Purpose We determined the positive and negative predictive values of multiparametric magnetic resonance imaging for extraprostatic extension at radical prostatectomy for different prostate cancer ...risk groups. Materials and Methods We evaluated a cohort of 183 patients who underwent 3 Tesla multiparametric magnetic resonance imaging, including T2-weighted, diffusion weighted magnetic resonance imaging and dynamic contrast enhanced sequences, with an endorectal coil before radical prostatectomy. Pathological stage at radical prostatectomy was used as standard reference for extraprostatic extension. The cohort was classified into low, intermediate and high risk groups according to the D’Amico criteria. We recorded prevalence of extraprostatic extension at radical prostatectomy and determined sensitivity, specificity, positive predictive value and negative predictive value of multiparametric magnetic resonance imaging for extraprostatic extension in each group. Univariate and multivariate analyses were performed to identify predictors of extraprostatic extension at radical prostatectomy. Results The overall prevalence of extraprostatic extension at radical prostatectomy was 49.7% ranging from 24.7% to 77.1% between low and high risk categories. Overall staging accuracy of multiparametric magnetic resonance imaging for extraprostatic extension was 73.8%, with sensitivity, specificity, positive predictive value and negative predictive value of 58.2%, 89.1%, 84.1% and 68.3%, respectively. Positive predictive value of multiparametric magnetic resonance imaging for extraprostatic extension was best in the high risk cohort with 88.8%. Negative predictive value was highest in the low risk cohort with 87.7%. With an odds ratio of 10.3 multiparametric magnetic resonance imaging is by far the best preoperative predictor of extraprostatic extension at radical prostatectomy. Conclusions For adequate patient counseling, knowledge of predictive values of multiparametric magnetic resonance imaging for extraprostatic extension is of utmost importance. High negative predictive value, important for decisions on nerve sparing strategies at radical prostatectomy, is only reached in low risk subjects.
Aim To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of lymph node metastases in prostate cancer. Methods After a comprehensive ...literature search, studies were included that allowed construction of contingency tables for detection of lymph node metastases using CT or MRI. In addition, a summary receiver-operating characteristic (ROC) analysis was performed. Results A total of 24 studies were included. For CT, pooled sensitivity was 0.42 (0.26–0.56 95% CI) and pooled specificity was 0.82 (0.8–0.83 95% CI). For MRI, the pooled sensitivity was 0.39 (0.22–0.56 95% CI) and pooled specificity was 0.82 (0.79–0.83 95% CI). The differences in performance of CT and MRI were not statistically significant. Conclusion CT and MRI demonstrate an equally poor performance in the detection of lymph node metastases from prostate cancer. Reliance on either CT or MRI will misrepresent the patient's true status regarding nodal metastases, and thus misdirect the therapeutic strategies offered to the patient.
Re-excision rates after breast conserving surgery (BCS) of invasive lobular carcinoma (ILC) are high. Preoperative breast MRI has the potential to reduce re-excision rates, but may lead to an ...increased rate of mastectomies. Hence, we assessed the influence of preoperative breast MRI on the re-excision rate and the rate of mastectomies. We performed a retrospective cohort study of a consecutive series of patients with ILC who presented in one of two dedicated tertiary cancer centers between 1993 and 2005. We assessed the initial type of surgery (BCS or mastectomy), the re-excision rate and the final type of surgery. Patients were stratified into two groups: those who received preoperative MRI (MR+ group) and those who did not (MR− group). In the MR− group, 27% of the patients underwent a re-excision after initial BCS. In the MR+ group, this rate was significantly lower at 9%. The odds ratio was 3.64 (95% CI: 1.30-10.20, P = 0.010). There was a trend towards a lower final mastectomy rate in the MR+ group compared to the MR− group (48 vs. 59%, P = 0.098). In conclusion, preoperative MRI in patients with ILC can reduce re-excision rates without increasing the rate of mastectomies.
In this paper, a fully automatic computer-aided detection (CAD) method is proposed for the detection of prostate cancer. The CAD method consists of multiple sequential steps in order to detect ...locations that are suspicious for prostate cancer. In the initial stage, a voxel classification is performed using a Hessian-based blob detection algorithm at multiple scales on an apparent diffusion coefficient map. Next, a parametric multi-object segmentation method is applied and the resulting segmentation is used as a mask to restrict the candidate detection to the prostate. The remaining candidates are characterized by performing histogram analysis on multiparametric MR images. The resulting feature set is summarized into a malignancy likelihood by a supervised classifier in a two-stage classification approach. The detection performance for prostate cancer was tested on a screening population of 200 consecutive patients and evaluated using the free response operating characteristic methodology. The results show that the CAD method obtained sensitivities of 0.41, 0.65 and 0.74 at false positive (FP) levels of 1, 3 and 5 per patient, respectively. In conclusion, this study showed that it is feasible to automatically detect prostate cancer at a FP rate lower than systematic biopsy. The CAD method may assist the radiologist to detect prostate cancer locations and could potentially guide biopsy towards the most aggressive part of the tumour.
Summary The development of targeted therapies is a major breakthrough in the treatment of cancer. By evoking necrosis and cavitation, evaluation based on tumour size alone, as is done in the RECIST ...criteria, is no longer an adequate method. New molecular and functional imaging techniques are developed. This review focuses on the use of new imaging modalities for the evaluation of treatment response of pathway based targeted therapies. First, the basic principles of functional and molecular imaging modalities are briefly discussed. Thereafter, their clinical application in targeted therapies is correlated to the underlying biological mechanism. In this way, the best method for response evaluation for a new agent can be identified.
