Evaluation of a robotic technique for transrectal MRI-guided prostate biopsies

Item does not contain fulltextOBJECTIVES: To evaluate the accuracy and speed of a novel robotic technique as an aid to perform magnetic resonance image (MRI)-guided prostate biopsies on patients with cancer suspicious regions. METHODS: A pneumatic controlled MR-compatible manipulator with 5 degrees of freedom was developed in-house to guide biopsies under real-time imaging. From 13 consecutive biopsy procedures, the targeting error, biopsy error and target displacement were calculated to evaluate the accuracy. The time was recorded to evaluate manipulation and procedure time. RESULTS: The robotic and manual techniques demonstrated comparable results regarding mean targeting error (5.7 vs 5.8 mm, respectively) and mean target displacement (6.6 vs 6.0 mm, respectively). The mean biopsy error was larger (6.5 vs 4.4 mm) when using the robotic technique, although not significant. Mean procedure and manipulation time were 76 min and 6 min, respectively using the robotic technique and 61 and 8 min with the manual technique. CONCLUSIONS: Although comparable results regarding accuracy and speed were found, the extended technical effort of the robotic technique make the manual technique - currently - more suitable to perform MRI-guided biopsies. Furthermore, this study provided a better insight in displacement of the target during in vivo biopsy procedures.01 februari 201

Prolactin Receptor in Primary Hyperparathyroidism – Expression, Functionality and Clinical Correlations

<div><h3>Background</h3><p>Primary hyperparathyroidism (PHPT) is an endocrine disorder most commonly affecting women, suggesting a role for female hormones and/or their receptors in parathyroid adenomas. We here investigated the prolactin receptor (PRLr) which is associated with tumours of the breast and other organs.</p> <h3>Methodology/Principal Findings</h3><p>PRLr expression was investigated in a panel of 37 patients with sporadic parathyroid tumours and its functionality in cultured parathyroid tumour cells. In comparison with other tissues and breast cancer cells, high levels of prolactin receptor gene (<em>PRLR</em>) transcripts were demonstrated in parathyroid tissues. PRLr products of 60/70 kDa were highly expressed in all parathyroid tumours. In addition varying levels of the 80 kDa PRLr isoform, with known proliferative activity, were demonstrated. In parathyroid tumours, PRLr immunoreactivity was observed in the cytoplasm (in all cases, n = 36), cytoplasmic granulae (n = 16), the plasma membrane (n = 12) or enlarged lysosomes (n = 4). In normal parathyroid rim (n = 28), PRLr was uniformly expressed in the cytoplasm and granulae. In <em>in vitro</em> studies of short-term cultured human parathyroid tumour cells, prolactin stimulation was associated with significant transcriptional changes in JAK/STAT, RIG-I like receptor and type II interferon signalling pathways as documented by gene expression profiling. Moreover, <em>PRLR</em> gene expression in parathyroid tumours was inversely correlated with the patients’ plasma calcium levels.</p> <h3>Conclusions</h3><p>We demonstrate that the prolactin receptor is highly abundant in human parathyroid tissues and that PRLr isoforms expression and PRLr subcellular localisation are altered in parathyroid tumours. Responsiveness of PRLr to physiological levels of prolactin was observed in the form of increased PTH secretion and altered gene transcription with significant increase of RIG-I like receptor, JAK-STAT and Type II interferon signalling pathways. These data suggest a role of the prolactin receptor in parathyroid adenomas.</p> </div

Psychopathology, trauma and delinquency: subtypes of aggression and their relevance for understanding young offenders

