Anja Weidner

Investigation of prostate cancer using diffusion-weighted intravoxel incoherent motion imaging.

PURPOSE The objective of this work was to evaluate the diagnostic performance of the intravoxel incoherent motion (IVIM) model to differentiate between healthy and malignant prostate tissue. MATERIALS AND METHODS Regions of interest were drawn in healthy and cancerous tissue of 13 patients with histologically proven prostate carcinoma and fitted to a monoexponential model [yielding the apparent diffusion coefficient (ADC)] and the IVIM signal equation (yielding the perfusion fraction f, the diffusion constant D and the pseudodiffusion coefficient of perfusion D⁎). Parameter maps were calculated for all parameters. RESULTS The ADC, D and f were significantly (P<.005) lowered in cancerous tissue (1.01±0.22 μm(2)/ms, 0.84±0.19 μm(2)/ms and 14.27±7.10%, respectively) compared to benign tissue (1.49±0.17 μm(2)/ms, 1.21±0.22 μm(2)/ms and 21.25±8.32%, respectively). Parameter maps of D and f allowed for a delineation of the tumor, but showed higher variations compared to the ADC map. CONCLUSION Apparent diffusion coefficient maps provide better diagnostic performance than IVIM maps for tumor detection. However, the results suggest that the reduction of the ADC in prostate cancer stems not only from changes in cellularity but also from perfusion effects. IVIM imaging might hold promise for the diagnosis of other prostatic lesions.

Diagnostic accuracy of 18F choline PET/CT using time-of-flight reconstruction algorithm in prostate cancer patients with biochemical recurrence.

Purpose Image quality (IQ) of PET in voluminous body regions can be limited, which impairs the assessment of small metastatic lesions. Time-of-flight (TOF) reconstruction algorithm may deliver an increase of spatial resolution. The purpose of this study was to evaluate the impact of TOF on IQ, lesion detection rate, lesion volume (V) and SUVmax in 18F choline PET/CT of prostate cancer patients with biochemical recurrence compared to standard PET/CT reconstruction (standard). Patients and Materials During a period of 9 months, 32 patients with prostate cancer (mean [SD] age, 71 [7.8] years) and biochemical recurrence were included in this prospective institutional review board–approved study. Each patient underwent a state-of-the-art 3-dimensional 18F choline PET/CT. A total of 76 lesions were assessed by 2 board-certified nuclear medicine physicians and a third-year resident. Lesion volume and SUVmax of local recurrence, lymph nodes, and organ metastases were compared between TOF and standard. Image quality and lesion demarcation were rated according to a 5-point Likert-type scale. Interobserver agreement was assessed. Results Eight additional lesions were detected using TOF (SUVmax, 3.64 [0.95]; V, 0.58 cm3 [0.50]). Image quality was reduced (IQ standard, 1.28; TOF, 1.77; P < 0.01) in calculated TOF images, although quality of lesion demarcation was improved (lesion demarcation: standard, 1.66; TOF, 1.26; P < 0.01). SUVmax was significantly increased in TOF images (SUVmax standard, 6.9 [4.1]; TOF, 8.1 [4.1]; P < 0.01), whereas V did not show significant differences (V standard, 5.3 [10.4] cm3; TOF, 5.4 [10.3] cm3; P = 0.41). Interobserver agreement was good for combined ratings (1 + 2 and 3 + 4). Conclusions Application of TOF seems to be of additional value to detect small metastatic lesions in patients with prostate cancer and biochemical recurrence, which may have further clinical implications for secondary treatment.

Interscanner comparison of dynamic contrast-enhanced MRI in prostate cancer: 1.5 versus 3 T MRI.

