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

Simultaneous noninvasive ultrasensitive detection of prostate specific antigen and lncRNA PCA3 using multiplexed dual optical microfibers with strong plasmonic nanointerfaces

Low accuracy of diagnosing prostate cancer (PCa) was easily caused by only assaying single prostate specific antigen (PSA) biomarker. Although conventional reported methods for simultaneous detection of two specific PCa biomarkers could improve the diagnostic efficiency and accuracy, low detection sensitivity restrained their use in extreme early-stage PCa clinical assay applications. In order to overcome above drawbacks, this paper herein proposed a multiplexed dual optical microfibers separately functionalized with gold nanorods (GNRs) and Au nanobipyramids (Au NBPs) nanointerfaces with strong localized surface plasmon resonance (LSPR) effects. The sensors could simultaneously detect PSA protein biomarker and long noncoding RNA prostate cancer antigen 3 (lncRNA PCA3) with ultrahigh sensitivity and remarkable specificity. Consequently, the proposed dual optical microfibers multiplexed biosensors could detect the PSA protein and lncRNA PCA3 with ultra-low limit-of-detections (LODs) of 3.97 × 10-15 mol/L and 1.56 × 10-14 mol/L in pure phosphorus buffer solution (PBS), respectively, in which the obtained LODs were three orders of magnitude lower than existed state-of-the-art PCa assay technologies. Additionally, the sensors could discriminate target components from complicated physiological environment, that showing noticeable biosensing specificity of the sensors. With good performances of the sensors, they could successfully assay PSA and lncRNA PCA3 in undiluted human serum and urine simultaneously, respectively. Consequently, our proposed multiplexed sensors could real-time high-sensitivity simultaneously detect complicated human samples, that providing a novel valuable approach for the high-accurate diagnosis of early-stage PCa individuals.

Multiparametric ultrasound of prostate: role in prostate cancer diagnosis

Recent advances in ultrasonography (US) technology established modalities, such as Doppler-US, HistoScanning, contrast-enhanced ultrasonography (CEUS), elastography, and micro-ultrasound. The early results of these US modalities have been promising, although there are limitations including the need for specialized equipment, inconsistent results, lack of standardizations, and external validation. In this review, we identified studies evaluating multiparametric ultrasonography (mpUS), the combination of multiple US modalities, for prostate cancer (PCa) diagnosis. In the past 5 years, a growing number of studies have shown that use of mpUS resulted in high PCa and clinically significant prostate cancer (CSPCa) detection performance using radical prostatectomy histology as the reference standard. Recent studies have demonstrated the role mpUS in improving detection of CSPCa and guidance for prostate biopsy and therapy. Furthermore, some aspects including lower costs, real-time imaging, applicability for some patients who have contraindication for magnetic resonance imaging (MRI) and availability in the office setting are clear advantages of mpUS. Interobserver agreement of mpUS was overall low; however, this limitation can be improved using standardized and objective evaluation systems such as the machine learning model. Whether mpUS outperforms MRI is unclear. Multicenter randomized controlled trials directly comparing mpUS and multiparametric MRI are warranted.

Hypoehoic lesions on Transrectal Ultrasound and its correlation to Gleason grade in the diagnosis of Clinically Significant Prostate Cancer: A Prospective Study

Context The importance of hypoechoic lesions on transrectal ultrasound (TRUS) merits re-assessment in the present era of widespread prostate-specific antigen (PSA) testing.

Aims We aimed to investigate the predictive accuracy of hypoechoic lesions on TRUS of prostate in the diagnosis of prostate cancer and to examine the association of hypoechoic lesions with the aggressiveness of prostate cancer.

Settings and Design This prospective study was conducted in a tertiary care center in South India from November 2017 to December 2019.

Methods and Material We included 151 patients undergoing TRUS-guided 12-core prostate biopsy in view of raised serum PSA with or without suspicious digital rectal examination (DRE) findings in the study. Age, DRE findings, serum PSA level, TRUS findings, and histopathology reports were documented. These were compared between patients with and without hypoechoic lesions on TRUS.

Statistical Analysis Used The statistical analysis for this study was performed using SPSS v20.0 software.

Results Among 151 men, prostate cancer was diagnosed in 68 (45.03%) with mean age at presentation 69.81 ± 6.49 years. Fifty-eight cases (38.41%) had hypoechoic lesion on TRUS and the cancer detection rate (68.96%) amongst this group was significantly higher than in those without hypoechoic lesion ( p <0.0001). Patients with hypoechoic lesion were more likely to have higher grade cancer. Abnormal DRE findings and hypoechoic lesion on TRUS were independent predictors of a clinically significant cancer ( p <0.05).

Conclusion Hypoechoic lesion on TRUS can be considered as an indicator of clinically significant prostate cancer.

Imaging of Neuroendocrine Prostatic Carcinoma

Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer that typically has a high metastatic potential and poor prognosis in comparison to the adenocarcinoma subtype. Although it can arise de novo, NEPC much more commonly occurs as a mechanism of treatment resistance during therapy for conventional prostatic adenocarcinoma, the latter is also termed as castration-resistant prostate cancer (CRPC). The incidence of NEPC increases after hormonal therapy and they represent a challenge, both in the radiological and pathological diagnosis, as well as in the clinical management. This article provides a comprehensive imaging review of prostatic neuroendocrine tumors.

How to Improve TRUS-Guided Target Biopsy following Prostate MRI

TRUS is a basic imaging modality when radiologists or urologists perform cognitive fusion or image fusion biopsy. This modality plays the role of the background images to add to an operator's cognitive function or MRI images. Operators need to know how to make TRUS protocols for lesion detection or targeting. Tumor location, size, and shape on TRUS are different from those on MRI because the scan axis is different. TRUS findings of peripheral or transition tumors are not well known to radiologists and urologists. Moreover, it remains unclear if systematic biopsy is necessary after a tumor is targeted. The purpose of this review is to introduce new TRUS protocols, new imaging features, new biopsy techniques, and to assess the necessity of systematic biopsy for improving biopsy outcomes.

Tumor contact length of prostate cancer determined by a three-dimensional method on multiparametric magnetic resonance imaging predicts extraprostatic extension and biochemical recurrence

OBJECTIVE

To evaluate the clinical benefit of tumor contact length as a predictor of pathological extraprostatic extension and biochemical recurrence in patients undergoing prostatectomy.

METHODS

A total of 91 patients who underwent 3T multiparametric magnetic resonance imaging before prostatectomy from April 2014 to July 2019 were included. A total of 94 prostate cancer foci were analyzed retrospectively. We evaluated maximum tumor contact length, which was determined to be the maximum value in the three-dimensional directions, as a predictor of pathological extraprostatic extension and biochemical recurrence.

RESULTS

A total of 19 lesions (20.2%) had positive pathological extraprostatic extension. Areas under the curves showed maximum tumor contact length to be a significantly better parameter to predict pathological extraprostatic extension than the Prostate Imaging Reporting and Data System (P = 0.002), tumor maximal diameter (P = 0.001), prostate-specific antigen (P = 0.020), Gleason score (P < 0.001), and clinical T stage (P < 0.001). Multivariate analysis showed maximum tumor contact length (P = 0.003) to be an independent risk factor for predicting biochemical recurrence. We classified the patients using preoperative factors (prostate-specific antigen >10, Gleason score >3 + 4 and maximum tumor contact length >10 mm) into three groups: (i) high-risk group (patients having all factors); (ii) intermediate-risk group (patients having two of three factors); and (iii) low-risk group (patients having only one or none of the factors). Kaplan-Meier curves showed that the high-risk group had significantly worse biochemical recurrence than the intermediate-risk group (P = 0.042) and low-risk group (P < 0.001).

