURPOSE: Aim of our study was to identify cases of undetected prostatic cancer in patients with normal findings at digital examination and transrectal US, and prostate specific antigen (PSA) values ranging 4-10 ng/mL. MATERIAL AND METHODS: Two hundred and ninety patients were submitted to transrectal US and random bilateral prostatic biopsy; 3 samples were collected from each side of the gland using 16-Gauge thru-cut needles. Of the 290 patients who gave fully informed consent, we selected 34 whose age ranged 56 to 76 years (mean: 64). Inclusion criteria were PSA 4-10 ng/mL, PSAD cut-off 0.15, free/total PSA ratio 15-25%, and normal findings at digital examination and transrectal US. PSA velocity was calculated collecting 3 blood samples every 30 days for 2 months. RESULTS: Five of the 34 selected patients (15%) had prostatic cancer, and 2 (6%) Pin (1 Pin 1 and 1 Pin 2). As for the other 27 patients, biopsy demonstrated 4 (12%) cases of prostatitis and 23 (62%) cases of BPH. PSA values increased in all patients with positive histology, versus only 6 (22%) of those with negative histology. PSAD was 0.15 or greater in 3 of 7 prostatic cancer patients. Free/total PSA ratio never exceeded the cut-off value. Gleason score ranged 2 to 4. CONCLUSIONS: Our findings confirm that prostatic biopsy can detect tumors also in areas which appear normal at transrectal US and digital examination, and that PSA rate increases in patients with positive histology. Finally, the actual clinical role of prostatic biopsy relative to all other diagnostic imaging techniques remains to be defined.     

Correlation between Doppler vascular density and PSA response to radiation therapy in patients with localized prostate carcinoma

RATIONALE AND OBJECTIVES: The authors performed this study to ascertain whether there is a correlation between pretreatment Doppler vascular density (DVD) of the prostate and prostate-specific antigen (PSA) response following radiation therapy in prostate cancer patients. MATERIALS AND METHODS: Prior to radiation therapy, 14 patients with biopsy-proven carcinoma (of Gleason grades 2-7) were imaged with transrectal ultrasound in gray-scale, color Doppler, and power Doppler modes. The Doppler images were analyzed for mean DVD with the aid of a computer program. PSA levels were measured before therapy and every 3 months after therapy. The PSA measurements were fitted to an exponential to determine PSA halving time (T1/2). Correlations were made between T1/2 and the following pretherapy measurements: mean DVD, PSA level, prostate volume, and Gleason grade. RESULTS: Median follow-up time was 392 days. A linear correlation with regression coefficient (R) of 0.75-0.80 was observed between mean DVD and T1/2 for color Doppler and power Doppler imaging. In both imaging modes, each percentage increase in mean DVD led to an increase in T1/2 by 25 days. Pretherapy prostate volume, PSA level, and Gleason score did not correlate with T1/2. CONCLUSION: The pretreatment mean DVD correlates inversely with the rate of posttherapy decline in PSA in patients with prostate cancer. That is, pretreatment vascularity prognosticates postirradiation PSA response. The mechanism underlying this correlative relationship is not known.     

Integrated CT-perfusion shows no meaningful correlation with PSA and presurgical Gleason score in patients with early prostate cancer

ObjectivesTo analyze the correlation of computed tomography (CT) perfusion parameters blood flow (BF), blood volume (BV), and mean transit time (MTT) with presurgical prostate cancer data.MethodsNinety-eight patients with biopsy-proven prostate cancer underwent a CT-perfusion scan of the prostate. MTT, BF, and BV were determined and correlated with prostate-specific antigen (PSA) level, tumor load and Gleason score of transrectal ultrasonography-guided biopsy specimens.ResultsMean BF was 41.3 ml/100 ml*min^- 1, BV 5.2 ml/100 ml, MTT 8.7 s. Moderate correlations were observed between Gleason score and BF (0.35) and between PSA and BF (0.33) and BV (0.30).ConclusionsCT-perfusion shows no valuable correlation with presurgical prostate cancer data.     