Background: Although breast cancer screening is recommended to start at a younger age for women with a hereditary risk of breast cancer, the sensitivity of mammography for these women is reduced. We ...compared magnetic resonance imaging (MRI) with mammography to determine which is more sensitive and whether MRI could play a role in the early detection of breast cancer for these women. Methods: We constructed a retrospective cohort of all breast MRI and mammography surveillance reports made in our department from November 1994 to February 2001. All of the 179 women in the cohort had received biannual palpation in addition to annual imaging by MRI, mammography, or both. The 258 MRI images and the 262 mammograms were classified with the use of the BI-RADSTM (i.e., Breast Imaging Reporting and Data System) scoring system, which has five categories to indicate the level of suspicion of a lesion. Receiver operator characteristic curves were generated for MRI and mammography, and the area under each curve (AUC) was assessed for the entire cohort of 179 women and for a subset of 75 women who had received both an MRI and a mammographic examination within a 4-month period. All statistical tests were two-sided. Results: In the cohort of 179 women, we detected 13 breast cancers. Seven cancers were not revealed by mammography, but all were detected by MRI. For the entire cohort, the AUC for mammography was 0.74 (95% confidence interval CI = 0.68 to 0.79), and the AUC for MRI was 0.99 (95% CI = 0.98 to 1.0). For the subset of women who had both examinations, the AUC for mammography was 0.70 (95% CI = 0.60 to 0.80), and the AUC for MRI was 0.98 (95% CI = 0.95 to 1.0). Conclusion: MRI was more accurate than mammography in annual breast cancer surveillance of women with a hereditary risk of breast cancer. Larger prospective studies to examine the role of MRI in screening programs are justified.
The success of cellular therapies will depend in part on accurate delivery of cells to target organs. In dendritic cell therapy, in particular, delivery and subsequent migration of cells to regional ...lymph nodes is essential for effective stimulation of the immune system. We show here that in vivo magnetic resonance tracking of magnetically labeled cells is feasible in humans for detecting very low numbers of dendritic cells in conjunction with detailed anatomical information. Autologous dendritic cells were labeled with a clinical superparamagnetic iron oxide formulation or (111)In-oxine and were co-injected intranodally in melanoma patients under ultrasound guidance. In contrast to scintigraphic imaging, magnetic resonance imaging (MRI) allowed assessment of the accuracy of dendritic cell delivery and of inter- and intra-nodal cell migration patterns. MRI cell tracking using iron oxides appears clinically safe and well suited to monitor cellular therapy in humans.
The purpose of this study was to define guidelines for endometrial cancer staging with MRI. The technique included critical review and expert consensus of MRI protocols by the female imaging ...subcommittee of the European Society of Urogenital Radiology, from ten European institutions, and published literature between 1999 and 2008. The results indicated that high field MRI should include at least two T2-weighted sequences in sagittal, axial oblique or coronal oblique orientation (short and long axis of the uterine body) of the pelvic content. High-resolution post-contrast images acquired at 2 min ± 30 s after intravenous contrast injection are suggested to be optimal for the diagnosis of myometrial invasion. If cervical invasion is suspected, additional slice orientation perpendicular to the axis of the endocervical channel is recommended. Due to the limited sensitivity of MRI to detect lymph node metastasis without lymph node-specific contrast agents, retroperitoneal lymph node screening with pre-contrast sequences up to the level of the kidneys is optional. The likelihood of lymph node invasion and the need for staging lymphadenectomy are also indicated by high-grade histology at endometrial tissue sampling and by deep myometrial or cervical invasion detected by MRI. In conclusion, expert consensus and literature review lead to an optimized MRI protocol to stage endometrial cancer.
Abstract Aims Invasive lobular carcinoma of the breast (ILC) is known to be substantially underestimated by mammography, which makes correct planning of treatment difficult. MRI has been proposed as ...a valuable adjunct to mammography. The purpose of the current study is to evaluate its value, compare it to mammography and assess the possible causes of over- and underestimation of lesion size on MRI. Method The mammograms and MRI scans of 67 consecutive patients with ILC were retrieved and re-evaluated. Size measurements were correlated to the sizes extracted from the pathology report. Results MRI measurements correlated better to pathologic size ( r = 0.85) than mammographic measurements ( r = 0.27). Underestimation of tumour size was more common on mammography ( p < 0.001); overestimation occurred with equal frequency ( p = 0.69). Overestimation on MRI, caused by non-malignant findings, was attributed to enhancing lobular carcinoma in situ. Conclusion MRI is a more accurate modality for determining tumour size in patients with ILC than mammography. The typical underestimation of lesion size by mammography can be prevented with the aid of MRI, without increasing the risk of lesion overestimation.
To evaluate the comparative accuracy of magnetic resonance (MR) imaging relative to mammography and ultrasonography (US) for assessing the extent of breast tumors.
Histologic results and preoperative ...imaging findings (mammography, US, MR imaging) were analyzed regarding tumor size and multifocality of 61 tumors in 60 women undergoing mastectomy for carcinoma.
In 10% of cases, the index tumor was not seen at mammography. With US, 15% of the index tumors were not recognized, while MR imaging missed 2% of the index tumors. On mammographic and US images, tumor size was underestimated significantly (P < .005), by 14% and 18%, respectively, while MR imaging showed no significant difference in size compared with that found in a pathologic evaluation. Mammography showed 31% of the additional invasive lesions, while US showed 38% and MR imaging showed 100%.
MR imaging was the most accurate of the three preoperative imaging modalities in assessing the size and number of malignant lesions in the breast.
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