CONCLUSIONS

Our findings suggest that maximum tumor contact length is an independent predictor of pathological extraprostatic extension and biochemical recurrence. A risk stratification system using prostate-specific antigen, Gleason score and maximum tumor contact length might be useful for preoperative assessment of prostate cancer patients.

Sensors for diagnosis of prostate cancer: Looking beyond the prostate specific antigen

Prostate cancer represents one of the most common forms of cancer affecting men across the globe. Due to late diagnosis of this disease, the mortality of this condition is very high. Conventional diagnostic methods like the direct rectal examination are uncomfortable and, in most cases, delayed, and further confirmation is required with biopsies and Gleason score. The most common biomarker approved by the FDA (United States Food and Drug Administration) is the prostate specific antigen (PSA) that is detected by conventional biochemical assays which require expensive reagents, is time-consuming and more often is only indicative and cannot be considered confirmative as it is susceptible to erroneous conclusions. The prostate health index employs quantification of PSA in its free and bound forms to enumerate the risk of prostate cancer and has found acceptance with clinicians though the methods used to determine these quantities are slow and require additional sensitivity. Search for novel biomarkers other than PSA has resulted in the identification of several promising candidates. However, their detection is still heavily dependent upon conventional biochemical assays that retain the challenges of being time-consuming, poorly sensitive and expensive. Development of specific sensor technologies integrating nanomaterials offers a viable alternative for rapid and sensitive determination of these non-PSA markers. This review summarizes the major advances in the development of sensors for diagnosis of prostate cancer using non-PSA markers. It also highlights some of the emerging paradigms in cancer diagnosis that may transform the diagnostic field in the context of prostate cancer.

Automatic cancer tissue detection using multispectral photoacoustic imaging

PURPOSE

In the case of multispecimen study to locate cancer regions, such as in thyroidectomy and prostatectomy, a significant labor-intensive processing is required at a high cost. Pathology diagnosis is usually done by a pathologist observing tissue-stained glass slide under a microscope.

METHOD

Multispectral photoacoustic (MPA) specimen imaging has proven successful in differentiating photoacoustic (PA) signal characteristics between a histopathology-defined cancer region and normal tissue. This is mainly due to its ability to efficiently map oxyhemoglobin and deoxyhemoglobin contents from MPA images and key features for cancer detection. A fully automated deep learning algorithm is purposed, which learns to detect the presence of malignant tissue in freshly excised ex vivo human thyroid and prostate tissue specimens using the three-dimensional MPA dataset. The proposed automated deep learning model consisted of the convolutional neural network architecture, which extracts spatially colocated features, and a softmax function, which detects thyroid and prostate cancer tissue at once. This is one of the first deep learning models, to the best of our knowledge, to detect the presence of cancer in excised thyroid and prostate tissue of humans at once based on PA imaging.

RESULT

The area under the curve (AUC) was used as a metric to evaluate the predictive performance of the classifier. The proposed model detected the cancer tissue with the AUC of 0.96, which is very promising.

CONCLUSION

This model is an improvement over the previous work using machine learning and deep learning algorithms. This model may have immediate application in cancer screening of the numerous sliced specimens that result from thyroidectomy and prostatectomy. Since the instrument that was used to capture the ex vivo PA images is now being developed for in vivo use, this model may also prove to be a starting point for in vivo PA image analysis for cancer diagnosis.

Dynamic 11C-Choline PET / CT for the primary diagnosis of prostate cancer

OBJECTIVES

To test the ability of dynamic 11C-PET / CT to discriminate cancerous tissue from background tissue in patients with localized prostate cancer.

MATERIALS AND METHODS

Twenty-four consecutive patients with prostate cancer were prospectively evaluated with dynamic 11C-choline PET / CT prior to radical prostatectomy. The PET / CT scan was divided into 18 sequences of 5 seconds each, followed by 9 sequences of 60 seconds each. Whole-mount sections of harvested prostates served as reference standards. Volumes of interest were positioned on the dynamic PET / CT images and the following quantitative variables were calculated: perfusion coefficient (K1), washout constant (K2), area under the curve (AUC) at 175 and 630 seconds, and average and maximum standardized uptake values (SUVavg, and SUVmax). Wilcoxon signed-ranks test was used to compare benign and cancerous areas of the prostate.

RESULTS

Areas of cancerous tissue were characterized by higher SUVavg and SUVmax than areas of benign tissue (3.67 ± 2.7 vs. 2.08 ± 1.3 and 5.91 ± 4.4 vs. 3.71 ± 3.7, respectively, P < 0.001), in addition to a higher K1 (0.95 ± 0.58 vs. 0.43 ± 0.24, P < 0.001) and greater cumulative tracer uptake, represented by the AUC at 175 and 630 seconds (P <0.001). No associations were found between dynamic parameters and preoperative prostate specific antigen level or Gleason score.

CONCLUSIONS

In this pilot study, 11C-choline PET / CT demonstrated increased tracer uptake with higher values of static and dynamic parameters in areas of prostate cancer compared to areas of benign tissue. Larger studies are warranted to validate these results and examine the potential applicability of 11C-choline dynamic PET / CT for the diagnosis of prostate cancer.

The predictive efficacy of hypoechoic lesion in ultrasound for prostate cancer in Chinese people: five-year experience in a moderated 10-core transperineal prostate biopsy procedure

We aim to investigate the predictive efficacy of hypoechoic lesion for prostate cancer at different levels of serum PSA in the procedure of transrectal ultrasound guided 10-core trans-perineal prostate biopsy (TP-PBx). In this study, we collected clinical parameters involving age, digital rectal examination (DRE), PSA, prostate volume, pathological diagnosis, Gleason score, novel Gleason group, and numbers of positive cores from 856 patients who had elevated level of PSA above 4 ng/ml or susceptible nodule of prostate gland in DRE received the moderated 10-core TP-PBx procedure. There were 481 cases (56.2%) with no visible lesion of hypoechoic nodule in transrectal ultrasound (TRUS) and 375 cases (43.8%) with the hypoechoic lesion. The total cancer detection rate is 45.56%. The predictive efficacy of hypoechoic lesion for prostate cancer varies among different PSA intervals. For PSA groups of 0-4, 4-10, 10-20, 20-100, > 100 ng/ml, the Youden's indexes are 0.3483, 0.3506, 0.3941, 0.2795 and 0.8667, respectively. Besides, the visible lesions are inclined to be detected in patients with higher Gleason score. We concluded that the hypoechoic lesions in TRUS could improve the predictive accuracy for diagnosing prostate cancer and present different predictive efficacy in the respective PSA intervals. Besides, it was probably associated with more aggressive clinical significance.