PurposeThe aim of the study was the comparison of the diagnostic potential of dynamic contrast-enhanced magnetic resonance imaging to differentiate between prostate carcinoma and normal prostate tissue as well as prostatitis at 2 different field strengths: 1.5 versus 3 T. MethodsSixty-six patients with biopsy and/or prostatectomy of the prostate were included in the study. Magnetic resonance imaging was performed at 1.5 T in 20 patients with biopsy-proven prostate cancer (PC) and in 8 patients with prostatitis; at 3 T, we analyzed 27 patients with prostatectomy-proven PC and 11 patients with prostatitis. All examinations were performed using a combined body and endorectal coil protocol and a 2-dimensional TurboFLASH T1-weighted gradient echo sequence to calculate plasma flow (PF) and mean transit time (MTT) values. A total of 28 of 38 areas of normal prostate tissue, 20 of 27 areas of PC, and 8 of 11 prostatitis were analyzed at 1.5 or 3T. For the normalization, we calculated PC/normal and prostatitis/normal tissue ratios of PF and MTT for each patient. ResultsProstate cancer showed higher PF (P < 0.0001) and shorter MTT (P < 0.0001) at 3 T and at 1.5 T (P < 0.0001 for PF and P = 0.0016 for MTT) compared with the normal tissue. In comparison with the normal tissue, prostatitis had a statistically significant higher PF at 1.5 T (P = 0.0156) but not at 3 T (P = 0.17) and no significantly shorter MTT values both at 3 (P = 0.15) and 1.5 T (P = 0.25). Sensitivity and specificity for differentiating PC from prostatitis with PF were 46% and 88% at 1.5 T (cutoff ratio, 2.3) and 89% and 73% at 3 T (cutoff ratio, 1.2), respectively. Sensitivity and specificity for MTT were 77% and 100% at 1.5 T (cutoff ratio, 0.7) and 70% and 100% at 3 T (cutoff ratio, 0.6), respectively. We found no significant relationship between the Gleason score and PF/MTT (P = 0.17/0.11 for 1.5 T and P = 0.23/0.18 for 3 T). ConclusionsThe differentiation between PC and the normal tissue is possible with both field strengths. Prostate cancer can be better distinguished from prostatitis at 3 T compared with 1.5 T. The differentiation between prostatitis and the normal tissue is limited at both field strengths.

Value of multiparametric prostate MRI of the peripheral zone

RATIONALE AND OBJECTIVES MRI of the prostate offers the possibility to localize and stage prostate cancer and may improve detection of disease. Currently, T2-weighted images and spectroscopy are the most commonly used MRI techniques. To assess the value of prostate MRI and its different modalities in the process of diagnosis, the currently available MRI techniques were compared. MATERIALS AND METHODS 16 patients were examined on a 1.5 T MR system. All patients underwent the same MR protocol using an endorectal coil: T2-weighted triplanar turbo-spin-echo (TSE), axial echo-planar diffusion-weighted imaging (DWI), 3D chemical-shift imaging MR spectroscopy (MRS) and axial dynamic-contrast-enhanced TurboFLASH (DCE). Parametric maps of the choline+creatine/citrate ratio (CC-CR), apparent diffusion coefficient (ADC) and plasma flow/mean transit time (PF/MTT) were calculated. Additionally, average time for reading and scanning were evaluated. As reference, biopsy results were used. RESULTS Sensitivity/specificity were 50.0-85.7%/44.4-72.2% for the T2 weighted images, 78.6-100.0%/38.9-55.6% for the ADC maps, 71.4-85.7%/44.4-55.6% for the PF/MTT maps and 64.3-78.6%/50.0-77.8% for the CC-CR. Average scan and reading time were 8:46/1:54 min for T2, 1:28/3:17 min for DWI, 8:41/2:12 min for DCE and 11:36/3:47 for spectroscopy. CONCLUSION We found no significant differences in accuracy between the modalities. We observed DWI to be advantageous in examination and reading compared to DCE and MRS, therefore it might be the preferred modality when a shortened protocol is needed.

