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1 maart 2012, Contains fulltext : 108364.pdf (publisher's version ) (Closed access), INTRODUCTION: Diffusion-weighted magnetic resonance (MR) imaging (DWI) might be able to fulfill the need to accurately identify high-grade prostate carcinoma, in patients initially selected for active surveillance in the Prostate Specific Antigen (PSA) screening era based on transrectal ultrasound-guided biopsy Gleason score. We aimed to determine whether DWI is able to correctly identify those patients with a biopsy Gleason score of

01 juli 2012, Contains fulltext : 108222.pdf (Publisher’s version ) (Open Access), Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. Key Points * Tumour vascular function is key to tumour development and treatment * Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess tumour vascular function * Thus DCE-MRI with pharmacokinetic models can assess novel treatments * Many recent developments are advancing the accuracy of and information from DCE-MRI * Establishing common methodology across multiple centres is challenging and requires accepted guidelines.

1 januari 2012, Item does not contain fulltext, Multiparametric magnetic resonance imaging (MRI) has the potential of being the ideal prostate cancer (PCa) assessment tool. Information gathered with multiparametric MRI can serve therapy choice, guidance of interventions, and treatments. The purpose of this review is to discuss the potential role of multiparametric MRI in focal therapy with respect to patient selection and directing (robot-guided) biopsies and intensity-modulated radiation therapy (IMRT). Multiparametric MRI is a versatile and promising technique. It appears to be the best available imaging technique at the moment in localizing, staging (primary as well as recurrent disease, and local as well as distant disease), determining aggressiveness, and volume of PCa. However, larger study populations in multicenter settings have to confirm these promising results. However, before such studies can be performed more research is needed in order to achieve standardized imaging protocols.

Item does not contain fulltext, OBJECTIVE: The purpose of this article is to evaluate MRI-guided therapies and to investigate their feasibility for focal therapy in prostate cancer patients. Relevant articles were retrieved using the PubMed online search engine. CONCLUSION: Currently, MRI-guided laser ablation and MRI-guided focused ultrasound are the most promising options for focal treatment of the prostate in patients with prostate cancer. Other techniques-that is, cryosurgery, microwave ablation, and radiofrequency ablation-are, for several and different reasons, less suitable for MRI-guided focal therapy of the prostate.

Contains fulltext : 108122.pdf (publisher's version ) (Closed access), Transrectal ultrasound-guided biopsy is the gold standard for prostate cancer detection. The latter detection rates of random systematic TRUS-guided biopsy do not exceed 44\%. As a consequence other biopsy methods have been explored. One of these methods is MR-guided biopsy (MRGB), which revealed detection rates of 38-59\% after previous negative TRUSGB sessions. For this reason MRGB will probably become more and more applied in daily practice.

Contains fulltext : 109210.pdf (publisher's version ) (Closed access), Purpose: To determine the individual and combined performance of magnetic resonance (MR) spectroscopic imaging and diffusion-weighted (DW) imaging at 3 T in the in vivo assessment of prostate cancer aggressiveness by using histopathologically defined regions of interest on radical prostatectomy specimens to define the prostate cancer regions to be investigated. Materials and Methods: The local institutional ethics review board approved this retrospective study and waived the informed consent requirement. Fifty-four patients with biopsy-proved prostate cancer underwent clinical MR spectroscopic imaging followed by prostatectomy. Guided by the histopathologic map, all spectroscopy voxels that contained tumor tissue were selected, and metabolite ratios (choline [Cho] plus creatine [Cr]-to-citrate [Cit] and Cho/Cr ratios) were derived. For each spectroscopic voxel, 25th percentile apparent diffusion coefficient (ADC) of the region corresponding to that voxel was determined, representing the most aberrant tumor part on the ADC map, which was often smaller than spectroscopic imaging voxels. Maximum metabolic ratios and minimum 25th percentile ADC of each tumor were related to tumor aggressiveness and were used to differentiate aggressiveness classes. A logistic regression model (LRM) was used to combine data from both modalities. Results: Significant correlation was found between aggressiveness classes and maximum Cho+Cr/Cit ratio (rho = 0.36), maximum Cho/Cr ratio (rho = 0.35), and minimum 25th percentile ADC (rho = -0.63) in the peripheral zone (PZ). In the transition zone (TZ), the correlation was significant for only Cho+Cr/Cit and Cho/Cr ratios (rho = 0.58 and rho = 0.60, respectively). For differentiation between aggressiveness classes, LRM use did not result in significantly improved differentiation over any individual variables. Conclusion: These findings enabled confirmation that MR spectroscopic imaging and DW imaging offer potential for in vivo noninvasive asse