New ultrasound technologies for the diagnostics of prostate cancer

CLINICAL/METHODOLOGICAL ISSUE: Prostate cancer is the most common cancer in men. The diagnosis is based on prostate-specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasound (TRUS) guided biopsy. These techniques have considerable limitations, which result in unnecessary biopsies. Furthermore the biopsies are associated with morbidity and costs. STANDARD RADIOLOGICAL METHODS: Standard gray-scale ultrasound has a low sensitivity and specificity for prostate cancer detection. METHODOLOGICAL INNOVATIONS: New ultrasound technologies, including color- and power Doppler ultrasound, contrast enhanced US and real-time sonoelastography have shown to improve prostate cancer diagnosis. PERFORMANCE: Contrast-enhanced ultrasound has shown a sensitivity of 100% (95% CI, 95%), a negative predictive value (NPV) of 99.8% and a positive predictive value (PPV) of 88.8% for prostate cancer detection. Real-time sonoelastography has shown a sensitivity of 86%, a specificity of 81% and NPV of 91% for prostate cancer diagnosis. ACHIEVEMENTS: Most studies show that these new ultrasound modalities demonstrate a 1.5 to 2.5 times higher detection of prostate cancer per biopsy specimen compared with systematic biopsy. Multicenter studies results are at present lacking but are, however ongoing. PRACTICAL RECOMMENDATIONS: In patients with suspected prostate cancer (elevated PSA, suspicious DRE) these new ultrasound techniques should be used. These techniques can detect prostate cancer and allow a targeted biopsy approach.     

The value of a baseline bone scan in patients with newly diagnosed prostate cancer.

PURPOSE: This study evaluated the role of bone scans in managing newly diagnosed, untreated prostate cancer. METHODS: Two hundred seventy consecutive staging bone scans in patients (mean age, 69 years) with newly diagnosed prostate cancer who had serum prostate-specific antigen (PSA) determinations and biopsies between January 1995 and October 1997 were evaluated retrospectively. RESULTS: The bone scans were positive for metastatic bone disease in 24 patients and negative in 246. Serum PSA levels, the number of positive biopsy cores, the extent of tumor in the prostate gland, and Gleason scores were all significantly correlated with scintigraphic bone metastases (P < 0.0001 for each). Of the 177 patients with PSA levels less than 10 ng/ml, three had bone metastases. Bone metastases were found in 2 of 34 patients with PSA levels of 10.1 to 20 ng/ml, in 3 of 29 patients with PSA values of 20.1 to 50 ng/ml, and in 16 of 30 patients with PSA levels greater than 50.1 ng/ml. Only one patient had a bone metastasis when the prostate cancer involved fewer than 2 biopsy cores (1 of 135) or when disease was confined to one lobe (1 of 131), but the incidence increased significantly when the malignancy involved three or more biopsy cores (20 of 114) or disease was present in both prostate lobes (20 of 118). Four of 160 patients with Gleason scores less than 6 had bone metastases, whereas 20 of 110 patients with Gleason scores greater than 7 had bone metastases. CONCLUSIONS: The likelihood of bone metastases is low in patients with newly diagnosed, untreated prostate cancer when the initial PSA level was less than 10 ng/ml, the number of positive biopsy cores was less than 2, tumor was confined to one lobe, or the Gleason score was less than 6. However, none of these criteria can be used to exclude metastatic bone disease. A baseline bone scan is an important staging procedure and should be obtained to provide maximum data for clinical management of the disease.     

Effects of androgen deprivation on prostatic morphology and vascular permeability evaluated with mr imaging