Ferumoxtran-10 MR lymphography for target definition and follow-up in a patient undergoing image-guided, dose-escalated radiotherapy of lymph nodes upon PSA relapse

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, doseescalated 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.ZusammenfassungZiel:Die Evaluation des Lymphknotenstatus bei Patienten mit Prostatakarzinom ist für eine erfolgreiche Strahlentherapie notwendig. Eine Möglichkeit zur Erkennung von Lymphknotenmetastasen stellt die Magnetresonanztomographie der Lymphknoten mittels Ferumoxtran-10 dar. Wir stellen erste Erfahrungen mit Ferumoxtran-10 als Grundlage für eine bildgeführte Strahlentherapie der Lymphabflusswege vor.Patienten und Methodik:Ein Patient mit Verdacht auf Lymphknotenmetastasen nach radikaler Prostatektomie wurde mittels Magnetresonanztomographie der Lymphknoten mit dem lymphknotenspezifischen Kontrastmittel Ferumoxtran-10 untersucht (Tabelle 1). Eine Intensitäts-modulierte Strahlentherapie wurde mit folgender Gesamtdosis durchgeführt: 44 Gy gesamte Lymphabflusswege, 60 Gy metastatische Lymphknoten, 71 Gy Prostataloge und 75 Gy Anastomosenregion (Abbildung 2). 8 Wochen nach Beendigung der Strahlentherapie wurde eine erneute Magnetresonanztomographie der Lymphknoten zur Kontrolle durchgeführt.Ergebnisse:In der ersten Magnetresonanztomographie der Lymphkntoten zeigten sich 5 metastatische Lymphknoten iliakal (Abbildung 1a und 1b). In der Kontrolluntersuchung 8 Wochen nach Therapie konnten keine verdächtigen Lymphknoten mehr nachgewiesen werden (Abbildung 3a und 3b, Tabelle 2). Der PSA-Wert (prostataspezifisches Antigen) sank von 2,06 ng/ml vor Therapie auf 0,02 ng/ml 2 Wochen nach Therapie und war 8 Monate nach Therapie nicht mehr messbar.Schlussfolgerung:Die Intensitätsmodulierte Strahlentherapie mit gesteigerter Dosis auf Grundlage des Lymphknotenstaging mittels Ferumoxtran-10 führte zu einer Eliminierung metastatischer Lymphknoten und einem Absinken des PSA-Wertes.

Small Field-of-view single-shot EPI-DWI of the prostate: Evaluation of spatially-tailored two-dimensional radiofrequency excitation pulses

PURPOSE Spatially-tailored (RF) excitation pulses in echo-planar imaging (EPI), combined with a decreased FOV in the phase-encoding direction, enable a reduction of k-space acquisition lines, which shortens the echo train length (ETL) and reduces susceptibility artifacts. The purpose of this study was to evaluate the image quality of a zoomed EPI (z-EPI) sequence in diffusion-weighted imaging (DWI) of the prostate in comparison to a conventional single-shot EPI using single-channel (c-EPI1) and multi-channel (c-EPI2) RF excitation, with and without use of an endorectal coil. MATERIALS AND METHODS 33 consecutive patients (mean age: 61 +/- 9 years; mean PSA: 8.67±6.23 ng/ml) with examinations between 10/2012 and 02/2014 were analyzed in this retrospective study. In 26 of 33 patients the initial multiparametric (mp)-MRI was performed on a whole-body 3T scanner (Magnetom Trio, Siemens, Erlangen, Germany) using an endorectal coil (c (conventional)-EPI1). Zoomed-EPI (Z-EPI) examinations of these patients and a complete mp-MRI protocol including c-EPI2 of 7 additional patients were carried out on another 3T wb MR scanner with two-channel dynamic parallel transmit capability (Magnetom Skyra with TimTX TrueShape, Siemens). For z-EPI, the one-dimensional spatially selective RF excitation pulse was replaced by a two-dimensional RF pulse. Degree of image blur and susceptibility artifacts (0=not present to 3= non-diagnostic), maximum image distortion (mm), apparent diffusion coefficient (ADC) values, as well as overall scan preference were evaluated. SNR maps were generated to compare c-EPI2 and z-EPI. RESULTS Overall image quality of z-EPI was preferred by both readers in all examinations with a single exception. Susceptibility artifacts were rated significantly lower on z-EPI compared to both other methods (z-EPI vs c-EPI1: p<0.01; z-EPI vs c-EPI2: p<0.01) as well as image blur (z-EPI vs c-EPI1: p<0.01; z-EPI vs c-EPI2: p<0.01). Image distortion was not statistically significantly reduced with z-EPI (z-EPI vs c-EPI1: p=0.12; z-EPI vs c-EPI2: p=0.42). Interobserver agreement for ratings of susceptibility artifacts, image blur and overall scan preference was good. SNR was higher for z-EPI than for c-EPI1 (n=1). CONCLUSION Z-EPI leads to significant improvements in image quality and artifacts as well as image blur reduction improving prostate DWI and enabling accurate fusion with conventional sequences. The improved fusion could lead to advantages in the field of MRI-guided biopsy suspicous lesions and performance of locally ablative procedures for prostate cancer.