Utility of Ultrasound in the Diagnosis, Treatment, and Follow-up of Prostate Cancer: State of the Art

Prostate cancer screening currently consists of serum prostate-specific antigen and digital rectal examination, followed by transrectal ultrasound-guided biopsy for diagnostic confirmation. Although the current paradigm of prostate cancer screening has led to a decrease in advanced disease and cancer-related mortality, these techniques have limitations in terms of sensitivity and specificity, resulting in missed cancers that are clinically significant and the overdetection of clinically insignificant cancers. New imaging techniques and technologies are required to improve the detection of prostate cancer. This article summarizes the use of novel ultrasound techniques and technologies in the detection, biopsy, and treatment of prostate cancer.

Results of multiparametric transrectal ultrasound-based focal high-dose-rate dose escalation combined with supplementary external beam irradiation in intermediate- and high-risk localized prostate cancer patients

PURPOSE

Clinical results of a biologic information-based focused dose escalation combined with dose de-escalation for the whole organ in external beam radiotherapy + high-dose-rate brachytherapy (HDR-BT) boost application for localized prostate cancer in a consecutively treated patient cohort.

METHODS AND MATERIALS

One hundred thirty patients were treated with external beam radiotherapy (50 Gy) complementary to two multiparametric transrectal ultrasound-guided 15 Gy HDR-BT fractions. Real-time multiparametric transrectal ultrasound-based biologic planning for high-dose-rate boost dose planning used the summation of gray scale and Doppler sonography imaging + biopsy information. Target subvolumes received HDR-BT dose escalation up to 60 Gy/fraction. Dose-volume histogram parameters, organ at risks doses, and toxicity results were investigated.

RESULTS

The median followup was 4.3 years, the median age was 68.62 years, and the mean initial prostate-specific antigen was 18.69 ng/mL. Low-, intermediate-, and high-risk constituted 69%, 21%, and 10% of the patients, respectively. The mean peripheral dose was 3.9 Gy per fraction. Prostate-specific antigen nadir was in 93% of the patients ≤1 ng/mL. Quality parameters were as follows: D₉₀: 6.58 Gy, V₁₀₀: 30.36%, V₁₅₀: 9.96%, V₂₀₀: 3.16%, uD_0.1: 7.34 Gy, uD₂: 9.34 Gy, rD₀₁: 10.56 Gy, and rD₂: 8.32 Gy, respectively. We observed G1, G2, G3 urinary toxicity in 17/130, 11/130, and 2/130 patients, respectively. Rectal toxicity: G1 and G2 occurred in 19/130 and 2/130 patients with mean dose values G1: 8.2 Gy and G2: 8.76 Gy. Analysis of variance test resulted in no correlation between toxicities and any other investigated factors.

CONCLUSIONS

Focused extreme dose escalation with low prostate mean peripheral dose results in excellent long-term outcome data and very high focal boost doses and is causing no enhancement in late treatment toxicity.

Limiting overdiagnosis of low-risk prostate cancer through an evaluation of the predictive value of transrectal and power Doppler ultrasonography

PURPOSE

Overdiagnosis induced by prostate cancer screening makes necessary a better selection of candidate patients for prostate biopsy. The objective of our study is to assess the probability of having a high- or low-risk lesion that could require active surveillance (AS) after biopsies and a normal or abnormal examination, including transrectal and power Doppler ultrasonography (TRUS-PDS).

METHODS

Four hundred and twenty-nine consecutive patients with a PSA level <10 ng/ml and a normal digital rectal examination (DRE) had guided biopsies in a prospective study. We used D'Amico's criteria to assess the risk of a biological recurrence and Dall'Era's criteria to assess possible AS. The TRUS-PDS was considered positive if one biopsy was positive in the same sextant as the suspect image.

RESULTS

One hundred and seventy-seven out of 429 (41 %) T1c cancers were diagnosed; 131 out of 177 (74 %) could be qualified as low risk, and 119 out of 177 (67 %) could require AS. The TRUS-PDS was normal in 285 of 429 patients (66 %). With a normal TRUS-PDS, the probability of not having cancer with a high or intermediate risk was 96 % (negative predictive value). With an abnormal TRUS-PDS, the probability of having a positive biopsy was 59 %, and the probability of having a significant cancer was 30 %, according to the Dall'Era criteria. When TRUS-PDS was normal, these probabilities significantly decreased to 32 and 5 %, respectively (p < 0.01).

CONCLUSIONS

Patients with a PSA level <10 ng/ml, a normal DRE, and a normal TRUS-PDS have a less than 5 % risk of high- or intermediate-risk cancer.

Transrectal Elastographic Biopsy and Contrast-Enhanced Transrectal Biopsy May Offer Improvements Over the Current Transrectal Systemic Biopsy Technique

Prostate cancer is a common cause of cancer-related death of men in the United States. The purpose of this review is to compare the validity of transrectal ultrasound–guided systemic biopsy with contrast-enhanced transrectal ultrasound–guided systemic biopsy and transrectal elastography–guided systemic biopsy for the detection of prostate cancer. Adding contrast-enhanced or transrectal elastography core targeting to transrectal ultrasound–guided biopsy is a feasible approach to increase detection rates of higher-grade prostate cancers. Because contrast-enhanced imaging of the prostate is not approved for use in the United States, elastography is the most effective sonographic solution to improve prostate cancer detection with current screening techniques.

Prospective evaluation of prostate with transrectal spectral Doppler with biopsy correlation: a clinicopathologic study

OBJECTIVES

To compare the transrectal (TR) spectral Doppler findings between benign prostatic hyperplasia group and prostate cancer group.

METHODS

All the patients were assessed for adequate preparation, and informed consent was obtained prior to the procedure. The control group (n = 33) comprised patients who were negative for malignancy on biopsy. The study group (n = 22) were positive for malignancy and were also divided into three groups on the basis of the Gleason score. Study parameters included mean values for resistive index (RI), pulsatality index (PI), systolic/diastolic ratio (S/D) and peak systolic velocity (PSV). These were separately measured for bilateral capsular and urethral branches and compared between groups. In patients with unilateral tumour, these were compared between the tumour and non-tumour sides. Finally, the parameters were compared with patient's age. Mann-Whitney U test was used to evaluate the statistical significance.

RESULTS

The mean values of RI, PI, S/D and PSV were found to be 0.84/1.03, 1.8/1.99, 3.93/4.45 and 15.52/16.15 cm s(-1), respectively, in the control and study groups which were not statistically significant. In patients with unilateral malignancy (n = 16), there was no significant difference from the non-tumour side. Doppler parameters showed statistically significant relationships with age. The mean of minimum RI was found to be 0.60 in patients less than 60 years of age and 0.76 in patients more than or equal to 60 years of age in the benign category (p-value = 0.014). The PI and S/D also showed significant difference in the benign category.

CONCLUSION

TR spectral Doppler parameters did not reveal any significant difference in patients with or without prostatic malignancy, irrespective of the Gleason grade. Doppler parameters, however, showed significant correlation with age and were lower in younger patients.

ADVANCES IN KNOWLEDGE

TR spectral Doppler is unlikely to emerge as a diagnostic and prognostic tool for prostate carcinoma.

Multiparametric ultrasound in the detection of prostate cancer: a systematic review

PURPOSE

To investigate the advances and clinical results of the different ultrasound modalities and the progress in combining them into multiparametric UltraSound (mpUS).