Contains fulltext : 108408.pdf (Publisher’s version ) (Open Access), Purpose: To determine the interpatient variability of prostate peripheral zone (PZ) apparent diffusion coefficient (ADC) and its effect on the assessment of prostate cancer aggressiveness. Materials and Methods: The requirement for institutional review board approval was waived. Intra- and interpatient variation of PZ ADCs was determined by means of repeated measurements of normal ADCs at three magnetic resonance (MR) examinations in a retrospective cohort of 10 consecutive patients who had high prostate-specific antigen levels and negative findings at transrectal ultrasonographically-guided biopsy. In these patients, no signs of PZ cancer were found at all three MR imaging sessions. The effect of interpatient variation on the assessment of prostate cancer aggressiveness was examined in a second retrospective cohort of 51 patients with PZ prostate cancer. Whole-mount step-section pathologic evaluation served as reference standard for placement of regions of interest on tumors and normal PZ. Repeated-measures analysis of variance was used to determine the significance of the interpatient variations in ADCs. Linear logistic regression was used to assess whether incorporating normal PZ ADCs improves the prediction of cancer aggressiveness. Results: Analysis of variance revealed that interpatient variability (1.2-2.0 x 10(-3) mm(2)/sec) was significantly larger than measurement variability (0.068 x 10(-3) mm(2)/sec +/- 0.027 [standard deviation]) (P = .0058). Stand-alone tumor ADCs showed an area under the receiver operating characteristic curve (AUC) of 0.91 for discriminating low-grade versus high-grade tumors. Incorporating normal PZ ADC significantly improved the AUC to 0.96 (P = .0401). Conclusion: PZ ADCs show significant interpatient variation, which has a substantial effect on the prediction of prostate cancer aggressiveness. Correcting this effect results in a significant increase in diagnostic accuracy. (c) RSNA, 2012.

Radboud Universiteit Nijmegen, 25 januari 2012, Promotor : Barentsz, J.O. Co-promotores : Jager, G.J., Hoogeveen, Y.L., Contains fulltext : 108595.pdf (Publisher’s version ) (Open Access)

Radboud Universiteit Nijmegen, 8 december 2011, Promotores : Barentsz, J.O., Karssemeijer, N. Co-promotor : Huisman, H.J., Contains fulltext : 91387.pdf (publisher's version ) (Open Access)

Item does not contain fulltext, OBJECTIVES: A prospective multicenter validation of the ability of 1H magnetic resonance spectroscopic imaging (MRSI) to distinguish cancer from noncancer tissues throughout the prostate with histopathology of the resected organ as the standard of reference. MATERIALS AND METHODS: Institutional review board approval was obtained for all centers and all participating patients and volunteers provided written informed consent. Ninety-nine patients and 10 age-matched volunteers from 8 participating centers underwent magnetic resonance imaging and 3-dimensional MRSI with an endorectal coil at 1.5 T. Selected MRSI voxels were assigned to the peripheral zone (PZ), the central gland (CG), the periurethral area, and cancer tissue. Signal ratios of choline + creatine to citrate (CC/C) in spectra of these voxels were automatically calculated. Receiver operating characteristic curves were constructed to assess the accuracy by which this ratio can discriminate cancer from noncancer tissue. RESULTS: A total of 70% of voxels in noncancer tissue and 90% of voxels in cancer tissue passed the quality check of the automatically fitted spectra. The median CC/C was significantly different between any noncancer and cancer tissue (P < 0.0001), but not between the different contributing centers. CC/C increased with cancer focus size (P =0.0008) and certainty of voxel mapping to histopathologic cancer site (P 0.0001). The area under the receiver operating characteristic curve for discriminating voxels of cancer tissue from noncancer tissue was 0.88 (confidence interval: 0.84-0.92) in the PZ and 0.76 (confidence interval: 0.71- 0.81) in the CG.

Radboud Universiteit Nijmegen, 16 november 2011, Promotores : Barentsz, J.O., Karssemeijer, N. Co-promotor : Huisman, H.J., Contains fulltext : 95664.pdf (Publisher’s version ) (Open Access)

Item does not contain fulltext, PURPOSE: To assess the feasibility of using a remote-controlled, pneumatically actuated magnetic resonance (MR)-compatible robotic device to aid transrectal biopsy of the prostate performed with real-time 3-T MR imaging guidance. MATERIALS AND METHODS: This prospective study was approved by the ethics review board, and written informed consent was obtained from all patients. Twelve consecutive men who were clinically suspected of having prostate cancer and had a history of at least one transrectal ultrasonography (US)-guided prostate biopsy with negative results underwent diagnostic multiparametric MR imaging of the prostate. Two radiologists in consensus identified cancer-suspicious regions (CSRs) in 10 patients. These regions were subsequently targeted with the robot for MR imaging-guided prostate biopsy. To direct the needle guide toward the CSRs, the MR-compatible robotic device was remote controlled at the MR console by means of a controller and a graphical user interface for real-time MR imaging guidance of the needle guide. The ability to reach the CSRs with the robot for biopsy was analyzed. RESULTS: A total of 17 CSRs were detected in 10 patients at the diagnostic MR examinations. These regions were targeted for MR imaging-guided robot-assisted prostate biopsy. Thirteen (76%) of the 17 CSRs could be reached with the robot for biopsy. Biopsy of the remaining four CSRs was performed without use of the robot. CONCLUSION: It is feasible to perform transrectal prostate biopsy with real-time 3-T MR imaging guidance with the aid of a remote-controlled, pneumatically actuated MR-compatible robotic device.

