•Robotic needle positioning was more successful than freehand needle positioning.•Needles were positioned more accurately with robot-assistance.•The number of needle position adjustments, and ...therefore CT scans, was reduced.
To evaluate the performance of a novel robot for CT-guided needle positioning procedures and compare it to the freehand technique in an abdominal phantom.
One interventional radiology fellow and one experienced interventional radiologist (IR) performed twelve robot-assisted and twelve freehand needle positionings in a phantom over predetermined trajectories. The robot automatically aimed a needle-guide according to the planned trajectories, after which the clinician manually inserted the needle. Using repeated CT scans, the needle position was assessed and adjusted if the clinician deemed it necessary. Technical success, accuracy, number of position adjustments, and procedure time were measured. All outcomes were analyzed using descriptive statistics and were compared between the robot-assisted and freehand procedures using the paired t-test and Wilcoxon signed rank test.
Compared with the freehand technique, the robot system improved the number of technically successfully needle targeting (20/24 vs 14/24), with higher accuracy (mean Euclidean deviation from target center: 3.5 ± 1.8 mm vs 4.6 ± 2.1 mm, p = 0.02) and required fewer needle position adjustments (0.0 ± 0.2 steps vs 1.7 ± 0.9 steps, p < 0.001), respectively. The robot improved the needle positioning for both, the fellow and the expert IR, compared to their freehand performances, with more improvement for the fellow than for the expert IR. The procedure time was similar for the robot-assisted and freehand procedures (19.5 ± 9.2 min. vs 21.0 ± 6.9 min., p = 0.777).
CT-guided needle positioning with the robot was more successful and accurate than freehand needle positioning and required fewer needle position adjustments without prolonging the procedure.
Abstract Background Patients with elevated prostate-specific antigen (PSA) and one or more previous negative transrectal ultrasound (TRUS) biopsy sessions are subject to diagnostic uncertainty due to ...TRUS-biopsy undersampling. Magnetic resonance (MR)–guided biopsy (MRGB) has shown high prostate cancer (PCa)–detection rates in studies with limited patient numbers. Objective Determine the detection rate of (clinically significant) PCa for MRGB of cancer-suspicious regions (CSRs) on 3-T multiparametric MR imaging (MP-MRI) in patients with elevated PSA and one or more negative TRUS-biopsy sessions. Design, setting, and participants Of 844 patients who underwent 3-T MP-MRI in our referral centre between March 2008 and February 2011, 438 consecutive patients with a PSA >4.0 ng/ml and one negative TRUS-biopsy session or more were included. MRGB was performed in 265 patients. Exclusion criteria were existent PCa, endorectal coil use, and MP-MRI for indications other than cancer detection. Intervention Patients underwent MRGB of MP-MRI CSRs. Measurements (Clinically significant) MRGB cancer-detection rates were determined. Clinically significant cancer was defined by accepted (i.a. Epstein and d’Amico) criteria based on PSA, Gleason score, stage, and tumour volume. Follow-up PSA and histopathology were collected. Sensitivity analysis was performed for patients with MP-MRI CSRs without MRGB. Results and limitations In a total of 117 patients, cancer was detected with MRGB ( n = 108) or after negative MRGB ( n = 9). PCa was detected in 108 of 438 patients (25%) and in 41% (108 of 265) of MRGB patients. The majority of detected cancers (87%) were clinically significant. Clinically significant cancers were detected in seven of nine (78%) negative MRGB patients in whom PCa was detected during follow-up. Sensitivity analysis resulted in increased cancer detection (47–56%). Complications occurred in 0.2% of patients (5 of 265). Conclusions In patients with elevated PSA and one or more negative TRUS-biopsy sessions, MRGB of MP-MRI CSRs had a PCa-detection rate of 41%. The majority of detected cancers were clinically significant (87%).
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. Magnetic resonance imaging guided biopsy of tumor suspicious regions is an accurate method to detect clinically significant prostate cancer in men with repeat negative biopsies and increased prostate specific antigen.
Purpose
To investigate the ability of high field ex vivo magnetic resonance imaging (MRI) to localize prostate cancer (PCa) and to predict the margin status in fresh radical prostatectomy (RP) ...specimens using histology as the reference standard.
Materials and Methods
This Institutional Review Board (IRB)‐approved study had written informed consent. Patients with biopsy‐proved PCa and a diagnostic multiparametric 3T MRI examination of the prostate prior to undergoing RP were prospectively included. A custom‐made container provided reference between the 7T ex vivo MRI obtained from fresh RP specimens and histological slicing. On ex vivo MRI, PCa was localized and the presence of positive surgical margins was determined in a double‐reading session. These findings were compared with histological findings obtained from completely cut, whole‐mount embedded, prostate specimens.