PURPOSE: To assess magnetic resonance (MR) measures of vascular permeability of prostate cancer treated with androgen deprivation and to correlate these with morphologic appearances and serum prostate-specific antigen (PSA) levels. MATERIALS AND METHODS: MR examinations in 56 consecutive patients with prostate cancer were performed before and after luteinizing hormone-releasing hormone analog treatment. T2-weighted and contrast medium-enhanced T1-weighted MR images were obtained. Pre- and posttreatment comparisons of morphologic features, glandular volume, and enhancement-related parameters (capillary permeability, leakage space, gadolinium accumulation) were made. RESULTS: Fifty-five tumors were seen before treatment; 42, after treatment. Signal intensity in the peripheral zone and seminal vesicles decreased on T2-weighted images in 42 (75%) and 25 (45%) patients, respectively. Median volume in tumor decreased by 65% (95% CI: 55%, 76%); in central gland, by 30% (95% CI: 25%, 35%). Reductions in tumor permeability (P <.001) and changes in washout patterns were observed (P <.001). Tumor permeability reductions coincided with a decrease in serum PSA levels in 91% of patients. A weak correlation between tumor permeability and volume change was seen (r = 0.55, P =.04). Reductions in peripheral zone (P <.001) and central gland (P =.009) permeability were noted. CONCLUSION: Androgen deprivation decreases tumor volume and vascular permeability and impairs detection of prostate cancers. Use of MR estimates of permeability may be an additional way of assessing prostatic tumor response to antiandrogen treatment.     

Likelihood of prostate cancer based on prostate-specific antigen density by MRI: retrospective analysis

OBJECTIVE: As a screening test for prostate cancer (PCA), prostate-specific antigen (PSA) may induce unnecessary prostate biopsy in patients with PSA 4.1-10.0 ng/ml. PCA detection may be delayed in patients with PSA < or =4.0 ng/ml. MRI-based PSA density of the prostate (PSAD) and of the prostatic transitional zone (PSAT) could improve differentiation of PCA and benign prostatic hyperplasia. MATERIAL AND METHODS: Total prostate and transitional zone volumes were planimetrically determined in axial, T2-weighted fast spin echo MR images of the prostate. Serum PSA concentration was measured with an automated standardized microparticle enzyme immune assay. PSAD and PSAT were calculated in 17 patients with clinically significant PCA and 42 patients with benign prostatic hypertrophy (BPH) (66 +/- 6 versus 64 +/- 8 years, p = 0.2410, t test) who had PSA levels < or =10.0 ng/ml. RESULTS: For differentiation of BPH and PCA, PSA alone above the optimal cutoff level of 4.2 ng/ml showed an odds ratio for PCA of 6.7 (95% confidence interval [CI], 1.9-23.2). PSAD showed an odds ratio for PCA of 71.3 (95% CI, 11.8-430.9) above the optimal cutoff level of 0.07 ng/ml/cc. PSAT demonstrated an odds ratio for PCA of 320.0 (95% CI, 27.1-3781.4) above the optimal cutoff level of 0.15 ng/ml/cc. CONCLUSIONS: In patients with PSA < or =10.0 ng/ml, MRI-based PSAD and PSAT appear to improve differentiation of prostate cancer and BPH and are feasible to reduce the frequency of unnecessary prostate biopsy.     

Neue Ultraschalltechnologien f��r die Diagnostik des Prostatakarzinoms

Clinical/methodological issue

Prostate cancer is the most common cancer in men. The diagnosis is based on prostate-specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasound (TRUS) guided biopsy. These techniques have considerable limitations, which result in unnecessary biopsies. Furthermore the biopsies are associated with morbidity and costs.

Standard radiological methods

Standard gray-scale ultrasound has a low sensitivity and specificity for prostate cancer detection.

Methodological innovations

New ultrasound technologies, including color- and power Doppler ultrasound, contrast enhanced US and real-time sonoelastography have shown to improve prostate cancer diagnosis.

Performance

Contrast-enhanced ultrasound has shown a sensitivity of 100% (95% CI, 95%), a negative predictive value (NPV) of 99.8% and a positive predictive value (PPV) of 88.8% for prostate cancer detection. Real-time sonoelastography has shown a sensitivity of 86%, a specificity of 81% and NPV of 91% for prostate cancer diagnosis.

Achievements

Most studies show that these new ultrasound modalities demonstrate a 1.5 to 2.5 times higher detection of prostate cancer per biopsy specimen compared with systematic biopsy. Multicenter studies results are at present lacking but are, however ongoing.

Practical recommendations

In patients with suspected prostate cancer (elevated PSA, suspicious DRE) these new ultrasound techniques should be used. These techniques can detect prostate cancer and allow a targeted biopsy approach.     