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Item does not contain fulltext, BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) may have a role in detecting clinically significant prostate cancer in men with raised serum prostate-specific antigen levels. Variations in technique and the interpretation of images have contributed to inconsistency in its reported performance characteristics. OBJECTIVE: Our aim was to make recommendations on a standardised method for the conduct, interpretation, and reporting of prostate mpMRI for prostate cancer detection and localisation. DESIGN, SETTING, AND PARTICIPANTS: A consensus meeting of 16 European prostate cancer experts was held that followed the UCLA-RAND Appropriateness Method and facilitated by an independent chair. MEASUREMENT: Before the meeting, 520 items were scored for "appropriateness" by panel members, discussed face to face, and rescored. RESULTS AND LIMITATIONS: Agreement was reached in 67% of 260 items related to imaging sequence parameters. T2-weighted, dynamic contrast-enhanced, and diffusion-weighted MRI were the key sequences incorporated into the minimum requirements. Consensus was also reached on 54% of 260 items related to image interpretation and reporting, including features of malignancy on individual sequences. A 5-point scale was agreed on for communicating the probability of malignancy, with a minimum of 16 prostatic regions of interest, to include a pictorial representation of suspicious foci. Limitations relate to consensus methodology. Dominant personalities are known to affect the opinions of the group and were countered by a neutral chairperson. CONCLUSIONS: Consensus was reached on a number of areas related to the conduct, interpretation, and reporting of mpMRI for the detection, localisation, and characterisation of prostate cancer. Before optimal dissemination of this technology, these outcomes will require formal validation in prospective trials.

Item does not contain fulltext, OBJECTIVE: The increasing importance of breast MRI in the diagnostic processes concerning breast cancer yield often lesions that are visible on MRI only. To assess the nature of these lesions, pathologic analysis is necessary. Therefore, MR-guided biopsy should be available. Breast MRI at 3T has shown advantage over 1.5T. Unfortunately, current equipment for MR-guided biopsy is better suited for intervention at 1.5T due to the danger of heating titanium co-axial sleeves and large susceptibility artifacts. We evaluated a dedicated 3T breast biopsy set that uses plastic coaxial needles to overcome these problems. MATERIALS AND METHODS: We performed MRI-guided breast biopsy in 23 women with 24 MRI-only visible breast lesions at 3T. Biopsy procedures were performed with plastic coaxial needles in a closed bore 3T clinical MR system on a dedicated phased array breast coil with a commercially available add-on stereotactic biopsy device. RESULTS: Width of the needle artifact was 2mm in all 24 cases. Biopsy procedure was completed between 35 and 67 min. The procedure was judged moderately easy in 12 and normal in 10 cases. One procedure was judged difficult and there was one technical failure. CONCLUSION: MRI-guided breast biopsy at 3T is a fast and accurate procedure. The plastic coaxial needles reduce the susceptibility artifact largely and do not increase the difficulty of the procedure. The diagnostic yield is at least equal to the diagnostic yield of the same procedure at 1.5T. Therefore, this technique can be safely used for lesions only visible at 3T MRI.

Contains fulltext : 96236.pdf (Publisher’s version ) (Open Access), This review presents the current state of the art regarding multiparametric magnetic resonance (MR) imaging of prostate cancer. Technical requirements and clinical indications for the use of multiparametric MR imaging in detection, localization, characterization, staging, biopsy guidance, and active surveillance of prostate cancer are discussed. Although reported accuracies of the separate and combined multiparametric MR imaging techniques vary for diverse clinical prostate cancer indications, multiparametric MR imaging of the prostate has shown promising results and may be of additional value in prostate cancer localization and local staging. Consensus on which technical approaches (field strengths, sequences, use of an endorectal coil) and combination of multiparametric MR imaging techniques should be used for specific clinical indications remains a challenge. Because guidelines are currently lacking, suggestions for a general minimal protocol for multiparametric MR imaging of the prostate based on the literature and the authors' experience are presented. Computer programs that allow evaluation of the various components of a multiparametric MR imaging examination in one view should be developed. In this way, an integrated interpretation of anatomic and functional MR imaging techniques in a multiparametric MR imaging examination is possible. Education and experience of specialist radiologists are essential for correct interpretation of multiparametric prostate MR imaging findings. Supportive techniques, such as computer-aided diagnosis are needed to obtain a fast, cost-effective, easy, and more reproducible prostate cancer diagnosis out of more and more complex multiparametric MR imaging data.