OBJECTIVE: To examine the implications of an ontology of aggressive behavior which divides aggression into reactive, affective, defensive, impulsive (RADI) or "emotionally hot"; and planned, instrumental, predatory (PIP) or "emotionally cold." Recent epidemiological, criminological, clinical and neuroscience studies converge to support a connection between emotional and trauma related psychopathology and disturbances in the emotions, self-regulation and aggressive behavior which has important implications for diagnosis and treatment, especially for delinquent populations. METHOD: Selective review of preclinical and clinical studies in normal, clinical and delinquent populations. RESULTS: In delinquent populations we observe an increase in psychopathology, and especially trauma related psychopathology which impacts emotions and self-regulation in a manner that hotly emotionally charged acts of aggression become more likely. The identification of these disturbances can be supported by findings in cognitive neuroscience. These hot aggressive acts can be delineated from planned or emotionally cold aggression. CONCLUSION: Our findings support a typology of diagnostic labels for disruptive behaviors, such as conduct disorder and oppositional defiant disorder, as it appears that these acts of hot emotional aggression are a legitimate target for psychopharmacological and other trauma specific interventions. The identification of this subtype of disruptive behavior disorders leads to more specific clinical interventions which in turn promise to improve hitherto unimpressive treatment outcomes of delinquents and patients with disruptive behavior

Towards real-time free-hand biopsy navigation

International audiencePurpose: Performing a transrectal ultrasound (TRUS) prostate biopsy is at the heart of the current prostate cancer detection procedure. With today's 2D live ultrasound (US) imaging equipment, this task remains complex due to the poor visibility of cancerous tissue on TRUS images and the limited anatomical context available in the 2D TRUS plane. This paper presents a rigid 2D/3DUS registration method for navigated prostate biopsy. This allows continuous localization of 15 the biopsy trajectory during the procedure. Methods: We proposed an organ-based approach to achieve real-time rigid registration without the need for any probe localization device. The registration method combines image similarity and geometric proximity of detected features. Additions to our previous work include a multi-level approach and the use of a rejection rate favouring the best matches. Their aim is to increase the 20 accuracy and time performances. These modifications and their in-depth evaluation on real clinical cases and comparison to this previous work are described. We performed static and dynamic evaluations along biopsy trajectories on a very large amount of data acquired under uncontrolled routine conditions. The computed transforms are compared to a ground truth obtained either from corresponding manually detected fiducials or from an already evaluated registration method. Results: All results show that the current method outperforms its previous version, both in terms of accuracy (the average error reported here is 12 to 17% smaller depending on the experiment) and processing time (from 20 to 60 times faster compared to the previous implementation). The dynamic registration experiment demonstrates that the method can be successfully used for continuous tracking of the biopsy location w.r.t the prostate at a rate that varies between 5 and 15 30 Hz. Conclusions: This work shows that on the fly 2D/3DUS registration can be performed very efficiently on biopsy trajectories. This allows us to plan further improvements in prostate navigation and a clinical transfer

Simulated required accuracy of image registration tools for targeting high-grade cancer components with prostate biopsies

Contains fulltext : 117653.pdf (publisher's version ) (Closed access)OBJECTIVES: To estimate the required spatial alignment accuracy for correctly grading 95 \% of peripheral zone (PZ) prostate cancers using a system for multiparametric magnetic resonance (MR)-guided ultrasound (US) biopsies. METHODS: PZ prostate tumours were retrospectively annotated on multiparametric MR series using prostatectomy specimens as reference standard. Tumours were grouped based on homogeneous and heterogeneous apparent diffusion coefficient (ADC) values using an automated ADC texture analysis method. The proportion of heterogeneous tumours containing a distinct, high Gleason grade tumour focus yielding low ADC values was determined. Both overall tumour and high-grade focal volumes were calculated. All high-grade target volumes were then used in a simulated US biopsy system with adjustable accuracy to determine the hit rate. RESULTS: An ADC-determined high-grade tumour focus was found in 63 \% of the PZ prostate tumours. The focal volumes were significantly smaller than the total tumour volumes (median volume of 0.3 ml and 1.1 ml respectively). To correctly grade 95 \% of the aggressive tumour components the target registration error (TRE) should be smaller than 1.9 mm. CONCLUSIONS: To enable finding the high Gleason grade component in 95 \% of PZ prostate tumours with MR-guided US biopsies, a technical registration accuracy of 1.9 mm is required. KEY POINTS : • MRI can identify foci of prostatic cancer with reduced apparent diffusion coefficients • Sixty-three per cent of prostatic peripheral zone tumours contain high-grade tumour low ADC foci • The median volume of such foci is 0.3 ml • Biopsy targets are significantly smaller than whole tumour volumes • Simulated registration accuracy is 1.9 mm for correctly grading 95 \% of tumours