Correlations between the various methods of estimating prostate volume: transabdominal, transrectal, and three-dimensional US.

OBJECTIVE: To evaluate the correlations between prostate volumes estimated by transabdominal, transrectal, and three-dimensional US and the factors affecting the differences. MATERIALS AND METHODS: The prostate volumes of 94 consecutive patients were measured by both transabdominal and transrectal US. Next, the prostate volumes of 58 other patients was measured by both transrectal and three-dimensional US. We evaluated the degree of correlation and mean difference in each comparison. We also analyzed possible factors affecting the differences, such as the experiences of examiners in transrectal US, bladder volume, and prostate volume. RESULTS: In the comparison of transabdominal and transrectal US methods, the mean difference was 8.4 +/- 10.5 mL and correlation coefficient (r) was 0.775 (p < 0.01). The experienced examiner for the transrectal US method had the highest correlation (r = 0.967) and the significantly smallest difference (5.4 +/- 3.9 mL) compared to the other examiners (the beginner and the trained; p < 0.05). Prostate volume measured by transrectal US showed a weak correlation with the difference (r = 0.360, p < 0.05). Bladder volume did not show significant correlation with the difference (r = -0.043, p > 0.05). The comparison between the transrectal and three-dimensional US methods revealed a mean difference of 3.7 +/- 3.4 mL and the correlation coefficient was 0.924 for the experienced examiner. Furthermore, no significant difference existed between examiners (p > 0.05). Prostate volume measured by transrectal US showed a positive correlation with the difference for the beginner only (r = 0.405, p < 0.05). CONCLUSION: In the prostate volume estimation by US, experience in transrectal US is important in the correlation with transabdominal US, but not with three-dimensional US. Also, less experienced examiners' assessment of the prostate volume can be affected by prostate volume itself.     

The clinical utility of prostate-specific antigen and bone scintigraphy in prostate cancer follow-up.

To assess the value of serum prostate-specific antigen (PSA) in prostate cancer follow-up, we prospectively studied 107 consecutive patients with: (1) pathologically confirmed prostate cancer; (2) definitive prostatectomy and/or radiation therapy greater than or equal to 3 mo prior to bone scanning; and (3) one bone scan and serum PSA sampling within 3 mo of each other. The mean and range of patient follow-up since definitive therapy was 1.6 and 0.5-8 yr, respectively. Abnormal bone scans were correlated with pertinent radiographs. Of 107 bone scans, 16 demonstrated metastatic bone disease. A PSA value of less than or equal to 8 ng/ml excluded bone metastases with a predictive value of a negative test of 98.5%. Without radiographic correlation, abnormal bone scans rarely represented metastases if the PSA value was less than or equal to 8 ng/ml. In summary, serum PSA concentration determines the need for follow-up bone scanning and assists in scan interpretation in patients status post definitive therapy for prostate cancer.     

Nonpalpable cancer of the prostate: assessment with transrectal US

Palpable cancer of the prostate is widely believed to be clinically significant. The authors compared the clinical significance of palpable prostate cancer with nonpalpable prostate cancer discovered with transrectal ultrasound (US). A strong association between lesion volume measured with preoperative transrectal US and volumetric measurements in 60 radical prostatectomy specimens permitted the use of tumor size measured with transrectal US as a reasonable estimation of gross tumor volume. In a subsequent clinical series, 147 biopsy-proved cancers were grouped according to size measured at US, the findings at digital rectal examination (DRE), and the Gleason score. For the 147 patients with known prostate cancer, a statistically significant difference between Gleason scores of palpable and nonpalpable cancers could not be demonstrated when the size of the tumor and its location within the prostate were held constant. Assuming that the Gleason score is a reliable indication of malignant potential and clinical significance, the authors conclude that nonpalpable prostatic cancer detected with transrectal US alone may be just as clinically significant as prostatic cancer discovered with DRE.     

Monitoring of prostate-specific antigen during external beam radiotherapy for carcinoma of the prostate.