Contains fulltext : 98019.pdf (Publisher’s version ) (Open Access), PURPOSE: The purpose of this study was to compare the diagnostic performance of 3 Tesla, 3-dimensional (3D) magnetic resonance spectroscopic imaging (MRSI) in the localization of prostate cancer (PCa) with and without the use of an endorectal coil (ERC). MATERIALS AND METHODS: Our prospective study was approved by the institutional review board, and written informed consent was obtained from all patients. Between October 2004 and January 2006, 18 patients with histologically proven PCa on biopsy and scheduled for radical prostatectomy were included and underwent 3D-MRSI with and without an ERC. The prostate was divided into 14 regions of interest (ROIs). Four readers independently rated (on a 5-point scale) their confidence that cancer was present in each of these ROIs. These findings were correlated with whole-mount prostatectomy specimens. Areas under the receiver-operating characteristic curve were determined. A difference with a P < 0.05 was considered significant. RESULTS: A total of 504 ROIs were rated for the presence and absence of PCa. Localization of PCa with MRSI with the use of an ERC had a significantly higher areas under the receiver-operating characteristic curve (0.68) than MRSI without the use of an ERC (0.63) (P = 0.015). CONCLUSION: The use of an ERC in 3D MRSI in localizing PCa at 3 Tesla slightly but significantly increased the localization performance compared with not using an ERC.

1 april 2011, Item does not contain fulltext

Contains fulltext : 97304.pdf (publisher's version ) (Closed access), PURPOSE: To retrospectively determine the relationship between apparent diffusion coefficients (ADCs) obtained with 3.0-T diffusion-weighted (DW) magnetic resonance (MR) imaging and Gleason grades in peripheral zone prostate cancer. MATERIALS AND METHODS: The requirement to obtain institutional review board approval was waived. Fifty-one patients with prostate cancer underwent MR imaging before prostatectomy, including DW MR imaging with b values of 0, 50, 500, and 800 sec/mm(2). In prostatectomy specimens, separate slice-by-slice determinations of Gleason grade groups were performed according to primary, secondary, and tertiary Gleason grades. In addition, tumors were classified into qualitative grade groups (low-, intermediate-, or high-grade tumors). ADC maps were aligned to step-sections and regions of interest annotated for each tumor slice. The median ADC of tumors was related to qualitative grade groups with linear mixed-model regression analysis. The accuracy of the median ADC in the most aggressive tumor component in the differentiation of low- from combined intermediate- and high-grade tumors was summarized by using the area under the receiver operating characteristic (ROC) curve (A(z)). RESULTS: In 51 prostatectomy specimens, 62 different tumors and 251 step-section tumor lesions were identified. The median ADC in the tumors showed a negative relationship with Gleason grade group, and differences among the three qualitative grade groups were statistically significant (P < .001). Overall, with an increase of one qualitative grade group, the median ADC (+/-standard deviation) decreased 0.18 x 10(-3) mm(2)/sec +/- 0.02. Low-, intermediate-, and high-grade tumors had a median ADC of 1.30 x 10(-3) mm(2)/sec +/- 0.30, 1.07 x 10(-3) mm(2)/sec +/- 0.30, and 0.94 x 10(-3) mm(2)/sec +/- 0.30, respectively. ROC analysis showed a discriminatory performance of A(z) = 0.90 in discerning low-grade from combined intermediate- and high-grade lesions. CONCLUSION: ADCs at 3

Radboud Universiteit Nijmegen, 27 september 2011, Promotor : Barentsz, J.O. Co-promotores : Mann, R.M., Hall, H.N. van, Contains fulltext : 91223.pdf (publisher's version ) (Open Access)