METHODS

A systematic literature search on mpUS and the different ultrasound modalities included: greyscale ultrasound, computerized transrectal ultrasound, Doppler and power Doppler techniques, dynamic contrast-enhanced ultrasound and (shear wave) elastography.

RESULTS

Limited research available on combining ultrasound modalities has presented improvement in diagnostic performance. The data of two studies suggest that even adding a lower performing ultrasound modality to a better performing modality using crude methods can already improve the sensitivity by 13-51 %. The different modalities detect different tumours. No study has tried to combine ultrasound modalities employing a system similar to the PIRADS system used for mpMRI or more advanced classifying algorithms.

CONCLUSION

Available evidence confirms that combining different ultrasound modalities significantly improves diagnostic performance.

Prevalence and Risk Factors of Prostate Cancer in Chinese Men with PSA 4-10 ng/mL Who Underwent TRUS-Guided Prostate Biopsy: The Utilization of PAMD Score

Purpose. To elucidate the characteristics and risk factors for positive biopsy outcomes in Chinese patients with prostate specific antigen (PSA) 4–10 ng/mL and develop a risk-stratification score model. Methods. The data of 345 patients who underwent transrectal ultrasound-guided prostate biopsy between 2011 and 2013 was retrospectively analyzed. Digital rectal examination (DRE), prostate volume (PV), magnetic resonance imaging (MRI), and smoking status were also collected. Positive biopsy outcomes were defined as prostate cancer (PCa) and high grade PCa (HGPCa, Gleason Score ≥ 7). Results. The median PSA was 7.15 (IQR 5.91–8.45) ng/mL. Overall 138 patients (40.0%) were shown to have PCa, including 100 patients (29.0%) with HGPCa. Smaller PV, elder age, MRI results, and positive DRE were proved to be predictive factors for positive biopsy outcomes in both univariate and multivariate analysis. We developed a “PAMD” score which combined the four factors to categorize patients into three risk groups, and the model performed good predictive sensitivity and specificity. Conclusion. The prevalence of prostate cancer in Chinese patients with PSA 4–10 ng/mL was 40%, including 29% patients with high grade disease. DRE, age, MRI, and PV were predictive factors for positive biopsy outcomes, and the PAMD score model could be utilized for risk-stratification and decision-making.

The role of transrectal ultrasound in the diagnosis of prostate cancer: new contributions

Objective

The present study was aimed at evaluating the contribution of transrectal prostate ultrasound in the screening for prostate neoplasias and in the guidance of prostate biopsies.

Materials and Methods

Prospective study developed over a one-year period. All the patients with indication for prostate biopsy were evaluated. Regardless of PSA values, the patients underwent ultrasound in order to identify suspicious nodules (confirmed by two observers). Sextant biopsy was subsequently performed. In cases of finding suspicious nodules, an additional puncture directed to such nodules was done.

Results

In a total of 155 cases the prevalence of malignancy was of 53%. Suspicious nodules were detected in 34 patients, and 25 where malignant (positive predictive value of 74%). The specificity and sensitivity for suspicious nodules were 88% and 31% respectively. Comparatively with the randomly obtained sextant specimens, the rate of findings of neoplasia was higher in the specimens obtained with puncture directed to the nodule (p = 0.032). No statistically significant difference was observed in the Gleason score for both types of specimens (p = 0.172).

Conclusion

The high positive predictive value and the high rate of findings of neoplasia in specimens of suspicious nodules should be taken into consideration in the future. The authors suggest a biopsy technique similar to the one described in the present study (sextant biopsy plus puncture directed to the suspicious nodule).

3-Tesla magnetic resonance imaging improves the prostate cancer detection rate in transrectral ultrasound-guided biopsy

The detection rate of prostate cancer (PCa) using traditional biopsy guided by transrectal ultrasound (TRUS) is not satisfactory. The aim of this study was to determine the utility of 3-Tesla (3-T) magnetic resonance imaging (MRI) prior to TRUS-guided prostate biopsy and to investigate which subgroup of patients had the most evident improvement in PCa detection rate. A total of 420 patients underwent 3-T MRI examination prior to the first prostate biopsy and the positions of suspicious areas were recorded respectively. TRUS-guided biopsy regimes included systematic 12-core biopsy and targeted biopsy identified by MRI. Patients were divided into subgroups according to their serum prostate-specific antigen (PSA) levels, PSA density (PSAD), prostate volume, TRUS findings and digital rectal examination (DRE) findings. The ability of MRI to improve the cancer detection rate was evaluated. The biopsy positive rate of PCa was 41.2% (173/420), and 41 of the 173 (23.7%) patients were detected only by targeted biopsy in the MRI-suspicious area. Compared with the systematic biopsy, the positive rate was significantly improved by the additional targeted biopsy (P=0.0033). The highest improvement of detection rate was observed in patients with a PSA level of 4–10 ng/ml, PSAD of 0.12–0.20 ng/ml², prostate volume >50 ml, negative TRUS findings and negative DRE findings (P<0.05). Therefore, it is considered that 3-T MRI examination could improve the PCa detection rate on first biopsy, particularly in patients with a PSA level of 4–10 ng/ml, PSAD of 0.12–0.20 ng/ml², prostate volume of >50 ml, negative TRUS findings and negative DRE findings.

Limited evidence for the use of imaging to detect prostate cancer: a systematic review

OBJECTIVE

To assess the diagnostic accuracy of imaging technologies for detecting prostate cancer in patients with elevated PSA-values or suspected findings on clinical examination.

METHODS

The databases Medline, EMBASE, Cochrane, CRD HTA/DARE/NHS EED and EconLit were searched until June 2013. Pre-determined inclusion criteria were used to select full text articles. Risk of bias in individual studies was rated according to QUADAS or AMSTAR. Abstracts and full text articles were assessed independently by two reviewers. The performance of diagnostic imaging was compared with systematic biopsies (reference standard) and sensitivity and specificity were calculated.

RESULTS

The literature search yielded 5141 abstracts, which were reviewed by two independent reviewers. Of these 4852 were excluded since they did not meet the inclusion criteria. 288 articles were reviewed in full text for quality assessment. Six studies, three using MRI and three using transrectal ultrasound were included. All were rated as high risk of bias. Relevant studies on PET/CT were not identified.

CONCLUSION

Despite clinical use, there is insufficient evidence regarding the accuracy of imaging technologies for detecting cancer in patients with suspected prostate cancer using TRUS guided systematic biopsies as reference standard.

Transrectal electrical impedance tomography of the prostate: spatially coregistered pathological findings for prostate cancer detection

PURPOSE

Prostate cancer ranks as one of the most common malignancies and currently represents the second leading cancer-specific cause of death in men. The current use of single modality transrectal ultrasound (TRUS) for biopsy guidance has a limited sensitivity and specificity for accurately identifying cancerous lesions within the prostate. This study introduces a novel prostate cancer imaging method that combines TRUS with electrical impedance tomography (EIT) and reports on initial clinical findings based on in vivo measurements.