In 35 patients with histologically confirmed carcinoma of the prostate confined to the pelvis, the value of prostate-specific antigen (PSA) was evaluated during external beam radiotherapy to the prostate and draining pelvic lymph nodes. In eleven patients initial prostate-specific antigen levels were more than 10 ng/ml and in twelve patients between 4 and 10 ng/ml. In the remaining twelve, initial prostate-specific antigen levels were less than 4 ng/ml. In the course of radiotherapy we could see a significant decrease of the prostate-specific antigen, even in those with levels between 4 and 10 ng/ml. This decrease seems to follow a logarithmic course but, because only three measurements during radiotherapy were made, this needs further study. With higher levels (more than 20 ng/ml), we rarely saw a value of less than 10 ng/ml at the end of radiotherapy but had to wait for several months for lower values to be reached. In several cases prostate-specific antigen decrease took up to three months after the end of the radiation course. Our results indicate that prostate-specific antigen values actually start decreasing during the radiation course itself and may, therefore, be useful for monitoring response to radiotherapy.     

社区中老年人群前列腺疾病筛查的价值

目的探讨联合应用经直肠超声(TRUS)、前列腺特异性抗原(PSA)和直肠指检(DRE)方法筛查前列腺癌的意义。方法 2010年1月—2012年3月,对来社区卫生中心就诊的325例45～80岁男性,联合应用TRUS、PSA及DRE方法,观察前列腺疾病的分布情况;三者均为阳性作为前列腺癌高风险者行前列腺穿刺活检。结果 325例中,前列腺增生、前列腺结石、前列腺囊肿及前列腺癌分别为256例(78.77%)、33例(10.16%)、31例(9.53%)和5例(1.54%)。前列腺增生和前列腺结石在不同年龄分布差异具有统计学意义(P<0.05);与临床前列腺癌组比较,本组B期以下早期癌占80%,临床组B期以下早期癌只占26.47%,且多为偶发癌;转移癌的诊断率筛查组低于临床组,临床组低分化癌的比率高于筛查组(P均<0.05)。结论社区中老年男性体检中,进行以TRUS、PSA及DRE为主的筛查,是早期发现前列腺癌的最佳途径,对临床早期诊疗具有重要的指导意义。     

Prostatic biopsy directed with endorectal MR spectroscopic imaging findings in patients with elevated prostate specific antigen levels and prior negative biopsy findings: early experience

PURPOSE: To prospectively evaluate the accuracy of transrectal ultrasonography (US)-guided biopsy directed with magnetic resonance (MR) spectroscopic imaging in patients with an elevated prostate specific antigen (PSA) level and negative findings at prior biopsy by using subsequent biopsy results as the reference standard. MATERIALS AND METHODS: The committee on human research approved this study, and written informed consent was obtained. MR imaging and MR spectroscopic imaging were performed in 42 men (age range, 45-75 years; average age, 63.3 years; median age, 65 years) with negative findings at two or more prostatic biopsies and at digital rectal examination. MR spectroscopic data were rated on a scale of 1 (benign) to 5 (malignant) on the basis of standardized metabolic criteria. Abnormal voxels were overlaid on the corresponding transverse transrectal US images and used to perform voxel-guided biopsy of the prostate. All patients subsequently received an extended-pattern biopsy scheme. RESULTS: Thirty-one of 42 patients demonstrated metabolic abnormalities that were suspicious for cancer (voxels with scores > or = 4). Eleven patients with negative MR spectroscopic imaging results also had negative biopsy findings. Cancer was detected in 17 (55%) of 31 men with positive MR spectroscopic imaging findings (voxels with scores > or = 4) with a sensitivity of 100%, specificity of 44%, positive predictive value of 55%, negative predictive value of 100%, and accuracy of 67%. In men with at least one spectroscopic voxel with a score of 5 (12 of 17 men), the sensitivity, specificity, positive and negative predictive values, and accuracy were 71%, 84%, 75%, 81%, and 79%, respectively. CONCLUSION: Metabolic data from MR spectroscopic imaging can be transferred to transrectal US images and used to sample regions of cancer in men with rising PSA levels and negative findings at prior biopsy with good accuracy.     