Item does not contain fulltext, PURPOSE: Evaluation of the lymph node situation in patients with prostate cancer is essential for effective radiotherapy. Using magnet resonance imaging (MRI) of the lymph nodes with ferumoxtran-10 (MR lymphography), it is possible to detect lymph node metastasis. We present our initial experience with ferumoxtran-10 MR lymphography as the basis for image-guided, dose-escalated lymph node radiotherapy and for early follow-up after radiotherapy. PATIENTS AND METHODS: A patient with suspicion for lymph node metastasis after radical prostatectomy was examined with MR lymphography with the lymph node-specific contrast media ferumoxtran-10. Radiotherapy was performed as intensity-modulated radiotherapy with a total dose of 44 Gy to the whole lymphatic drainage, 60 Gy to the area of affected lymph nodes, 71 Gy to the prostate bed, and 75 Gy to the anastomosis region. 8 weeks after completion of radiotherapy, a follow-up MR lymphography with ferumoxtran-10 was performed. RESULTS: In the first MRI with ferumoxtran-10, 5 metastatic lymph nodes were found in the iliac region. The scan 8 weeks postradiotherapy no longer showed lymph nodes suspicious for metastases. PSA (prostate-specific antigen) decreased from 2.06 ng/ml pretherapeutically to 0.02 ng/ml at 2 weeks after treatment and was no longer detectable at 8 months after treatment. CONCLUSIONS: Lymph node staging with ferumoxtran-10 and subsequent dose escalation with intensity-modulated radiotherapy led to the elimination of positive lymph nodes and a decrease in the PSA value.

Contains fulltext : 96814.pdf (publisher's version ) (Closed access), Pilot study evaluating the diagnostic value of magnetic resonance lymphography (MRL) compared with conventional imaging techniques in the preoperative staging of the clinically (palpable) negative neck (cN0) in squamous cell carcinoma of the oral cavity (SCCOC). Patients with SCCOC without clinical evidence of lymph node metastasis and scheduled for surgery underwent MRL in combination with ultrasound with or without fine needle aspiration cytology and multi-detector computer tomography. MRL images were interpreted by 2 independent radiologists. All patients were planned for resection of the primary tumor and a selective neck dissection of levels I-III. Histopathologic results were evaluated as the gold standard and compared with preoperative findings. One of nine evaluated patients had a metastatic node on histopathologic analysis. In all but 1 patient, MRL showed possible metastatic spread in at least 1 node. On a node-to-node basis, negative predictive value (NPV) and sensitivity reached 100% for 1.5- en 3Tesla (T) MRL, specificity reached 92% at 1.5T and 93% at 3T MRL, and positive predictive value (PPV) was 8% at 1.5T MRL, for both radiologists. PPV at 3T MRL was 10% and 9%, for radiologists I and II, respectively. This pilot study shows that MRL has a high NPV based on a node-to-node analysis. However, its PPV was only 10%, and therefore its use as a single imaging technique in the preoperative staging of the cN0 neck in SCCOC seems to be limited. Further studies are needed to confirm these data.

Contains fulltext : 97997.pdf (publisher's version ) (Closed access), BACKGROUND: One of the most important clinical challenges in prostate cancer (PCa) management is an in vivo assessment of cancer aggressiveness. OBJECTIVE: To validate the performance of magnetic resonance (MR) spectroscopic imaging (MRSI) of the prostate at 3 T for the purpose of assessing tumour aggressiveness based on the ratio of choline plus creatine to citrate (Cho+Cr/Cit) and of choline to creatine (Cho/Cr), using the Gleason score of the radical prostatectomy (RP) specimen as the gold standard. DESIGN, SETTING, AND PARTICIPANTS: A total of 43 biopsy-proven PCa patients with 53 clinically relevant tumour foci were retrospectively included in this study. MEASUREMENTS: Patients underwent MR imaging and MRSI examination followed by RP. From MRSI, all spectroscopy voxels containing tumour were selected by a radiologist guided by the prostatectomy histopathology map only. For each tumour, two spectroscopists determined the maximum Cho+Cr/Cit, Cho/Cr, and malignancy rating using a standardised threshold approach, incorporating both metabolic ratios. The maximum Cho+Cr/Cit, Cho/Cr, and malignancy ratings showed a relation to tumour aggressiveness and so were used to differentiate among tumour aggressiveness classes. RESULTS AND LIMITATIONS: The maximum Cho+Cr/Cit ratio, maximum Cho/Cr ratio, and malignancy rating of a standardised threshold approach separated low-grade from higher-grade tumours, with areas under the receiver operating characteristic (ROC) curves of 0.70, 0.74, and 0.78, respectively. CONCLUSIONS: MRSI offers possibilities for an in vivo, noninvasive assessment of PCa aggressiveness. The combination of the different metabolite ratios was used with promising results for discrimination among different aggressiveness classes.

Contains fulltext : 97614.pdf (publisher's version ) (Closed access), 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 o

Item does not contain fulltext, PURPOSE: To compare the nodal risk formula (NRF) as a predictor for lymph node (LN) metastasis in patients with prostate cancer with magnetic resonance lymphography (MRL) using Ultrasmall Super-Paramagnetic particles of Iron Oxide (USPIO) and with histology as gold standard. METHODS AND MATERIALS: Logistic regression analysis was performed with the results of histopathological evaluation of the LN as dependent variable and the nodal risk according to the NRF and the result of MRL as independent input variables. Receiver operating characteristic (ROC) analysis was performed to assess the performance of the models. RESULTS: The analysis included 375 patients. In the single-predictor regression models, the NRF and MRL results were both significantly (p<0.001) predictive of the presence of LN metastasis. In the models with both predictors included, NRF was nonsignificant (p=0.126), but MRL remained significant (p<0.001). For NRF, sensitivity was 0.79 and specificity was 0.38; for MRL, sensitivity was 0.82 and specificity was 0.93. After a negative MRL result, the probability of LN metastasis is 4% regardless of the NRF result. After a positive MRL, the probability of having LN metastasis is 68%. CONCLUSIONS: MRL is a better predictor of the presence of LN metastasis than NRF. Using only the NRF can lead to a significant overtreatment on the pelvic LN by radiation therapy. When the MRL result is available, the NRF is no longer of added value.

01 februari 2011, Contains fulltext : 96235.pdf (publisher's version ) (Closed access), CONTEXT: We addressed the question whether the change of serum prostate-specific antigen (PSA) in men who use 5alpha-reductase inhibitor (5-ARI) dutasteride is sensitive for the detection of aggressive prostate cancer (PCa). OBJECTIVE: The case of a man using dutasteride diagnosed with Gleason 7 transition zone cancer at biopsy indicated by a rising PSA is described. The following issues are discussed: (1) Is a rise of PSA in patients using dutasteride predictive of aggressive PCa in men with prior negative biopsies? (2) Is it safe not to biopsy men using dutasteride who do not show a rising PSA? (3) How can we avoid potentially unnecessary biopsies in men using dutasteride without a rising PSA? EVIDENCE ACQUISITION: We reviewed the recent literature addressing our objective that relates to two studies: the Prostate Cancer Prevention Trial and the Reduction by Dutasteride of Prostate Cancer Events trial. EVIDENCE SYNTHESIS: In men using dutasteride, the positive predictive value/detection rate of Gleason 7-10 PCa is 13.2% and 4.0% for men with and without a rising PSA, respectively. However, a substantial proportion of Gleason 7-10 cases (42.9%) would be missed if a rising PSA was used as the only biopsy indication. Currently available data do not provide selective mechanisms to diagnose these cancers. CONCLUSIONS: A rising PSA for a patient using dutasteride should be an indication for prostate biopsies. Currently, in the case of stable PSA a biopsy may still be considered. Options for a selective approach are therefore suggested in this review to avoid unnecessary biopsies and to achieve a more selective PCa detection in men on 5-ARI treatment.

1 juni 2010, Contains fulltext : 89793.pdf (publisher's version ) (Closed access), INTRODUCTION AND HYPOTHESIS: The aim of this dynamic magnetic resonance (MR) imaging study was to assess the relation between the position and mobility of the perineum and patients' symptoms of pelvic floor dysfunction. METHODS: Patients' symptoms were measured with the use of validated questionnaires. Univariate logistic regression analyses were used to study the relationship between the questionnaires domain scores and the perineal position on dynamic MR imaging, as well as baseline characteristics (age, body mass index, and parity). RESULTS: Sixty-nine women were included in the analysis. Only the domain score genital prolapse was associated with the perineal position on dynamic MR imaging. This association was strongest at rest. CONCLUSIONS: Pelvic organ prolapse symptoms were associated with the degree of descent of the perineum on dynamic MR imaging. Perineal descent was not related to anorectal and/or urinary incontinence symptoms.

Contains fulltext : 89494.pdf (Publisher’s version ) (Open Access), In this study, computer-assisted analysis of prostate lesions was researched by combining information from two different magnetic resonance (MR) modalities: T2-weighted (T2-w) and dynamic contrast-enhanced (DCE) T1-w images. Two issues arise when incorporating T2-w images in a computer-aided diagnosis (CADx) system: T2-w values are position as well as sequence dependent and images can be misaligned due to patient movement during the acquisition. A method was developed that computes T2 estimates from a T2-w and proton density value and a known sequence model. A mutual information registration strategy was implemented to correct for patient movement. Global motion is modelled by an affine transformation, while local motion is described by a volume preserving non-rigid deformation based on B-splines. The additional value to the discriminating performance of a DCE T1-w-based CADx system was evaluated using bootstrapped ROC analysis. T2 estimates were successfully computed in 29 patients. T2 values were extracted and added to the CADx system from 39 malignant, 19 benign and 29 normal annotated regions. T2 values alone achieved a diagnostic accuracy of 0.85 (0.77-0.92) and showed a significantly improved discriminating performance of 0.89 (0.81-0.95), when combined with DCE T1-w features. In conclusion, the study demonstrated a simple T2 estimation method that has a diagnostic performance such that it complements a DCE T1-w-based CADx system in discriminating malignant lesions from normal and benign regions. Additionally, the T2 estimate is beneficial to visual inspection due to the removed coil profile and fixed window and level settings.