Multiparametrische MRT der Prostata zum Therapiemonitoring nach Strahlentherapie

CLINICAL/METHODICAL ISSUE Radiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options. STANDARD RADIOLOGICAL METHODS For detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice. PERFORMANCE Good results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date. PRACTICAL RECOMMENDATIONS As the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.ZusammenfassungKlinisches/methodisches ProblemFür Patienten mit Prostatakarzinom stellt die Radiatio eine potenziell kurative lokale Therapieoption dar. Im Rahmen der Nachsorge nach lokal kurativ intendierter Therapie wird aktuell der Verlauf des PSA-Werts (PSA prostataspezifisches Antigen) kontrolliert, der Einsatz bildgebender Verfahren wird lediglich bei symptomatischen Patienten und/oder zur Planung einer Salvagetherapie empfohlen.Radiologische StandardverfahrenDie MRT der Prostata stellt derzeit die Methode der Wahl zur lokalen Rezidivdiagnostik dar.LeistungsfähigkeitInsbesondere in Verbindung mit funktionellen Untersuchungstechniken zeigen Studien gute Ergebnisse in der Primärdiagnostik. Zum Einsatz der MRT der Prostata in der Rezidivsituation wurden bisher nur wenige Studien mit heterogenem Studiendesign publiziert. Auch die in der MRT nach Bestrahlung sichtbaren Veränderungen in den unterschiedlichen Modalitäten sind noch wenig evaluiert.Empfehlung für die PraxisDa die ersten Studienergebnisse auch bei Patienten nach Radiatio viel versprechend sind, sollte bei unklarem PSA-Anstieg und vorhandener Therapieoption eine MRT der Prostata zur Klärung der lokalen Situation in Betracht gezogen werden.AbstractClinical/methodical issueRadiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options.Standard radiological methodsFor detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice.PerformanceGood results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date.Practical recommendationsAs the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.

Color-coded visualization of magnetic resonance imaging multiparametric maps

Multiparametric magnetic resonance imaging (mpMRI) data are emergingly used in the clinic e.g. for the diagnosis of prostate cancer. In contrast to conventional MR imaging data, multiparametric data typically include functional measurements such as diffusion and perfusion imaging sequences. Conventionally, these measurements are visualized with a one-dimensional color scale, allowing only for one-dimensional information to be encoded. Yet, human perception places visual information in a three-dimensional color space. In theory, each dimension of this space can be utilized to encode visual information. We addressed this issue and developed a new method for tri-variate color-coded visualization of mpMRI data sets. We showed the usefulness of our method in a preclinical and in a clinical setting: In imaging data of a rat model of acute kidney injury, the method yielded characteristic visual patterns. In a clinical data set of N = 13 prostate cancer mpMRI data, we assessed diagnostic performance in a blinded study with N = 5 observers. Compared to conventional radiological evaluation, color-coded visualization was comparable in terms of positive and negative predictive values. Thus, we showed that human observers can successfully make use of the novel method. This method can be broadly applied to visualize different types of multivariate MRI data.