Diagnostic and prognostic value of serum prostate specific antigen in prostate carcinoma

The upper normal limit of serum prostate specific antigen (PSA) of 4 ng/ml is positively evaluated since it discriminates a large percentage of patients having prostate cancer. The PSA limit of 2.5 ng/ml may be used accordingly for patients younger than 50 years of age. The PSA range of 3.3-4 ng/ml may indicate a percentage of patients positive for prostate carcinoma. The PSA above 10 ng/ml indicates that patients have prostate carcinoma by more than 50 %, which is more than double as compared to patients having PSA limits between 4.1-10 ng/ml. It is important to repeat doubtful PSA tests after 3-4 months. If within a year an increase in PSA of more than 2 ng/ml is detected, a high risk of death from prostate cancer is expected. The time for doubling PSA values within a year is described as "velocity index". As for free PSA, this test is not often applied in many nuclear medicine centers. According to the Mayo Clinic, USA, instructions, when total PSA is 2-3.9 ng/ml and free PSA above 18% of these values, the possibility of prostate cancer is less than 10%. On the contrary, for the above total PSA values, if free PSA is less than 10% of these values, the possibility of prostate cancer increases to more than 30%. It is suggested that PSA values be expressed per g of prostate tissue in order to relate to prostate volume. However, one should have in mind that prostate carcinomas have less PSA per g than hyperthophic glands and their volume is usually larger. There are cases where treatment of prostate hypertrophy with finasteride or treatment of prostate cancer with anticancer drugs, may induce a false low PSA. More information about the practical importance of PSA values is expected after 2 or 3 years when a study by the National Cancer Institute of USA on 74,000 men will be completed.     

Local recurrence after radical prostatectomy: correlation of US features with prostatic fossa biopsy findings

PURPOSE: To evaluate the diagnostic accuracy of transrectal ultrasonography (US) in the detection of local recurrence following radical prostatectomy. MATERIALS AND METHODS: Ninety-nine patients with biochemical recurrence after radical prostatectomy were evaluated at transrectal US and prostatic fossa biopsy. Location of suspected recurrence at transrectal US and clinical features, such as prostate-specific antigen levels and digital rectal examination findings, were correlated with biopsy results. RESULTS: Forty-one (41%) of 99 cases of local recurrence were detected. The percentage of sites of lesions identified at transrectal US and corresponding positive biopsy rates were as follows: the urethrovesical anastomotic area, 56% and 61%; bladder neck, 26% and 54%; retrovesical space, 4% and 100%; and more than one site, 14% and 71%. By comparing transrectal US and digital rectal examination, the sensitivities were 76% and 44% (P =.007), while specificities were 67% and 91% (P =.004), respectively. An increased positive biopsy rate with increasing prostate-specific antigen levels was noted (P =.04). CONCLUSION: Transrectal US is more sensitive but less specific than digital rectal examination in the detection of local recurrence. Biopsy findings in more than half of the suspected lesions at the urethrovesical anastomotic area and bladder neck were positive. Lesions in the retrovesical space, although less frequently encountered, had a high likelihood of representing cancer recurrence.     

Localized prostate cancer: use of serial prostate-specific antigen measurements during radiation therapy.

The serum half-life of prostate-specific antigen (PSA) after radical prostatectomy is about 3 days; to the authors' knowledge, the PSA half-life during radiation therapy (RT) has not been investigated with weekly serial measurements. To determine the rate of decline and the half-life of PSA, serial measurements were obtained during 6-8 weeks of external-beam RT for localized prostate cancer. PSA values were determined immediately before and approximately 24 hours after the first dose of RT; thereafter, weekly measurements were made. There was a downward trend in PSA levels in 19 patients, with a median half-life of 58.5 days; the mean decline was 1.6% per day. However, in four patients, PSA levels either rose and fell to pre-RT values or increased steadily. The effect of digital rectal examination (DRE) on PSA levels was also analyzed. When the dates of DRE and subsequent PSA levels were inspected, no increase in PSA levels subsequent to DRE was found, although three of the four patients in whom PSA levels did not decrease underwent multiple DREs. The authors found a statistically significant (P = .023) transient elevation in the mean PSA values after the first fraction of RT (2 Gy) was administered; the mechanism and importance of which are not known.