Results
In 12 RP specimens, histopathology revealed 36 PCa lesions, of which 17 (47%) and 20 (56%) were correlated with the ex vivo MRI in the first and second reading session, respectively. Nine of 12 (75%) index lesions were localized in the first session, in the second 10 of 12 (83%). Seven and 8 lesions of 11 lesions with Gleason score >6 and >0.5 cc were localized in the first and second session, respectively. In the first session none of the four histologically positive surgical margins (sensitivity 0%) and 9 of 13 negative margins (specificity 69%) were detected. In second session the sensitivity and specificity were 25% and 88%, respectively.
Conclusion
Ex vivo MRI enabled accurate localization of PCa in fresh RP specimens, and the technique provided information on the margin status with high specificity.
Level of Evidence: 1
Technical Efficacy: Stage 1
J. Magn. Reson. Imaging 2018;47:439–448.
Bronchoscopic diagnosis of small peripheral lung lesions suspected of lung cancer remains a challenge. A successful endobronchial diagnosis comprises navigation, confirmation, and tissue acquisition. ...In all steps, 3-dimensional information is essential. Cone-beam computed tomography (CBCT) imaging can provide computed tomography information and 3-dimensional augmented fluoroscopy imaging. We assessed whether CBCT imaging can improve navigation and diagnosis of peripheral lesions by 2 clinical workflows with a cross-over design: (1) a primary CBCT and radial endobronchial ultrasound mini probe imaging-based approach and (2) a primary electromagnetic navigation (EMN) and radial endobronchial ultrasound mini probe imaging-based approach.
All patients with a peripheral lung lesion biopsy indication were eligible for study inclusion and randomly assigned to study arms. Commercially available equipment was used. The main study goals were to assess CBCT-confirmed navigation success and diagnostic accuracy. Surgery or unambiguous clinical follow-up served as the gold standard.
Eighty-seven patients with 107 lesions were included. Lesion mean longest axis size in the CBCT arm was 16.6 mm (n=47) and 14.2 mm in the EMN arm (n=40). The primary CBCT approach and primary EMN approach had 76.3% and 52.2% navigation success, respectively. Addition of EMN to the CBCT approach increased navigation success to 89.9%. Addition of CBCT imaging to the EMN approach significantly increased navigation success to 87.5% per lesion. The overall diagnostic accuracy per patient was significantly lower than the navigation success, being 72.4%.
CBCT imaging is a valuable addition to navigation bronchoscopy. Although overall navigation success was high, the diagnostic accuracy remains to be improved. Future research should focus on improving the tissue acquisition methodology.
ABSTRACTThis article reviews recent and ongoing developments in multiparametric magnetic resonance imaging (mpMRI) of the prostate. Advances in T2-weighted imaging, diffusion-weighted imaging, ...dynamic contrast-enhanced imaging, and spectroscopic imaging are described along with advances related to radiofrequency coils and imaging at high magnetic field. As mpMRI is increasingly becoming routine in various aspects of clinical prostate cancer management, its role in detection, localization, staging, assessment of aggressiveness, and active surveillance is discussed. Combined with growing clinical adoption of the techniques already at hand, continual optimization of acquisition techniques and image interpretation schemes will further strengthen the role of mpMRI as an important diagnostic test in prostate cancer management.
Abstract Purpose Accurate needle placement is crucial for successful tumor treatment using the irreversible electroporation (IRE) method. Multiple needles are inserted around the tumor, ideally in ...parallel, to achieve uniform electric field distribution. This paper presents a robot utilizing a grid system to enable multiple needles insertion while maintaining parallelism between them. Methods The robotic system has two degrees of freedom, which allow for the adjustment of the grid system to accommodate targeting lesions in various positions. The robot’s performance was evaluated by testing its accuracy across various configurations and target depth locations, as well as its ability to maintain the needle parallelism. Results The robot has dimensions of $${\phi }$$ ϕ 134 mm and a height of 46 mm, with a total weight of 295 g. The system accuracy test showed that the robot can precisely target points across different target depths and needle orientations, with an average error of $$2.71\pm 0.68$$ 2.71 ± 0.68 mm. Moreover, multiple insertions at different grid locations reveal needle orientation deviations typically below $$1^{\circ }$$ 1 ∘ . Conclusion This study presented the design and validation of a robotic grid system. The robot is capable of maintaining insertion accuracy and needle parallelism during multiple needle insertions at various robot configurations. The robot showed promising results with limited needle deviation, making it suitable for IRE procedures.
Guided by an ecological model, we tested whether teacher–child interaction quality buffered the negative associations between challenging behavior within preschool classroom contexts and language and ...literacy skills. Associations were examined for a sample of children enrolled an urban Head Start program (N = 304 children across 53 classrooms). Findings from multilevel models supported direct associations between challenging behaviors within preschool learning contexts and language outcomes. Higher instructional support was associated with higher language and literacy outcomes for all children within classrooms regardless of behavioral risk. Higher classroom organization was directly associated with higher classroom literacy skills. Emotional support moderated associations between challenging behaviors in teacher contexts and literacy outcomes. Implications for future research, policy, and practice are discussed.
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