[Multiparametric prostate MRI for follow-up monitoring after radiation therapy].

CLINICAL/METHODICAL ISSUE Radiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options. STANDARD RADIOLOGICAL METHODS For detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice. PERFORMANCE Good results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date. PRACTICAL RECOMMENDATIONS As the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.ZusammenfassungKlinisches/methodisches ProblemFür Patienten mit Prostatakarzinom stellt die Radiatio eine potenziell kurative lokale Therapieoption dar. Im Rahmen der Nachsorge nach lokal kurativ intendierter Therapie wird aktuell der Verlauf des PSA-Werts (PSA prostataspezifisches Antigen) kontrolliert, der Einsatz bildgebender Verfahren wird lediglich bei symptomatischen Patienten und/oder zur Planung einer Salvagetherapie empfohlen.Radiologische StandardverfahrenDie MRT der Prostata stellt derzeit die Methode der Wahl zur lokalen Rezidivdiagnostik dar.LeistungsfähigkeitInsbesondere in Verbindung mit funktionellen Untersuchungstechniken zeigen Studien gute Ergebnisse in der Primärdiagnostik. Zum Einsatz der MRT der Prostata in der Rezidivsituation wurden bisher nur wenige Studien mit heterogenem Studiendesign publiziert. Auch die in der MRT nach Bestrahlung sichtbaren Veränderungen in den unterschiedlichen Modalitäten sind noch wenig evaluiert.Empfehlung für die PraxisDa die ersten Studienergebnisse auch bei Patienten nach Radiatio viel versprechend sind, sollte bei unklarem PSA-Anstieg und vorhandener Therapieoption eine MRT der Prostata zur Klärung der lokalen Situation in Betracht gezogen werden.AbstractClinical/methodical issueRadiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options.Standard radiological methodsFor detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice.PerformanceGood results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date.Practical recommendationsAs the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.

Multiparametrische MRT der Prostata zum Therapiemonitoring nach Strahlentherapie@@@Multiparametric prostate MRI for follow-up monitoring after radiation therapy

CLINICAL/METHODICAL ISSUE Radiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options. STANDARD RADIOLOGICAL METHODS For detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice. PERFORMANCE Good results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date. PRACTICAL RECOMMENDATIONS As the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.ZusammenfassungKlinisches/methodisches ProblemFür Patienten mit Prostatakarzinom stellt die Radiatio eine potenziell kurative lokale Therapieoption dar. Im Rahmen der Nachsorge nach lokal kurativ intendierter Therapie wird aktuell der Verlauf des PSA-Werts (PSA prostataspezifisches Antigen) kontrolliert, der Einsatz bildgebender Verfahren wird lediglich bei symptomatischen Patienten und/oder zur Planung einer Salvagetherapie empfohlen.Radiologische StandardverfahrenDie MRT der Prostata stellt derzeit die Methode der Wahl zur lokalen Rezidivdiagnostik dar.LeistungsfähigkeitInsbesondere in Verbindung mit funktionellen Untersuchungstechniken zeigen Studien gute Ergebnisse in der Primärdiagnostik. Zum Einsatz der MRT der Prostata in der Rezidivsituation wurden bisher nur wenige Studien mit heterogenem Studiendesign publiziert. Auch die in der MRT nach Bestrahlung sichtbaren Veränderungen in den unterschiedlichen Modalitäten sind noch wenig evaluiert.Empfehlung für die PraxisDa die ersten Studienergebnisse auch bei Patienten nach Radiatio viel versprechend sind, sollte bei unklarem PSA-Anstieg und vorhandener Therapieoption eine MRT der Prostata zur Klärung der lokalen Situation in Betracht gezogen werden.AbstractClinical/methodical issueRadiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options.Standard radiological methodsFor detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice.PerformanceGood results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date.Practical recommendationsAs the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA.