MR-Techniken zur nicht-invasiven Diagnostik des Prostatakarzinoms

The diagnosis of prostate cancer is suggested on the basis of an elevated PSA level, abnormal digital exam, and abnormal transrectal ultrasound. US-guided biopsy is used to confirm the diagnosis, but up to 30% of prostate cancer may be missed with this approach. Meanwhile MR imaging and proton MR spectroscopy have emerged as the most sensitive additional tools for the noninvasive evaluation of prostate cancer. This article reviews the clinical indications for MRI of the prostate and summarizes new techniques such as high field strength (3 tesla) and dynamic contrast-enhanced MRI.     

前列腺癌的MRI诊断价值及其误诊原因分析

目的：评价MRI对前列腺癌的定性诊断价值，分析前列腺癌MRI的误诊原因。方法：采用MRI技术对80例前列腺疾病患者进行检查，并经系统穿刺活检病理检查证实。结果：80例患者中，前列腺癌51例，前列腺良性病变29例。MRI对前列腺癌的定性诊断准确率为86．3％，敏感度90．2％，特异度79．3％，阳性预测值88．5％，阴性预测值82．1％。前列腺癌误诊6例，慢性前列腺炎(4例)、炎性肉芽肿(1例)、良性增生(1例)表现均与前列腺癌相似，鉴别困难。漏诊的5例前列腺癌中，1例信号强度和正常外周带信号相似，无法显示；2例受活检后出血信号干扰，无法显示肿瘤病灶；2例异常信号弥漫分布，误为慢性炎症。结论：MRI可用于前列腺癌的定性诊断，其特异性有待提高。     

Bedeutung der Magnetresonanztomographie (MRT) für Nachweis und Ausschluss des Prostatakarzinoms

This review illustrates the relevance of magnetic resonance imaging (MRI) for the detection or exclusion of prostate cancer. The functional MR methods dynamic contrast-enhanced MRI (DCE-MRI), MR spectroscopy, and diffusion-weighted imaging (DWI) helped in recent years to establish MRI as the imaging method of choice for prostate cancer. Indications for MRI of the prostate regarding recent guidelines and new concepts of cancer therapy are introduced.     

多参数磁共振成像技术在前列腺癌诊断中的应用价值

目的:研究多参数磁共振成像技术(MP-MRI)诊断前列腺癌(PCa)的应用价值。方法:分析62例PCa临床疑似患者的T2加权成像、弥散加权成像、体素内无规则运动核磁成像及动态对比增强成像等MRI数据。结果:62例患者中,MP-MRI诊断PCa的诊断符合率为87.1%,灵敏度为90.5%,特异度为85.4%。结论:MP-MRI在PCa的临床诊断中具有重要价值。     

Sinnvolle bildgebende Diagnostik des lokal fortgeschrittenen Prostatakarzinoms

Prostate cancer is one of the principal medical problems facing the male population in developed countries with an increasing need for sophisticated imaging techniques and risk-adapted treatment options. This article presents an overview of the current imaging procedures in the diagnosis of locally advanced prostate cancer. Apart from conventional gray-scale transrectal ultrasound (TRUS) as the most frequently used primary imaging modality we describe computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). CT and MRI not only allow assessment of prostate anatomy but also a specific evaluation of the pelvic region. Color-coded and contrast-enhanced ultrasound, real-time elastography, dynamic contrast enhancement in MR imaging, diffusion imaging, and MR spectroscopy may lead to a clinically relevant improvement in the diagnosis of prostate cancer. While bone scintigraphy with (99m)Tc-bisphosphonates is still the method of choice in the evaluation of bone metastasis, whole-body MRI and PET using (18)F-NaF, (18)F-FDG, (11)C-choline, (11)C-acetate, and (18)F-choline as tracers achieve higher sensitivities.     

Prostate cancer detection by prebiopsy 3.0‐Tesla magnetic resonance imaging

Objectives: The diagnostic value of 3.0‐Tesla magnetic resonance imaging (MRI) for prostate cancer remains to be determined. The aim of the present study was to assess the features of prostate cancer detectable by prebiopsy 3.0‐Tesla MRI. Methods: From January 2007 through to December 2008, 116 patients who were examined by prebiopsy 3.0‐Tesla MRI underwent radical prostatectomy for localized prostate cancer. Prostate specimens were examined to see whether the largest cancer area was the same as the area indicated on the MRI. Univariate and multivariate logistic regression analyses were conducted to identify variables predictive of agreement between MRI and histopathological findings. Results: Sixty‐six (56.9%) patients were suspected of having prostate cancer on the basis of MRI findings. In 49 of these patients (74.2%), it was considered that there was agreement between the abnormal area on the MRI and the index tumor. Univariate analysis revealed that there were significant differences in abnormal digital rectal examination, capsular penetration, the diameter of the index tumor of the radical prostatectomy specimen, and the Gleason scores of the biopsy and radical prostatectomy specimens. Multivariate analysis revealed that the Gleason score of the radical prostatectomy specimen was associated with the accurate detection of the prostate cancer by MRI (P = 0.0177). Conclusions: In conclusion, 3.0‐Tesla MRI tends to accurately diagnose prostate cancer with high tumor burden and aggressiveness. Multimodal examination (T2‐weighted imaging, dynamic contrast‐enhanced imaging, and diffusion‐weighted imaging) is recommended for the diagnosis of prostate cancer using 3.0‐Tesla MRI.     

The value of magnetic resonance imaging and ultrasonography (MRI/US)‐fusion biopsy platforms in prostate cancer detection: a systematic review

Despite limitations considering the presence, staging and aggressiveness of prostate cancer, ultrasonography (US)‐guided systematic biopsies (SBs) are still the ‘gold standard’ for the diagnosis of prostate cancer. Recently, promising results have been published for targeted prostate biopsies (TBs) using magnetic resonance imaging (MRI) and ultrasonography (MRI/US)‐fusion platforms. Different platforms are USA Food and Drug Administration registered and have, mostly subjective, strengths and weaknesses. To our knowledge, no systematic review exists that objectively compares prostate cancer detection rates between the different platforms available. To assess the value of the different MRI/US‐fusion platforms in prostate cancer detection, we compared platform‐guided TB with SB, and other ways of MRI TB (cognitive fusion or in‐bore MR fusion). We performed a systematic review of well‐designed prospective randomised and non‐randomised trials in the English language published between 1 January 2004 and 17 February 2015, using PubMed, Embase and Cochrane Library databases. Search terms included: ‘prostate cancer’, ‘MR/ultrasound(US) fusion’ and ‘targeted biopsies’. Extraction of articles was performed by two authors (M.G. and A.A.) and were evaluated by the other authors. Randomised and non‐randomised prospective clinical trials comparing TB using MRI/US‐fusion platforms and SB, or other ways of TB (cognitive fusion or MR in‐bore fusion) were included. In all, 11 of 1865 studies met the inclusion criteria, involving seven different fusion platforms and 2626 patients: 1119 biopsy naïve, 1433 with prior negative biopsy, 50 not mentioned (either biopsy naïve or with prior negative biopsy) and 24 on active surveillance (who were disregarded). The Quality Assessment of Diagnostic Accuracy Studies (QUADAS‐2) tool was used to assess the quality of included articles. No clear advantage of MRI/US fusion‐guided TBs was seen for cancer detection rates (CDRs) of all prostate cancers. However, MRI/US fusion‐guided TBs tended to give higher CDRs for clinically significant prostate cancers in our analysis. Important limitations of the present systematic review include: the limited number of included studies, lack of a general definition of ‘clinically significant’ prostate cancer, the heterogeneous study population, and a reference test with low sensitivity and specificity. Today, a limited number of prospective studies have reported the CDRs of fusion platforms. Although MRI/US‐fusion TB has proved its value in men with prior negative biopsies, general use of this technique in diagnosing prostate cancer should only be performed after critical consideration. Before bringing MRI/US fusion‐guided TB in to general practice, there is a need for more prospective studies on prostate cancer diagnosis.     

磁共振间质淋巴造影诊断前列腺癌盆腔淋巴结转移的安全性和可行性研究

目的 评估欧乃影介导的磁共振间质淋巴造影诊断前列腺癌盆腔淋巴结转移的可行性和安全性。方法 对30例确诊为前列腺癌的患者于双侧腹股沟及阴囊根部皮下真皮层内注射欧乃影,通过三维增强磁共振淋巴造影增强扫描,采用兴趣区法测量造影后各组淋巴结的信号强度,绘制不同延迟时间引流区域淋巴结信号强度的时间-信号强度曲线,定性和定量分析以评估淋巴管及淋巴结增强造影效果。结果 皮下注射欧乃影后,欧乃影迅速吸收进入淋巴系统,引流区域各组淋巴结显示清晰。皮下注射对比剂9min后腹股沟淋巴结信号强度达到峰值,而髂内、外淋巴结则于注射后11min达到最大信号强度;各组淋巴结间的峰值信号强度有明显差异。常规MRI扫描辨认淋巴结19枚,欧乃影静脉注射增强扫描辨认淋巴结21枚,磁共振间质淋巴造影共辨认淋巴结162枚。常规扫描辨认可疑转移淋巴结6枚,欧乃影静脉注射增强扫描辨认可疑转移淋巴结6枚,磁共振间质淋巴造影辨认可疑转移淋巴结26枚。常规和增强磁共振不能检出的〈1.0cm的转移淋巴结可通过磁共振间质淋巴造影检出。结论 经腹股沟及阴囊根部皮下注射欧乃影磁共振间质淋巴造影术诊断前列腺癌盆腔淋巴结转移安全、可行,该注射途径对盆腔淋巴结的显影更加全面。     

Magnetic resonance spectroscopy-guided transperineal prostate biopsy and brachytherapy for recurrent prostate cancer

Brachytherapy targeted to the peripheral zone with magnetic resonance imaging (MRI) guidance is a prostate cancer treatment option with potentially fewer complications than other treatments. Follow-up MRI when failure is suspected is, however, difficult because of radiation-induced changes. Furthermore, MR spectroscopy (MRS) is compromised by susceptibility artifacts from radioactive seeds in the peripheral zone. We report a case in which combined MRI/MRS was useful for the detection of prostate cancer in the transitional zone in patients previously treated with MR-guided brachytherapy. We propose that MRI/MRS can help detect recurrent prostate cancer, guide prostate biopsy, and help manage salvage treatment decisions.     

The role of magnetic resonance imaging in targeting prostate cancer in patients with previous negative biopsies and elevated prostate‐specific antigen levels

In the past 20 years, magnetic resonance imaging (MRI) has developed rapidly, along with the management of localized prostate cancer. We summarize current data on the efficacy of MRI for targeting cancer, compared with biopsies, in patients with previous negative prostate biopsies and persistently elevated prostate‐specific antigen (PSA) levels. The key clinical question is how many men benefit by having had prostate cancer detected purely because of the MRI‐targeted, as opposed to standard scheme, biopsies. We reviewed all available databases for prospective studies in patients having MRI and prostate biopsy with previous negative biopsies and persistently elevated PSA levels. Six studies fulfilled the selection criteria, with 215 patients in all; in these studies, the cancer‐detection rate at repeat biopsy was 21–40%. For MRI or combined MRI/MR spectroscopy, the overall sensitivity for predicting positive biopsies was 57–100%, the specificity 44–96% and the accuracy 67–85%. In five studies, specific MRI‐targeted biopsies and standard cores were taken, with a significant proportion (34/63, 54%) having cancer detected purely because of the MRI‐targeted cores. The value of endorectal MRI and MR spectroscopy in patients with elevated PSA levels and previous negative biopsies to target peripheral zone tumours appears to be significant. Although more data obtained with current technologies are needed, published results to data are encouraging. A comparison study and cost‐benefit analysis of MRI‐targeted vs saturation biopsy in this group of patients would also be ideal, to delineate any advantages.     

Prostate MRI spectroscopy

MRI spectroscopy is a non invasive method for detecting active metabolites used as markers. Chorine and citrate are used for analyzing prostate cancer. MRI spectroscopy combines morphologic imaging and metabolic cartography. This combination allows a new approach for the diagnosis of prostate cancer in patients with negative biopsy and high Levels of PSA. With MRI spectroscopy the Local staging of prostate cancer has a better accuracy than with MRI alone. It can also be used for the diagnosis of residual disease and recurrence in patients treated with conservative therapy.     

The utility of magnetic resonance imaging and spectroscopy for predicting insignificant prostate cancer: an initial analysis

OBJECTIVE: To design new models that combine clinical variables and biopsy data with magnetic resonance imaging (MRI) and MR spectroscopic imaging (MRSI) data, and assess their value in predicting the probability of insignificant prostate cancer. PATIENTS AND METHODS: In all, 220 patients (cT stage T1c or T2a, prostate-specific antigen level <20 ng/mL, biopsy Gleason score 6) had MRI/MRSI before surgery and met the inclusion criteria for the study. The probability of insignificant cancer was recorded retrospectively and separately for MRI and combined MRI/MRSI on a 0-3 scale (0, definitely insignificant; - 3, definitely significant). Insignificant cancer was defined from surgical pathology as organ-confined cancer of 相似文献   

Magnetic resonance imaging in the evaluation of prostate cancer

Summary Advantages of magnetic resonance imaging (MRI) in the study of prostatic disease include a precise anatomical display in multiple planes, superb contrast resolution, and differential physicochemical characteristics that are obtained without known toxicity. In practice, however, MRI has not been shown to differentiate consistently between normal and abnormal prostatic tissue. Although normal prostatic and periprostatic anatomy is clearly defined in T₁-weighted images, controversy persists as to the precise differential characteristics of inflammatory and neoplastic disease within the prostate. Thus, MRI is not presently adequate for prostate cancer screening. MRI has been shown to be superior to computerized axial tomography (CAT) for pelvic staging of prostate cancer; however, comparative studies involving other modalities with precise histologic confirmation are limited and the improvement reported is modest. There is some evidence that MRI may be helpful in the detection of prostate cancer metastatic to bone, but, again, information is limited. Substantial advances in MRI techniques such as optimal pulse sequencing, surface coils, and, possibly, paramagnetic contrast agents will be required to secure a role for MRI in prostate cancer evaluation.     

Staging and tissue characterization of prostate carcinoma: role of endorectal MR imaging and MR spectroscopy

The role of magnetic resonance (MR) imaging and MR spectroscopy with an endorectal coil in tissue characterization and local staging was reviewed. Endorectal coil (ERC) MR imaging demonstrated the detailed zonal anatomy of the normal prostate. The sensitivity and specificity of staging prostate cancer for ERC MR imaging was superior to both conventional MR imaging and transrectal ultrasound. ERC MR imaging is the most accurate noninvasive method of staging prostate cancer. However, the accuracy of the diagnosis made by inexperienced radiologists was significantly inferior to that made by experienced radiologists. Endorectal MRI failed to differentiate benign from malignant lesions in some patients demonstrating low signal intensity on T2-weighted imaging in the peripheral zone. MR spectroscopy may provide additional information on tissue characterization, monitoring after treatment and staging.     

Endorectal magnetic resonance imaging and magnetic resonance spectroscopy to monitor the prostate for residual disease or local cancer recurrence after transrectal high-intensity focused ultrasound

OBJECTIVE

To assess the role of magnetic resonance imaging (MRI) for evaluating changes in the prostate after transrectal high‐intensity focused ultrasound (HIFU) for treating prostate cancer, correlating the findings with histology to assess its possible role in predicting the outcome, evaluating residual cancer or local recurrence of disease.

PATIENTS AND METHODS

Ten patients with prostate cancer were assessed with MR and MR spectroscopy (MRS) before and at 1, 4 and 12 months after HIFU, assessing the glandular volume and MRI and MRS data after HIFU. These data were correlated with the prostate‐specific antigen (PSA) levels at each examination (suspicious for residual cancer if >0.5 ng/mL) and with histological findings of prostate biopsy sampling at 6–8 months (random or targeted at suspicious MR areas).

RESULTS

Variations in volume during the follow‐up were not associated with treatment outcome. MRI was suspicious for residual cancer in one patient at 1 month and in another two at 4 months; in all three patients (one with a PSA level of <0.5 ng/mL) targeted biopsies were positive for cancer. MRI was negative in seven patients; in six of these (one with a PSA level of >0.5 ng/mL) random biopsies were negative, and in one the random biopsies were positive for residual cancer. At 4 months there was a statistically significant difference (P = 0.015) between patients responsive to treatment and those with persistent disease, by combining negative MRI with a PSA level of <0.5 ng/mL; MRS data were suitable for analysis only in three patients with partial necrosis.

CONCLUSION

Our preliminary data support the role of MRI in association with PSA levels as a useful and accurate tool in the follow‐up of patients treated with HIFU for prostate cancer. However, considering the economic issue, it should not be used routinely and should be limited to detecting residual cancer (in patients with a PSA level of >0.5 ng/mL) with the main purpose of improving the detection rate of transrectal ultrasonography (TRUS)‐guided prostate biopsy. MRS data had no additional value over MRI. Further evaluation is needed to compare the use of contrast media and other techniques (e.g. colour Doppler TRUS) in detecting residual or local recurrent cancer.     

Advances in magnetic resonance imaging: how they are changing the management of prostate cancer

Context

Although magnetic resonance imaging (MRI) is emerging as the most commonly used imaging modality for prostate cancer (PCa) detection, treatment planning, and follow-up, its acceptance has not been uniform. Recently, great interest has been shown in multiparametric MRI, which combines anatomic T2-weighted (T2W) imaging with MR spectroscopic imaging (MRSI), dynamic contrast-enhanced MRI (DCE-MRI), and diffusion-weighted imaging (DWI).

Objective

The aim of this article is to review the current roles of these MR techniques in different aspects of PCa management: initial diagnosis, biopsy strategies, planning of radical prostatectomy (RP) and external radiation therapy (RT), and implementation of alternative focal therapies.

Evidence acquisition

The authors searched the Medline and Cochrane Library databases (primary fields: prostatic neoplasm, magnetic resonance). The search was performed without language restriction from January 2008 to November 2010.

Evidence synthesis

Initial diagnosis: The data suggest that the combination of T2W MRI and DWI or MRSI with DCE-MRI has the potential to guide biopsy to the most aggressive cancer foci in patients with previously negative biopsies, increasing the accuracy of the procedure. Transrectal MR-guided prostate biopsy can improve PCa detection, but its availability is still limited and the examination time is rather long. Planning of RP: It appears that adding MRSI, DWI, and/or DCE-MRI to T2W MRI can facilitate better preoperative characterization of cancer with regard to location, size, and relationship to prostatic and extraprostatic structures, and it may also facilitate early detection of local recurrence. Thus, use of these MR techniques may improve surgical, oncologic, and functional management. Planning of external RT and focal therapies: MR techniques have similar potential in these areas, but the published data remain very limited.

Conclusions

MRI technology is continuously evolving, and more extensive use of MRI technology in clinical trials and practice will help to improve PCa diagnosis and treatment planning.     

Local staging with magnetic resonance imaging after neoadjuvant hormonal therapy for prostate cancer]

We retrospectively studied the staging accuracy of magnetic resonance (MR) imaging after neoadjuvant hormonal therapy (NAH) for 21 localized prostate cancers. MR imaging was performed using a 1.5-Tesla magnetic resonance system with a pelvic phased array coil. T2-weighted MR images were obtained on axial and coronal planes, and T1-weighted MR images using the dynamic technique with Gd-DTPA bolus enhancement were obtained in axial planes for each patient. On T2-weighted imaging, the signal intensity of the normal tissue in the peripheral zone became lower after NAH. Therefore, it was more difficult to detect residual malignant lesions in many cases than before NAH. The accuracy of T staging for prostate cancer after NAH in MRI was 71%. The accuracy, sensitivity, and specificity of the extracapsular invasion was 76%, 0% and 94%, respectively, and those of the seminal vesicular invasion 85%, 0% and 100%, respectively. While 2 of the 4 patients judged as downstaged cases in MRI showed corresponding pathological findings, 5 of the 21 cases (23.8%) were underdiagnosed. Local staging with only MRI for prostate cancer after NAH seems to have limits in applicability.     

MRI 3D-LAVA动态增强联合FRFSE序列诊断早期前列腺癌的效能

目的探讨核磁共振成像（MRI）三维容积内插快速扰相梯度回波序列（3D-LAVA）屏气检查动态增强联合快速翻转快速自旋回波序列（FRFSE）对早期前列腺癌的诊断效能。 方法对我院2013年6月至2019年6月210例可疑早期前列腺癌的临床资料进行回顾，均实施MRI 3D-LAVA动态增强、FRFSE序列扫描。总结两种扫描序列的检查结果，分析不同方法诊断早期前列腺癌的效能；另统计多参数磁共振（mpMRI）的诊断结果，绘制受试者工作特征曲线（ROC）评价不同方法诊断早期前列腺癌的效能。 结果早期前列腺癌的构成比为38.10%；早期前列腺癌（+）患者峰值和强化率均高于前列腺癌（-）受检者，且早期前列腺癌（+）患者峰值时间短于后者，强化幅度小于后者，差异均有统计学意义（P<0.05）；MRI 3D-LAVA动态增强联合FRFSE序列诊断早期前列腺癌的灵敏度与MRI 3D-LAVA动态增强、FRFSE序列单独诊断相近，特异度、准确度和曲线下面积（AUC）均高于单独诊断；MRI 3D-LAVA动态增强联合FRFSE序列诊断早期前列腺癌的灵敏度、特异度、准确度均与mpMRI相当，且二者AUC对比差异无统计学意义（P>0.05）。 结论在早期前列腺癌诊断中MRI 3D-LAVA动态增强、FRFSE序列扫描联合检查的效能理想，与病理结果的一致性良好，和mpMRI诊断早期前列腺癌的效能相近。     

Diagnostic strategies and the incidence of prostate cancer： reasons for the low reported incidence of prostate cancer in China

We have analysed the reasons for the low reported incidence of prostate cancer in China and argue for early diagnosis and treatment of this disease. According to the 2002 database of the International Agency for Research on Cancer （IARC）, the age-standardized incidence of prostate cancer in China is 1.6/105 person years （PY）, with a mortality rate of 1.0/105 PY and mortality-to-incidence rate ratio （MR/IR） = 0.63. The MR/IR ratio of prostate cancer in China was found to be higher than the average in Asia （MR/IR = 0.57） and much higher than that in North America （MR/IR = 0.13）. These data indicate that in China most prostate cancers were in the advanced stages at the time of diagnosis, and that patients had a short survival time thereafter. In 2004, Stamey et al. reported a retrospective American study of prostate cancer for the years 1983-2003. It was shown that most cases of prostate cancer detected by prostate-specific antigen （PSA） screening were in the advanced stage at the start of this 20-year period. These early follow-up data are quite similar to the results obtained from mass PSA screening of elderly men in Changchun, China. However, after the American programmes for early diagnosis and treatment of prostate cancer were accepted, tumours were diagnosed at earlier stages. On the basis of these findings, mass screening should be performed in the whole of China using serum PSA to facilitate early diagnosis and treatment of prostate cancer.     

The role of colour Doppler ultrasonography in detecting prostate cancer

OBJECTIVE: To determine the usefulness of colour Doppler ultrasonography (CDUS) in detecting prostate cancer, by comparing CDUS with grey-scale transrectal ultrasonography (TRUS) and magnetic resonance imaging (MRI). PATIENTS AND METHODS: In all, 278 patients who underwent prostate biopsies because of an abnormal digital rectal examination, elevated prostate specific antigen levels, and/or abnormal TRUS between May 1998 and November 1999 were evaluated. The diagnostic accuracies of TRUS, CDUS, MRI and combinations of these imaging techniques in detecting prostate cancer were compared, based on the biopsy results. RESULTS: Carcinoma was detected in 233 of 1696 specimens, and 87 patients were diagnosed with prostate cancer. For each detected cancer site, the sensitivity of CDUS was lower than those of other imaging techniques, but CDUS had high a specificity and positive predictive value. The combination of grey-scale TRUS and CDUS or MRI improved the sensitivity and negative predictive value. The specificity and positive predictive value of the combination of grey-scale TRUS and MRI were less than those for grey-scale TRUS alone, while those for the combination of grey-scale TRUS and CDUS were higher than those for grey-scale TRUS alone. Five tumours were isoechoic but seen as hypervascular lesions with CDUS. CONCLUSION: CDUS provides information useful for detecting prostate cancer when used in combination with grey-scale TRUS, and should be included in the routine examination for prostate cancer.