RU Radboud Universiteit Nijmegen, 10 maart 2010, Promotores : Vierhout, M.E., Barentsz, J.O. Co-promotores : Kluivers, K.B., Futterer, J.J., Hendriks, J.C.M., Contains fulltext : 88815.pdf (Publisher’s version ) (Open Access)

01 maart 2010, Contains fulltext : 88584.pdf (Publisher’s version ) (Open Access), OBJECTIVES: The objective of this study was to assess the feasibility of the combination of magnetic resonance (MR)-guided biopsy (MRGB) and diagnostic 3T MR imaging in the localization of local recurrence of prostate cancer (PCa) after external beam radiation therapy (EBRT). MATERIALS AND METHODS: Twenty-four consecutive men with biochemical failure suspected of local recurrence after initial EBRT were enrolled prospectively in this study. All patients underwent a diagnostic 3T MR examination of the prostate. T2-weighted and dynamic contrast-enhanced MR images (DCE-MRI) were acquired. Two radiologists evaluated the MR images in consensus for tumor suspicious regions (TSRs) for local recurrence. Subsequently, these TSRs were biopsied under MR-guidance and histopathologically evaluated for the presence of recurrent PCa. Descriptive statistical analysis was applied. RESULTS: Tissue sampling was successful in all patients and all TSRs. The positive predictive value on a per patient basis was 75% (15/20) and on a per TSR basis 68% (26/38). The median number of biopsies taken per patient was 3, and the duration of an MRGB session was 31 minutes. No intervention-related complications occurred. CONCLUSIONS: The combination of MRGB and diagnostic MR imaging of the prostate was a feasible technique to localize PCa recurrence after EBRT using a low number of cores in a clinically acceptable time.

1 januari 2010, Contains fulltext : 87794.pdf (publisher's version ) (Closed access), 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.

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Radboud Universiteit Nijmegen, 11 oktober 2010, Promotores : Barentsz, J.O., Boetes, C. Co-promotor : Huisman, H.J., Contains fulltext : 88818.pdf (Publisher’s version ) (Open Access)

01 februari 2010, Contains fulltext : 87401.pdf (Publisher’s version ) (Open Access), PURPOSE: Undetected cancer in repeat transrectal ultrasound guided prostate biopsies in patients with increased prostate specific antigen greater than 4 ng/ml is a considerable concern. We investigated the tumor detection rate of tumor suspicious regions on multimodal 3 Tesla magnetic resonance imaging and subsequent magnetic resonance imaging guided biopsy in 68 men with repeat negative transrectal ultrasound guided prostate biopsies. We compared results to those in a matched transrectal ultrasound guided prostate biopsy population. Also, we determined the clinical significance of detected tumors. MATERIALS AND METHODS: A total of 71 consecutive patients with prostate specific antigen greater than 4 ng/ml and 2 or greater negative transrectal ultrasound guided prostate biopsy sessions underwent multimodal 3 Tesla magnetic resonance imaging. In 68 patients this was followed by magnetic resonance imaging guided biopsy directed toward tumor suspicious regions. A matched multisession transrectal ultrasound guided prostate biopsy population from our institutional database was used for comparison. The clinical significance of detected tumors was established using accepted criteria, including prostate specific antigen, Gleason grade, stage and tumor volume. RESULTS: The tumor detection rate of multimodal 3 Tesla magnetic resonance imaging guided biopsy was 59% (40 of 68 cases) using a median of 4 cores. The tumor detection rate was significantly higher than that of transrectal ultrasound guided prostate biopsy in all patient subgroups (p <0.01) except in those with prostate specific antigen greater than 20 ng/ml, prostate volume greater than 65 cc and prostate specific antigen density greater than 0.5 ng/ml/cc, in which similar rates were achieved. Of the 40 patients with identified tumors 37 (93%) were considered highly likely to harbor clinically significant disease. CONCLUSIONS: Multimodal magnetic resonance imaging is an effective technique to localize prostate cancer

1 mei 2010, Contains fulltext : 88599.pdf (publisher's version ) (Open Access), PURPOSE: To establish a consensus in relation to case selection, conduct of therapy, and outcomes that are associated with focal therapy for men with localized prostate cancer. MATERIAL AND METHODS: Urologic surgeons, radiation oncologists, radiologists, and histopathologists from North America and Europe participated in a consensus workshop on focal therapy for prostate cancer. The consensus process was face to face within a structured meeting, in which pertinent clinical issues were raised, discussed, and agreement sought. Where no agreement was possible, this was acknowledged, and the nature of the disagreement noted. RESULTS: Candidates for focal treatment should have unilateral low- to intermediate-risk disease with clinical stage

Radboud Universiteit Nijmegen, 24 november 2010, Promotores : Boetes, C., Barentsz, J.O., Contains fulltext : 82963.pdf (publisher's version ) (Open Access)

Radboud Universiteit Nijmegen, 22 december 2010, Promotores : Barentsz, J.O., Witjes, J.A. Co-promotores : Hoogeveen, Y.L., Jager, G.J., Contains fulltext : 89677.pdf (Publisher’s version ) (Open Access)

Item does not contain fulltext, Prostate cancer is the most frequently diagnosed malignancy in the Western male population and the associated socioeconomic impact on healthcare is of great concern. Since the early 1990s, MRI has evolved into an important diagnostic imaging modality for prostate cancer patients. In this review, the applications of diagnostic imaging modalities in prostate cancer, such as transrectal ultrasound, computed tomography and MRI are described. The clinical value of these techniques in prostate cancer detection, localization, characterization, staging and active surveillance are discussed.

Contains fulltext : 81481.pdf (publisher's version ) (Closed access)

Contains fulltext : 81823.pdf (publisher's version ) (Closed access), PURPOSE: To prospectively evaluate the feasibility of magnetic resonance (MR) imaging with ferumoxtran-10 in patients with prostate cancer to depict lymph node metastases outside the routine pelvic lymph node dissection (PLND) area. MATERIALS AND METHODS: The study was approved by the institutional review boards at all four hospitals; patients provided written informed consent. Two hundred ninety-six consecutive men (mean age, 67 years; range, 47-83 years) with prostate cancer and an intermediate-to-high risk for nodal metastases (prostate-specific antigen level >10 ng/mL, Gleason score >6, or stage T3 disease) were enrolled. MR lymphography of the pelvis was performed 24 hours after intravenous drip infusion of ferumoxtran-10. Positive nodes at MR lymphography were indicated to be inside or outside the routine dissection area (RDA). On the basis of MR lymphography computed tomographic (CT)-guided biopsy, routine PLND, or MR imaging-guided minimal extended PLND was performed. RESULTS: MR lymphography findings were positive in 58 patients. Of these, 44 had histopathologic confirmation of lymph node metastases. In 18 of 44 patients (41%), MR lymphography findings showed nodes exclusively outside the RDA, which were confirmed with MR lymphography-guided extended PLND (n = 13) and CT-guided biopsy (n = 5). In another 18 patients (41%), positive nodes were located both inside and outside the RDA at MR lymphography. In these 18 patients, routine PLND was used to confirm the nodes inside the RDA (n = 11); CT-guided biopsy was used to confirm nodes outside the RDA (n = 7). In the remaining eight patients, MR lymphography findings showed only nodes inside the RDA, which was confirmed with PLND (n = 5) and CT-guided biopsy (n = 3). In 14 of the 58 patients (24%), there was no histologic confirmation. CONCLUSION: In 41% of patients with prostate cancer, nodal metastases outside the area of routine PLND were detected by using MR imaging with ferumoxtran-10.

Contains fulltext : 81708.pdf (publisher's version ) (Closed access)

Contains fulltext : 81446.pdf (Publisher’s version ) (Open Access), BACKGROUND: Contrast enhanced imaging enables powerful, non-invasive diagnostics, important for detection and staging of early prostate cancer. The uptake of contrast agent is increased in prostate cancer as compared to normal prostate tissue. To reveal the underlying physiological mechanisms, quantification of tissue components in pathology specimens may yield important information. Aim of this study was to investigate whether microvascularity is increased in prostate confined cancer (pT2). METHODS: Radical prostatectomy specimens of 26 patients were selected for organ confined peripheral zone tumors which were restricted to one side of the prostate. Microvessels were visualized by immunohistochemistry against CD31. Specimens were scanned using a computer controlled microscope and scanning stage and vessels were recognized automatically. Pseudocolor mappings were produced showing number of vascular profiles (MVD), vascular area (MVA) and perimeter (MVP) in an overview of the entire prostate transection. MVD is a common measure for vascularity, whereas MVA represents the 3D vascular volume and MVP the perfused surface area. Mean, coefficient of variation and 75th percentile of these parameters were calculated automatically in manually indicated areas, consisting of the entire tumor area and the corresponding normal area in the contra lateral side of the prostate. RESULTS: The mappings clearly indicate areas of increased vascularity in prostate transections. In tumor tissue an increase was found compared to normal tissue of 81%, 49%, and 62% for mean MVD, mean MVA and mean MVP, respectively (P < 0.001 for all comparisons). In contrast, the heterogeneity in tumor vasculature was significantly decreased as compared to normal prostate (P < 0.001). CONCLUSIONS: Characteristics of microvasculature deviated significantly in pT2 prostate tumor as compared to normal tissue.