Local staging of prostate cancer using magnetic resonance imaging: a meta-analysis

Our objective was to determine the influence of patient-, study design-, and imaging protocol characteristics on staging performance of MR imaging in prostate cancer. In an electronic literature search and review of bibliographies (January 1984 to May 2000) the articles selected included data on sensitivity and specificity for local staging. Subgroup analyses examined the influence of age, prostate specific antigen, tumor grade, hormonal pre-treatment, stage distribution, publication year, department of origin, verification bias, time between biopsy and MR imaging; consensus reading, study design, consecutive patients, sample size, histology preparation, imaging planes, fast spin echo, fat suppression, endorectal coil, field strength, resolution, glucagon, contrast agents, MR spectroscopy, and dynamic contrast-enhanced MRI. Seventy-one articles and five abstracts were included, yielding 146 studies. Missing values were highly prevalent for patient characteristics and study design. Publication year, sample size, histologic gold standard, number of imaging planes, turbo spin echo, endorectal coil, and contrast agents influenced staging performance ( p=0.05). Due to poor reporting it was not possible to fully explain the heterogeneity of performance presented in the literature. Our results suggest that turbo spin echo, endorectal coil, and multiple imaging planes improve staging performance. Studies with small sample sizes may result in higher staging performance.     

Comparison of the digital rectal examination,endorectal ultrasound,and body coil magnetic resonance imaging in the staging of adenocarcinoma of the prostate

A series of 25 patients with biopsy proven adenocarcinoma of the prostate underwent preoperative staging evaluation with a digital rectal examination, endorectal ultrasound, and body coil magnetic resonance imaging (MRI) before their radical retropubic prostatectomy. The sensitivity and specificity of the digital rectal examination for the detection of extracapsular disease were 17 and 100%, respectively. The sensitivity and specificity of endorectal ultrasound for the detection of extracapsular disease were 35 and 89%, respectively. The sensitivity and specificity of body coil MRI for the detection of extracapsular disease by adenocarcinoma of the prostate were 47 and 63%, respectively. Microscopic disease of the capsule and seminal vesicles was the principle reason for understaging by both imaging modalities. This small series suggests that both imaging modalities are marginally more sensitive, albeit less specific, for extracapsular disease of the prostate than the digital rectal examination, with ultrasound having a slight edge in specificity and MRI having a slight edge in sensitivity.     

Comparison of the digital rectal examination, endorectal ultrasound, and body coil magnetic resonance imaging in the staging of adenocarcinoma of the prostate

A series of 25 patients with biopsy proven adenocarcinoma of the prostate underwent preoperative staging evaluation with a digital rectal examination, endorectal ultrasound, and body coil magnetic resonance imaging (MRI) before their radical retropubic prostatectomy. The sensitivity and specificity of the digital rectal examination for the detection of extracapsular disease were 17 and 100%, respectively. The sensitivity and specificity of endorectal ultrasound for the detection of extracapsular disease were 35 and 89%, respectively. The sensitivity and specificity of body coil MRI for the detection of extracapsular disease by adenocarcinoma of the prostate were 47 and 63%, respectively. Microscopic disease of the capsule and seminal vesicles was the principle reason for understaging by both imaging modalities. This small series suggests that both imaging modalities are marginally more sensitive, albeit less specific, for extracapsular disease of the prostate than the digital rectal examination, with ultrasound having a slight edge in specificity and MRI having a slight edge in sensitivity.     

MR imaging in adenocarcinoma of the prostate: interobserver variation and efficacy for determining stage C disease.

Patients with adenocarcinoma of the prostate confined to the gland (stage B) are candidates for a potentially curative surgical procedure (radical retropubic prostatectomy). However, patients with adenocarcinoma that penetrates the capsule or invades the seminal vesicles (stage C) are no longer considered good candidates for surgical cure of their disease. The purpose of this study was to compare the ability of four radiologists to detect stage C disease on MR images and to evaluate interobserver variability. One hundred consecutive MR studies of the prostate were reviewed independently by four radiologists to determine whether the cancer was stage C (capsule penetration or seminal vesicle invasion by tumor). A radical prostatectomy was performed in each case, and careful histologic assessment was made of the prostatic capsule and seminal vesicles for any evidence of stage C disease. The sensitivity, specificity, and accuracy (true-positive + true-negative/100 patients) in detecting stage C disease were calculated for each of the four readers. Four receiver-operating-characteristic curves were generated and compared by means of the univariate z score. Percentage agreement was calculated for five specific areas of the prostate on MR images, and observations made by the best reader were compared with the other three to help determine interreader variability. The results showed that the sensitivity and specificity of MR imaging in detecting stage C disease ranged from .24 to .61 (mean, .48) and .49 to .79 (mean, .66), respectively. The accuracy of MR imaging ranged from .47 to .61 (mean, .55). The univariate z score test showed that one of the readers significantly differed from the other three. The average percentage agreement between that reader and the other three was 70% for the five separate anatomic regions. This study shows that considerable interobserver variation exists in the interpretation of MR images for staging cancer of the prostate. The average accuracy among four radiologists in determining the presence of stage C adenocarcinoma of the prostate from MR images was only slightly above a chance guess at .55.     

Accuracy in staging carcinoma of the bladder by magnetic resonance imaging

Thirty-four patients with a presumptive diagnosis of carcinoma of the bladder diagnosed at EUA and cystoscopy have been staged by MRI and the findings correlated with pathology in 15 patients and clinical follow-up, including repeat cystoscopy, in the remainder. MRI is accurate in identifying tumours confined to the bladder wall or extending beyond the wall to involve perivesical fat or adjacent organs. Whilst it is not possible to distinguish between T1, T2 or early T3a tumours they can be distinguished from advanced T3a lesions and this may affect management. MRI is superior to clinical staging, particularly in detecting lymphadenopathy and provides information for optimal radiotherapy planning. The problem of distinguishing between the effects of radiotherapy and suspected recurrent tumour is discussed.     

MR对声门上型喉癌分期的价值

目的：探讨MR对声门上型喉癌术前T分期的准确性，为治疗方案选择提供影像学依据。方法：对手术切除的48例声门上型喉癌的MR资料进行分析，观察肿瘤侵犯范围及有无颈淋巴结转移，按双盲法根据MR表现进行T分期并与手术病理结果进行对比。结果：NR术前肿瘤T分期的准确性为89．5％(43／48)，判断肿瘤侵犯周围结构的准确性在85％～100％之间，诊断颈部淋巴结的准确性为89％(24／27)。结论：MR能准确判断肿瘤的侵犯范围，准确判断有无淋巴结的转移，对临床治疗方案的选择具有重要意义。     

Characterization of pancreatic adenocarcinoma by magnetic resonance imaging

In the past, magnetic resonance imaging (MRI) of the pancreas has suffered from many technical obstacles that have precluded success, particularly in the evaluation of adenocarcinoma. However, with the improved quality of pancreatic MRI and the use of intravenous gadolinium as a contrast agent, MRI is now proving useful in the evaluation of pancreatic adenocarcinoma. MRI's main role is in accurate preoperative staging when computed tomography and ultrasonography provide equivocal results.     

Accuracy of nasopharyngeal carcinoma staging by magnetic resonance imaging

To audit the accuracy of magnetic resonance (MR) staging of nasopharyngeal carcinoma (NPC) in daily reporting, the MR images of 101 adult patients with newly diagnosed NPC reported between December 1996 and February 2002 were reviewed retrospectively. Based on the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) TNM staging criteria (1997), the tumour staging obtained from the MR reports and the MR films was compared by two experienced head and neck radiologists. The number of patients being upstaged, downstaged or unchanged was noted. In all stages, the NPC staging obtained from the MR reports revealed 18 (17.8%) understaged, eight (7.9%) overstaged and 75 (74.2%) the same stage when compared to the staging obtained from the MR films based on the AJCC/UICC criteria. The percentage of patients being understaged or overstaged, in decreasing order of frequency, were stages II, III, IV and I. Magnetic resonance of NPC should be reported by radiologists who are not only familiar with the pathology of this condition and its pattern of spread but who should also base their reports on the AICC/UICC staging criteria. The necessity to improve our MR staging accuracy is largely because it determines the type of therapy to be given and this has to be appropriate and adequate for a successful treatment.     

Clinical stage B prostate carcinoma: staging with MR imaging

Magnetic resonance (MR) imaging studies were performed in 29 patients with clinical findings of stage B prostatic carcinoma with use of both T1 and T2-weighted spin echo sequences. MR imaging findings were correlated with surgical/pathologic results in 18 patients who underwent an operation. Periprostatic fat, periprostatic venous plexus, seminal vesicles, and lymph nodes were assessed from MR imaging studies. When each was assessed independently, the periprostatic fat signal had a sensitivity of 29%, specificity of 100%, and accuracy of 85% in detecting extracapsular tumor extension, whereas the periprostatic venous plexus had a sensitivity of 57%, specificity of 86%, and accuracy of 80%. MR imaging had a sensitivity of 50%, specificity of 97%, and accuracy of 89% for detecting seminal vesicular involvement. When all four anatomic features were taken into consideration, MR imaging had an accuracy of 89% (16 of 18 patients) in differentiating stage B from stage C or D disease (sensitivity 87%, specificity 90%). Our data indicate that MR imaging is a promising method for staging prostatic carcinoma.     

Uterine cervix cancers: staging by magnetic resonance imaging

The accuracy of Magnetic Resonance Imaging in cervical carcinoma staging for clinical stages superior to IB was studied retrospectively in 27 patients. The MRI results were then correlated with operative findings in 12 cases and with examination carried out under general anesthesia in 15 cases for myometrial, bladder, rectal, parametrial, parietal and vaginal extension. The accuracy of MRI was 81.5% for bladder, 92.5% for rectal, 87% for parametrial and 73% for vaginal extension. The accuracy of staging by MRI was 59%. The contribution of MRI in pre-operative studies for cervical carcinomas has not been properly defined until now. Nevertheless it is a particularly valuable technique due to its non invasive nature.     

MRI对子宫内膜癌术前分期的应用价值

子宫内膜癌又称子宫体癌,是指原发于子宫内膜的上皮恶性肿瘤,是女性生殖系统最常见的恶性肿瘤之一。治疗前准确估计分期、病理分级、淋巴结转移有助于合理选择治疗方案及判断预后。磁共振成像（magnetic resonance imaging,MRI）具有多方位、多角度、多序列成像、组织分辨力高及软组织对比度好等特点,可准确显示盆腔及子宫的解剖结构,并且对病变范围、肌层浸润深度较准确定位,从而可指导临床制定正确的治疗方案。本研究对42例子宫内膜癌行高场强MRI检查,并与手术后病理结果进行对比分析,以期探讨MRI在子宫内膜癌术前分期中的应用价值。     

Diffusion tensor magnetic resonance imaging of prostate cancer

PURPOSE: To explore the feasibility of 3T magnetic resonance (MR) diffusion tensor imaging (DTI) and fiber tracking (FT) in patients with prostate cancer. MATERIALS AND METHODS: Thirty consecutive patients (mean age, 62.5 years) with biopsy proven prostate cancer underwent 3T-MR imaging (MRI) and DTI using a 6-channel external phased-array coil before radical prostatectomy. Regions of interest of 14 pixels were defined in tumors and nonaffected areas in the peripheral zone (PZ) and central gland (CG), according to histopatology after radical prostatectomy. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were determined. Differences in mean ADC and FA values among prostate cancer, normal PZ and CG were compared by 2-sided Student t test. The predominant diffusion direction of the prostate anisotropy was color coded on a directionally encoded color (DEC) map. A 3D reconstruction of fiber tract orientations of the whole prostate was determined using the continuous tracking method. The overall image quality for tumor localization and local staging was assessed in retrospective matching with whole-mount section histopathology images. Nodules detected at MRI were classified as matched lesions if tumor presence and extension were evidenced at histopathology. RESULTS: For all the patients, the DTI sequence images were suitable for the evaluation of the zonal anatomy of the prostate gland and the tumor localization. Quantitative evaluation of the regions of interest (ROIs) showed a mean ADC value significantly lower in the peripheral neoplastic area (1.06 +/- 0.37 x 10(-3) mm2/s) than in the normal peripheral portion (1.95 +/- 0.38 x 10(-3) mm2/s) (P < 0.05). The mean FA values calculated in the normal peripheral (0.47 +/- 0.04) and central area (0.41 +/- 0.08) were very similar (P > 0.05). The mean FA values in the neoplastic lesion (0.27 +/- 0.05) were significantly lower (P < 0.05) than in the normal peripheral area and in the normal central and adenomyomatous area. DEC map showed a top-bottom type preferential direction in the peripheral but not in the central area, with the tumor lesions reducing the diffusion coding direction represented as color zones tending toward gray. Tractographic analysis permitted good delineation of the prostate anatomy (capsule outline, peripheral and central area borders) and neoplastic lesion extension and capsule infiltration compared with histopathology. CONCLUSIONS: Three Tesla DTI of the prostate gland is feasible and has the potential for providing improved diagnostic information.     

宫颈癌的MRI分期与临床及病理分期对照研究

目的:探讨宫颈癌MRI及临床分期价值,并评价MRI对于宫颈癌术前分期的优越性.方法:回顾性分析我院61例具有完整MRI检查及临床资料的宫颈癌患者,参照FIGO分期标准,利用双盲法于术前分别做出宫颈癌的临床及MRI分期.然后进行MRI、临床及术后病理分期的比较.结果:MRI对宫颈癌分期诊断总的准确率为85.2%(52/61),特异性为89.7%(52/58),敏感度达95.1%,临床对宫颈癌总的准确率为63.9%(39/61).结论:MRI对于宫颈癌分期明显优于临床分期,特别对于提示宫颈癌侵犯宫体、宫旁结构及盆腔内淋巴结的转移等方面也更为客观性,应该成为术前常规检查.     

宫颈癌MRI分期与妇科检查分期对比分析

目的 对照妇科检查分期,探讨MRI在宫颈癌尤其是中、晚期宫颈癌分期中的价值。方法 32例具有完整临床及手术病理资料的宫颈癌患者,术前均行MRI检查,将MRI影像分期结果,临床妇科检查分期结果与宫颈癌术后病理分期结果相比较。结果 32例宫颈癌中,MRI分期判断为Iib期以前11例,Iib期（含Iib期）以后21例。与病理结果比较,MRI对二者区分的准确性为93%,对有无宫旁侵犯判断的准确性为94%,敏感性为91%,特异性为94%。妇科检查分期判断为Iib期以前14例,Iib期（含Iib期）以后18例。妇科检查对二者区分的准确性为87%,对有无宫旁侵犯判断的准确性为81%,敏感性为75%,特异性为87%。结论 MRI对早期宫颈癌的诊断及分期尚待改进,但对中晚期宫颈癌及宫颈癌宫旁侵犯,MRI具有重要临床应用价值。