METHODS

The ultrasound system provides anatomic information, which guides EIT image reconstruction. EIT reconstructions are correlated with semiquantitative pathological findings. Thin plate spline warping transformations are employed to overlay electrical impedance images and pathological maps describing the spatial distribution of prostate cancer, with the latter used as reference for data analysis. Clinical data were recorded from a total of 50 men prior to them undergoing radical prostatectomy for prostate cancer treatment. Student's t-tests were employed to statistically examine the electrical property difference between cancerous tissue and benign tissue as defined through histological assessment of the excised gland.

RESULTS

Example EIT reconstructions are presented along with a statistical analysis comparing EIT and pathology. An average transformation error of 1.67% is found when 381 spatially coregistered pathological images are compared with their target EIT reconstructed counterparts. At EIT signal frequencies of 0.4, 3.2, and 25.6 kHz, paired-testing demonstrated that the conductivity of cancerous regions is significantly greater than that of benign regions ( p < 0.0304).

CONCLUSIONS

These preliminary clinical findings suggest the potential benefits electrical impedance measurements might have for prostate cancer detection.

Doppler spectral waveform parameters at neurovascular bundle vessels in patients with prostate biopsy

INTRODUCTION AND OBJECTIVES

There is a need to improve prescreening determination of prostate cancer to better select patients who need biopsy. Such a strategy properly implemented, will decrease the number of negative biopsies for prostate cancer and in turn better balance the risks and morbidity for patients recommended for biopsy. The aim of study is to investigate Doppler spectral waveform parameters of neurovascular bundle (NVB) vessels and determine differences between benign and malignant pathologies.

PATIENTS AND METHODS

We performed a prospective analysis involving 292 patients who received prostate biopsy for elevated prostate-specific antigen (PSA) values or abnormal digital rectal examination, as well as 174 patients with symptomatic benign prostatic hyperplasia. Doppler spectral waveform (DSW) parameters (peak-systolic velocity [PSV], end-diastolic velocity [EDV], and resistive index [RI]) were measured at bilateral NVB vessels through Doppler transrectal ultrasound at the right lateral decubitus position, compared, and analyzed among patients with benign versus malignant histology for each side.

RESULTS

Overall, both PSV and EDV at malignant sides were significantly higher than those at benign sides, as well as lower RI (all p-values <0.05, unpaired t-test). In subgroup analysis with 93 patients of serum PSA between 10 and 20 ng/mL and 56 patients with one-side malignancy, higher EDV and lower RI were significantly associated with malignancies (all p<0.05). The values of PSV and EDV rather than RI might be influenced by the patients' position and RI by the prostate volume.

CONCLUSIONS

In this study, DSW parameters (mainly EDV and RI) at NVB vessels were significantly associated with prostate cancer, particularly in patients with serum PSA of 10-20 ng/mL. It should be in caution that the patients' position and prostate volume may influence the Doppler signal as demonstrated in the current study. These findings can provide more diagnostic information before prostate biopsy.

Transrectal quantitative shear wave elastography in the detection and characterisation of prostate cancer

BACKGROUND

Shear wave imaging (SWI) is a new ultrasound technique whose application facilitates quantitative tissue elasticity assessment during transrectal ultrasound biopsies of the prostate gland. The aim of this study was to determine whether SWI quantitative data can differentiate between benign and malignant areas within prostate glands in men suspected of prostate cancer (PCa).

METHODS

We conducted a protocol-based, prospective, prebiopsy quantitative SWI of prostate glands in 50 unscreened men suspected of prostate cancer between July 2011 and May 2012. The ultrasound image of whole prostate gland was arbitrarily divided into 12 zones for sampling biopsies, as is carried out in routine clinical practice. Each region was imaged by grey scale and SWI imaging techniques. Each region was further biopsied irrespective of findings of grey scale or SWI on ultrasound. Additional biopsies were taken if SWI abnormal area was felt to be outside of these 12 zones. Quantitative assessment of SWI abnormal areas was obtained in kilopascals (kPa) from abnormal regions shown by SWI and compared with histopathology. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated for SWI (histopathology was a reference standard).

RESULTS

Fifty patients, with a mean age of 69 ± 6.2 years, were recruited into the study. Thirty-three (66%) patients were diagnosed with PCa, while an additional 4 (8%) had atypia in at least one of the 12 prostate biopsies. Thirteen (26%) patients had a benign biopsy. Data analysed per core for SWI findings showed that for patients with PSA <20 μg/L, the sensitivity and specificity of SWI for PCa detection were 0.9 and 0.88, respectively, while in patients with PSA >20 μg/L, the sensitivity and specificity were 0.93 and 0.93, respectively. In addition, PCa had significantly higher stiffness values compared to benign tissues (p <0.05), with a trend toward stiffness differences in different Gleason grades.

CONCLUSION

SWI provides quantitative assessment of the prostatic tissues and, in our preliminary observation, provides better diagnostic accuracy than grey-scale ultrasound imaging.

Is a visible (hypoechoic) lesion at biopsy an independent predictor of prostate cancer outcome?

The aim of this study was to evaluate the prognostic implications of the sonographic appearance of prostate cancers. All patients with biopsy-proven prostate cancer between January 2003 and July 2004 (and at least 5 years of follow-up) were selected retrospectively. After exclusions, 101 patients constituted our study population and were divided into isoechoic (or nonvisible) and hypoechoic (or visible) lesion. The clinical outcomes of these two groups were compared. The outcomes for the two groups were significantly different (p < 0.01). For nonvisible lesions, 37 of the 41 patients (90.2%) had no disease relapse and 2 (4.9%) had biochemical failure. For the visible lesions, 37 of the 60 (61.6%) patients were free of recurrence, 7 (11.7%) had systemic metastases and 10 (16.7%) died of complications related to prostate cancer. Our data show that patients with nonvisible prostate cancer had significantly better outcomes than patients with visible lesions during a five-year period of evaluation.

Contrast-enhanced ultrasonography with contrast-tuned imaging technology for the detection of prostate cancer: comparison with conventional ultrasonography

Study Type - Diagnostic (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? The present study was to perform contrast-tuned imaging (CnTI) technology to detect prostate cancer and compare the use of CnTI technology for the detection of prostate cancer with conventional ultrasonography. The preliminary data from our study suggested that targeted biopsy of the prostate with CnTI technology could improve the cancer detection and detect higher grade prostate cancers.

OBJECTIVES

To perform contrast-enhanced ultrasonography (CEUS) using contrast-tuned imaging (CnTI) technology to detect prostate cancer. To evaluate the detection of prostate cancer with CnTI compared with conventional grey-scale and power Doppler ultrasonography.

PATIENTS AND METHODS

In all, 150 patients referred for prostate biopsy were evaluated using transrectal grey-scale, power Doppler and CnTI ultrasonography. Biopsy was performed at 10 sites in each patient. If an abnormality was found at any of these three ultrasonography examinations, a biopsy specimen was targeted towards from the corresponding site. The performances of the three ultrasonography techniques for prostate cancer detection were compared.

RESULTS

Prostate cancer was detected at 383 sites from 73 patients. The combination of these three examinations detected more patients with prostate cancer than grey-scale (P= 0.002), power Doppler (P= 0.001) or baseline imaging (the combination of grey-scale and power Doppler; P= 0.031) alone. By biopsy site, CnTI had higher sensitivity and accuracy (73.1% and 83.7%) than grey-scale (50.9%; P < 0.001 and 78.8%; P < 0.001) or power Doppler (48.3%; P < 0.001 and 77.7%; P < 0.001), while the specificity was similar for grey-scale (88.4%), power Doppler (87.8%) and CnTI (87.3%; P > 0.05 in each case). CnTI had higher sensitivity (73.1% vs 62.9%; P < 0.001), specificity (87.3% vs 82.1%; P < 0.001) and accuracy (83.7% vs 77.2%; P < 0.001) than baseline imaging. The mean Gleason score of CnTI-positive cases was significantly higher than CnTI-negative cases (7.1 vs 6.3; P= 0.002).

CONCLUSIONS

CEUS using CnTI technology enables a visualization of the microvasculature associated with prostate cancer. CnTI technology could be used to guide biopsy and improve the detection rate of prostate cancer. CnTI technology was able to detect higher grade prostate cancers.

Value of contrast-enhanced sonography with micro flow imaging in the diagnosis of prostate cancer

BACKGROUND

To evaluate the effectiveness of contrast-enhanced sonographic micro flow imaging (MFI) in the diagnosis of prostate cancer.

METHODS

A total of 74 patients referred for prostate biopsy were prospectively evaluated with MFI. The abnormalities were categorized into four patterns: pattern 1: indistinct separation between the inner and outer gland; pattern 2: asymmetrical or focally increased enhancement in the outer gland; pattern 3: enhancement with focal defect; pattern 4: enhancement in the outer gland equal to that of the inner gland. The findings were correlated with Gleason scores.

RESULTS

Prostate cancer was detected in 264 sites in 41 patients. The sensitivity, specificity, accuracy, and positive and negative predictive values for MFI were 81.1%, 84.3%, 83.3%, 68.6%, and 91.3%, respectively. Positive predictive values for the four patterns were 46.0 (pattern 1), 53.6 (pattern 2), 94.3 (pattern 3), and 95.4 (pattern 4). Gleason scores of cancers with patterns 3 (7.09) or 4 (7.51) were significantly higher than those with patterns 1 (6.17) or 2 (6.59) (p = 0.001, p = 0.005, p < 0.001, p < 0.001).

CONCLUSIONS

Some MFI patterns had high positive predictive values and were associated with more aggressive cancers. This could be used to reduce the number of biopsy sites and detect clinically significant cancers.

Combined multiparametric MRI and targeted biopsies improve anterior prostate cancer detection, staging, and grading

OBJECTIVES

To assess the efficacy of magnetic resonance imaging (MRI) in detection of suspicious anterior prostate lesions, and its role in staging and grading of anterior prostate cancer (APC).

METHODS

Between January 2008 and August 2009, 243 patients had prostate cancer diagnosed at 12-cores posterior systematic biopsies and additional 2-cores transrectal ultrasound-guided, free-hand-targeted biopsy at any area suspicious for malignancy at prebiopsy multiparametric MRI. We conducted a retrospective study of 45 of 243 (19%) patients with an area suspicious for malignancy at MRI predominantly located in the anterior part of the gland, for which targeted biopsies were positive. Targeted vs systematic biopsy cancer detection rate and upgrading based on length of cancer in the most involved core and Gleason score were measured.

RESULTS

Of the 45 patients, 46 separate APCs were identified at MRI with positive targeted biopsies. APC was not detected by systematic biopsies in 21 (46%) cases and detected in 25 (54%) cases. For these 25 cases, median cancer length of the most involved core in targeted compared with systematic biopsies was 8 mm vs 1 mm (P <.001), respectively. Significant Gleason score upgrading was observed in 11 of 25 (44%) cases. Correlation coefficient between the cancer length on targeted biopsies and the antero-posterior diameter of the area suspicious for malignancy on MRI was r(2) = .6 (P <.001). Separate posterior cancer was diagnosed in 26 patients.

CONCLUSIONS

Targeted biopsies based on a prebiopsy MRI-detected lesion improved detection rate, volume, and grade of APC compared with currently used 12-cores systematic biopsies.

Detection of prostate cancer with three-dimensional transrectal ultrasound: correlation with biopsy results

OBJECTIVES

The aim of this study was to evaluate the role of three-dimensional transrectal ultrasound in the diagnosis of prostate cancer.

METHODS

A total of 112 patients with elevated serum prostate-specific antigen (PSA) or a positive digital rectal examination were evaluated using three-dimensional greyscale transrectal ultrasound (3D-GS TRUS) and three-dimensional power Doppler sonography (3D-PDS). Target biopsies were obtained together with 12 core systematic biopsies. Pathological results were correlated with the imaging data.

RESULTS

Cancers were detected in 269 biopsy sites from 41 patients. 229 sites of cancer were depicted by 3D-GS TRUS and 213 sites were depicted by 3D-PDS. 30 sites were missed by both 3D-GS TRUS and 3D-PDS. Abnormal prostate images depicted by 3D-GS TRUS and 3D-PDS were associated with lesions with a Gleason score of 6.9 or higher.

CONCLUSION

The detection rates of prostate cancer were significantly improved with 3D-GS TRUS and 3D-PDS on serum PSA levels >10 ng ml(-1) or 20 ng ml(-1). 3D-GS TRUS and 3D-PDS may improve the biopsy yield by determining appropriate sites for target and systematic biopsies. The abnormalities detected by 3D ultrasound were associated with moderate- and high-grade prostate cancers. However, based on the number of false-negative TRUS results, the use of systematic prostate biopsies should not be eliminated.

State-of-the-art uroradiologic imaging in the diagnosis of prostate cancer

In the diagnostic process of prostate cancer, several radiologic imaging modalities significantly contribute to the detection and localization of the disease. These range from transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) to positron emission tomography (PET). Within this review, after evaluation of the literature, we will discuss the advantages and disadvantages of these imaging modalities in clarifying the patient's clinical status as to whether he has prostate cancer or not and if so, where it is located, so that therapy appropriate to the patient's disease may be administered. TRUS, specifically with the usage of intravenous contrast agents, provides an excellent way of directing biopsy towards suspicious areas within the prostate in the general (screening) population. MRI using functional imaging techniques allows for highly accurate detection and localization, particularly in patients with prior negative ultrasound guided biopsies. A promising new development is the performance of biopsy within the magnetic resonance scanner. Subsequently, a proposal for optimal use of radiologic imaging is presented and compared with the European and American urological guidelines on prostate cancer.

Imaging in prostate cancer

Prostate cancer is the most common malignancy in men, in general. Most patients diagnosed with prostate cancer have localized disease confined to the prostate. A small percentage of patients with aggressive tumors will progress to develop local, extracapsular tumor extension and distant metastases. The aim of prostate cancer management is to identify and treat those patients with aggressive disease before they develop locally advanced or metastatic disease, and to avoid overtreating indolent tumors, which are unlikely to be life threatening. Imaging has been shown to be valuable in local staging of prostate cancer and as an aid to the management of clinically significant disease. In this article, we discuss the different established imaging modalities and emerging techniques for prostate cancer imaging in patients with clinically localized disease who may be suitable for radical treatment.

Modalities for imaging of prostate cancer

Prostate cancer is the second most common cause of cancer deaths among males in the United States. Prostate screening by digital rectal examination and prostate-specific antigen has shifted the diagnosis of prostate cancer to lower grade, organ confined disease, adding to overdetection and overtreatment of prostate cancer. The new challenge is in differentiating clinically relevant tumors from ones that may otherwise never have become evident if not for screening. The rapid evolution of imaging modalities and the synthesis of anatomic, functional, and molecular data allow for improved detection and characterization of prostate cancer. However, the appropriate use of imaging is difficult to define, as many controversial studies regarding each of the modalities and their utilities can be found in the literature. Clinical practice patterns have been slow to adopt many of these advances as a result. This review discusses the more established imaging techniques, including Ultrasonography, Magnetic Resonance Imaging, MR Spectroscopy, Computed Tomography, and Positron Emission Tomography. We also review several promising techniques on the horizon, including Dynamic Contrast-Enhanced MRI, Diffuse-Weighted Imaging, Superparamagnetic Nanoparticles, and Radionuclide Scintigraphy.

Optoacoustic imaging of the prostate: development toward image-guided biopsy

Optoacoustic (OA) tomography has demonstrated utility in identifying blood-rich malignancies in breast tissue. We describe the development and characterization of a laser OA imaging system for the prostate (LOIS-P). The system consists of a fiber-coupled Q-switched laser operating at 757 nm, a commercial 128-channel ultrasonic probe, a digital signal processor, and software that uses the filtered radial back-projection algorithm for image reconstruction. The system is used to reconstruct OA images of a blood-rich lesion induced in vivo in a canine prostate. OA images obtained in vivo are compared to images acquired using ultrasound, the current gold standard for guiding biopsy of the prostate. Although key structural features such as the urethra could be identified with both imaging techniques, a bloody lesion representing a highly vascularized tumor could only be clearly identified in OA images. The advantages and limitations of both forward and backward illumination modes are also evaluated by collecting OA images of phantoms simulating blood vessels within tissue. System resolution is estimated to be 0.2 mm in the radial direction of the acoustic array. The minimum detectable pressure signal is 1.83 Pa. Our results encourage further development toward a dual-modality OA/ultrasonic system for prostate imaging and image-guided biopsy.

A feasibility study of novel ultrasonic tissue characterization for prostate-cancer diagnosis: 2D spectrum analysis of in vivo data with histology as gold standard

This study demonstrates the feasibility of using a novel 2D spectrum ultrasonic tissue characterization (UTC) technique for prostate-cancer diagnosis. Normalized 2D spectra are computed by performing Fourier transforms along the range (beam) and the cross-range directions of the digital radio-frequency echo data, then dividing by a reference spectrum. This 2D spectrum method provides axial and lateral information of tissue microstructures, an improvement over the current 1D spectrum analysis which only provides axial information. A pilot study was conducted on four prostate-cancer patients who underwent radical prostatectomies. Cancerous and noncancerous regions of interest, identified through histology, were compared using four 2D spectral parameters: peak value and 3 dB width of the radially integrated spectral power (RISP), slope and intercept of the angularly integrated spectral power (AISP). For noncancerous and cancerous prostatic tissues, respectively, our investigation yielded 23 +/- 1 and 26 +/- 1 dB for peak value of RISP, 7.8 +/- 0.5 degrees and 7.6 +/- 0.6 degrees for 3 dB of RISP, -2.1 +/- 0.2 and -2.7 +/- 0.4 dB/MHz for slope of AISP, and 92 +/- 5 and 112 +/- 6 dB for intercept of AISP. Preliminary results indicated that 2D spectral UTC has the potential for identifying tumor-bearing regions within the prostate gland.

Classification of focal prostatic lesions on transrectal ultrasound (TRUS) and the accuracy of TRUS to diagnose prostate cancer

Objective

To improve the diagnostic efficacy of transrectal ultrasound (TRUS)-guided targeted prostatic biopsies, we have suggested the use of a new scoring system for the prediction of malignancies regarding the characteristics of focal suspicious lesions as depicted on TRUS.

Materials and Methods

A total of 350 consecutive patients with or without prostate cancer who underwent targeted biopsies for 358 lesions were included in the study. The data obtained from participants were randomized into two groups; the training set (n = 240) and the test set (n = 118). The characteristics of focal suspicious lesions were evaluated for the training set and the correlation between TRUS findings and the presence of a malignancy was analyzed. Multiple logistic regression analysis was used to identify variables capable of predicting prostatic cancer. A scoring system that used a 5-point scale for better malignancy prediction was determined from the training set. Positive predictive values for malignancy prediction and the diagnostic accuracy of the scored components with the use of receiver operating characteristic curve analysis were evaluated by test set analyses.

Results

Subsequent multiple logistic regression analysis determined that shape, margin irregularity, and vascularity were factors significantly and independently associated with the presence of a malignancy. Based on the use of the scoring system for malignancy prediction derived from the significant TRUS findings and the interactions of characteristics, a positive predictive value of 80% was achieved for a score of 4 when applied to the test set. The area under the receiver operating characteristic curve (AUC) for the overall lesion score was 0.81.

Conclusion

We have demonstrated that a scoring system for malignancy prediction developed for the characteristics of focal suspicious lesions as depicted on TRUS can help predict the outcome of TRUS-guided biopsies.

Transrectal ultrasound in detecting prostate cancer compared with serum total prostate-specific antigen levels

We carried out a retrospective study to review the efficiency of grey-scale transrectal ultrasonography (TRUS) in detecting prostate cancer compared with the data in recent published work, including alternative imaging methods of the prostate gland. Our study group consisted of 830 patients who underwent TRUS-guided biopsy of the prostate between May 2000 and June 2004. The relation between abnormal TRUS findings and serum total prostate-specific antigen (tPSA) levels was evaluated in patients with prostate cancer who were divided into three different groups according to serum tPSA levels. Group I included patients with tPSA levels of 4-9.9 ng/mL, group II included tPSA levels of 10-19.9 ng/mL and group III included patients with tPSA levels of 20 ng/mL or more. In general, TRUS detected 185 (64%) of 291 cancers with a specificity of 89%, a PPV of 76% and an accuracy of 80%. TRUS findings enabled the correct identification of 22 (56%) of the 39 cancers in group I, 28 (30%) of the 93 cancers in group II and 135 (85%) of the 159 cancers in group III. In conclusion, TRUS alone has a limited potential to identify prostate cancer, especially in patients with tPSA levels lower than 20 ng/mL. Therefore, increased numbers of systematically placed biopsy cores must be taken or alternative imaging methods are required to direct TRUS-guided biopsy for improving prostate cancer detection.

Imaging in Oncology from The University of Texas M. D. Anderson Cancer Center: Diagnosis, Staging, and Surveillance of Prostate Cancer

OBJECTIVE

The purpose of this article is to discuss the epidemiology, risk factors, and presentation of prostate cancer. After reviewing the prostate anatomy, the article will show how imaging plays an important role in establishing the diagnosis, staging, and monitoring the therapeutic response in prostate cancer, with a focus on adenocarcinomas.

CONCLUSION

Imaging studies, in the appropriate laboratory and clinical context, contribute essential information that enhances the capacity to provide individualized risk stratification, a suitable treatment strategy, and monitoring for the patient with prostate cancer.

Transrectal high-intensity focused ultrasound ablation of prostate cancer: Effective treatment requiring accurate imaging

Transrectal HIFU ablation has become a reasonable option for the treatment of localized prostate cancer in non-surgical patients, with 5-year disease-free survival similar to that of radiation therapy. It is also a promising salvage therapy of local recurrence after radiation therapy. These favourable results are partly due to recent improvements in prostate cancer imaging. However, further improvements are needed in patient selection, pre-operative localization of the tumor foci, assessment of the volume treated and early detection of recurrence. A better knowledge of the factors influencing the HIFU-induced tissue destruction and a better pre-operative assessment of them by imaging techniques should improve treatment outcome. Whereas prostate HIFU ablation is currently performed under transrectal ultrasound guidance, MR guidance with real-time operative monitoring of temperature will be available in the near future. If this technique will give better targeting and more uniform tissue destruction, its cost-effectiveness will have to be carefully evaluated. Finally, a recently reported synergistic effect between HIFU ablation and chemotherapy opens possibilities for treatment in high-risk or clinically advanced tumors.

Contrast-enhanced versus systematic transrectal ultrasound-guided prostate cancer detection: an overview of techniques and a systematic review

An overview is given of the current conventional and contrast-specific transrectal ultrasound (TRUS) techniques for prostate imaging that may be used for guiding biopsy. Subsequently, a systematic literature search resulted in inclusion of four studies that directly compared systematic and contrast-enhanced-targeted TRUS-guided biopsy of the prostate. All four studies revealed that contrast-enhanced-targeted TRUS-guided biopsy significantly improved the positive biopsy core rate. In the largest study, the mean Gleason score of the contrast-enhanced-targeted TRUS-guided biopsies was significantly higher than that of the systematic biopsies. Future randomized clinical trials, preferably in a non-academic multi-institutional set-up, will have to be performed to confirm the value of contrast-enhanced-targeted TRUS-guided biopsy in regular clinical practice.

Bildgebende Verfahren bei der Diagnose des Prostatakarzinoms

Prostate cancer is one of the most frequent malignant diseases in men. Despite constant progress achieved in imaging procedures, prostate biopsy is the gold standard for diagnosing prostate cancer. For the assessment of lymph node status, only staging lymphadenectomy provides valid information. The aim of this work is to analyze the imaging procedures available in Germany and their value in primary and lymph node staging as well as biochemical recurrence.

Transrectal contrast enhanced ultrasound for diagnosis of prostate cancer

The diagnosis of prostate cancer is based on histology. Prostate biopsies are obtained based on the triad of prostate specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasound. Because prostate biopsies still have a large percentage of negative outcomes, patient selection and biopsy direction need improvement. This paper describes the recent improvements in prostate cancer imaging, especially contrast-enhanced transrectal ultrasound.

Imaging prostate cancer: a multidisciplinary perspective

The major goal for prostate cancer imaging in the next decade is more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information. No consensus exists regarding the use of imaging for evaluating primary prostate cancers. Ultrasonography is mainly used for biopsy guidance and brachytherapy seed placement. Endorectal magnetic resonance (MR) imaging is helpful for evaluating local tumor extent, and MR spectroscopic imaging can improve this evaluation while providing information about tumor aggressiveness. MR imaging with superparamagnetic nanoparticles has high sensitivity and specificity in depicting lymph node metastases, but guidelines have not yet been developed for its use, which remains restricted to the research setting. Computed tomography (CT) is reserved for the evaluation of advanced disease. The use of combined positron emission tomography/CT is limited in the assessment of primary disease but is gaining acceptance in prostate cancer treatment follow-up. Evidence-based guidelines for the use of imaging in assessing the risk of distant spread of prostate cancer are available. Radionuclide bone scanning and CT supplement clinical and biochemical evaluation (prostate-specific antigen [PSA], prostatic acid phosphate) for suspected metastasis to bones and lymph nodes. Guidelines for the use of bone scanning (in patients with PSA level > 10 ng/mL) and CT (in patients with PSA level > 20 ng/mL) have been published and are in clinical use. Nevertheless, changes in practice patterns have been slow. This review presents a multidisciplinary perspective on the optimal role of modern imaging in prostate cancer detection, staging, treatment planning, and follow-up.

Detection of clinical unilateral T3a prostate cancer ? by digital rectal examination or transrectal ultrasonography?

OBJECTIVE

To assess, in a retrospective study, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of digital rectal examination (DRE), transrectal ultrasonography (TRUS) and the combination of both in unilateral clinical T3a (cT3a) prostate cancer.

PATIENTS AND METHODS

The long-term outcome of surgical treatment for locally advanced prostate cancer is very good and surpasses that for radiotherapy outcomes, so it is anticipated that surgical management for cT3a disease will become more important, but staging methods for cT3a disease are not well studied. Between 1990 and 2004, 2240 patients had a radical prostatectomy at our institution; 267 were diagnosed as having clinical cT3a prostate cancer either by DRE or TRUS. The final histopathology was compared with the findings of DRE and TRUS. The sensitivity, specificity, PPV and NPV for DRE, TRUS and the combination of both were calculated.

RESULTS

The sensitivity, specificity, PPV and NPV by DRE only was 90.9%, 15.8%, 47.2% and 67.7%, by TRUS only was 80.2%, 25.3%, 47.1% and 60.7%, and by both DRE and TRUS was 71.1%, 41.1%, 50.0% and 63.2%. Although the sensitivity was lower in the combined group, it had the highest specificity (41.1%) and PPV (50.0%). The combination of DRE and TRUS can detect T3a prostate cancer more accurately than either method alone.

CONCLUSION

Until data on staging methods like magnetic resonance imaging become available, the combination of DRE and TRUS is advisable in selecting cT3a patients for primary radical prostatectomy.

Evaluation of Color Doppler in Guiding Prostate Biopsy after HIFU Ablation

OBJECTIVE

Transrectal ultrasound cannot accurately depict early cancer recurrences after prostate high-intensity focused ultrasound (HIFU) ablation. We evaluated transrectal color Doppler (CD) in guiding post-HIFU prostate biopsy.

METHODS

Prostate CD-guided sextant biopsies were obtained in 82 patients who had undergone prostate HIFU ablation for cancer, 24 of whom had hormone therapy before the treatment. At the time of biopsy, a subjective CD score was given to all biopsy sites (0=no flow; 1=minimal flow; 2=suspicious flow pattern). CD findings were compared with biopsy results.

RESULTS

CD was a significant predictor of biopsy findings, according to univariate and multivariate site-by-site analysis. However, only 36 of 94 sites with residual cancer had positive CD findings, and thus, negative CD findings should not preclude random biopsy. There was a significant interaction between CD diagnostic capability and a history of hormone therapy before HIFU treatment. CD was a significant and independent predictor of biopsy findings in patients who had not received hormone therapy (odds ratio: 4.4; 95%CI: 2.5-7.9; p<0.0001), but not in those who had (odds ratio: 1.3; 95%CI: 0.5-3.4; p>0.5).

CONCLUSION

Biopsy taken in CD-positive sites were 4.4 times more likely to contain cancer in patients who did not receive hormone therapy. CD could not reliably depict cancer recurrence in patients with history of hormone therapy.