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Biocompatible gold nanoparticles designed to absorb light at wave-lengths of high tissue transparency have been of particular interest for biomedical applications. The ability of such nanoparticles to convert absorbed near-infrared light to heat and induce highly localized hyperthermia has been shown to be highly effective for photothermal cancer therapy, resulting in cell death and tumor remission in a multitude of preclinical animal models. Here we report the initial results of a clinical trial in which laser-excited gold-silica nanoshells (GSNs) were used in combination with magnetic resonance–ultrasound fusion imaging to focally ablate low-intermediate-grade tumors within the prostate. The overall goal is to provide highly localized regional control of prostate cancer that also results in greatly reduced patient morbidity and improved functional outcomes. This pilot device study reports feasibility and safety data from 16 cases of patients diagnosed with low- or intermediate-risk localized prostate cancer. After GSN infusion and high-precision laser ablation, patients underwent multiparametric MRI of the prostate at 48 to 72 h, followed by postprocedure mpMRI/ultrasound targeted fusion biopsies at 3 and 12 mo, as well as a standard 12-core systematic biopsy at 12 mo. GSN-mediated focal laser ablation was successfully achieved in 94% (15/16) of patients, with no significant difference in International Prostate Symptom Score or Sexual Health Inventory for Men observed after treatment. This treatment protocol appears to be feasible and safe in men with low- or intermediate-risk localized prostate cancer without serious complications or deleterious changes in genitourinary function.

Background Adaptive magnetic resonance imaging‐guided radiation therapy (MRgRT) can escalate dose to tumors while minimizing dose to normal tissue. We evaluated outcomes of inoperable pancreatic cancer patients treated using MRgRT with and without dose escalation. Methods We reviewed 44 patients with inoperable pancreatic cancer treated with MRgRT. Treatments included conventional fractionation, hypofractionation, and stereotactic body radiation therapy. Patients were stratified into high‐dose (biologically effective dose [BED10] >70) and standard‐dose groups (BED10 ≤70). Overall survival (OS), freedom from local failure (FFLF) and freedom from distant failure (FFDF) were evaluated using Kaplan‐Meier method. Cox regression was performed to identify predictors of OS. Acute gastrointestinal (GI) toxicity was assessed for 6 weeks after completion of RT. Results Median follow‐up was 17 months. High‐dose patients (n = 24, 55%) had statistically significant improvement in 2‐year OS (49% vs 30%, P = 0.03) and trended towards significance for 2‐year FFLF (77% vs 57%, P = 0.15) compared to standard‐dose patients (n = 20, 45%). FFDF at 18 months in high‐dose vs standard‐dose groups was 24% vs 48%, respectively (P = 0.92). High‐dose radiation (HR: 0.44; 95% confidence interval [CI]: 0.21‐0.94; P = 0.03) and duration of induction chemotherapy (HR: 0.84; 95% CI: 0.72‐0.98; P = 0.03) were significantly correlated with OS on univariate analysis but neither factor was independently predictive on multivariate analysis. Grade 3+ GI toxicity occurred in three patients in the standard‐dose group and did not occur in the high‐dose group. Conclusions Patients treated with dose‐escalated MRgRT demonstrated improved OS. Prospective evaluation of high‐dose RT regimens with standardized treatment parameters in inoperable pancreatic cancer patients is warranted. Adaptive magnetic resonance imaging (MRI)‐guided radiation therapy (RT) is a novel method to deliver dose‐escalated RT to inoperable pancreatic tumors. Dose‐escalated adaptive MRI‐guided RT improved survival without compromising safety.

Background Cardiovascular magnetic resonance imaging (CMR) is valuable for the investigation and management of pulmonary artery hypertension (PAH), but the direct measurement of pulmonary hemodynamics by right heart catheterization is still necessary. CMR-guided right heart catheterization (CMR-RHC) combines the benefits of CMR and invasive cardiac catheterization, but its feasibility in patients with acquired PAH has not been established. The aims of this study are to: (1) demonstrate the feasibility of CMR-RHC in patients being assessed for PAH in a conventional diagnostic CMR scanner room; (2) determine the predictors of (i) procedure duration, and (ii) procedural failure or technical difficulty as determined by the adjunctive need for a guidewire. Methods Fifty patients investigated for suspected or known PH underwent CMR-RHC. Durations of separate procedural components were recorded, including time taken to pass the catheter from the femoral vein to a stable wedge position (procedure time) and total time the patient spent in the CMR department (department time). Associations between procedural failure/guidewire usage and hemodynamic/CMR measures were assessed using logistic regression. Relationships between procedure times and hemodynamic/CMR measures were evaluated using Spearman’s correlation coefficient. Results A full CMR-RHC study was successfully completed in 47 (94%) patients. CMR-conditional guidewires were used in 6 (12%) patients. Metrics associated with guidewire use/procedural failure were higher mean pulmonary artery (PA) pressures (mPAP: OR = 1.125, p  = 0.018), right heart dilatation (right ventricular (RV) end-systolic volume (RVESV): OR = 1.028, p  = 0.018), RV hypertrophy (OR = 1.050, p  = 0.0067) and RV ejection fraction (EF) (OR = 0.914, p  = 0.014). Median catheter and department times were 3.6 (2.0–7.7) minutes and 60.0 (54.0–68.5) minutes, respectively. All procedure times became significantly shorter with increasing procedural experience ( p  < 0.05). Catheterization time was also associated with PH severity (RV systolic pressure: rho = 0.46, p  = 0.0013) and increasing RV end-systolic volume (RVESV: rho = 0.41, p  = 0.0043), hypertrophy (rho = 0.43, p  = 0.0025) and dysfunction (RVEF: rho = − 0.32, p  = 0.031). Conclusions This study demonstrates that CMR-RHC using standard technology can be incorporated into routine clinical practice for the investigation of PAH. Procedural failure was rare but more likely in patients with severe PAH. Procedure time is clinically acceptable and increases with worsening PAH severity.

Background Cardiovascular magnetic resonance (CMR) fluoroscopy allows for simultaneous measurement of cardiac function, flow and chamber pressure during diagnostic heart catheterization. To date, commercial metallic guidewires were considered contraindicated during CMR fluoroscopy due to concerns over radiofrequency (RF)-induced heating. The inability to use metallic guidewires hampers catheter navigation in patients with challenging anatomy. Here we use low specific absorption rate (SAR) imaging from gradient echo spiral acquisitions and a commercial nitinol guidewire for CMR fluoroscopy right heart catheterization in patients. Methods The low-SAR imaging protocol used a reduced flip angle gradient echo acquisition (10° vs 45°) and a longer repetition time (TR) spiral readout (10 ms vs 2.98 ms). Temperature was measured in vitro in the ASTM 2182 gel phantom and post-mortem animal experiments to ensure freedom from heating with the selected guidewire (150 cm × 0.035″ angled-tip nitinol Terumo Glidewire ). Seven patients underwent CMR fluoroscopy catheterization. Time to enter each chamber (superior vena cava, main pulmonary artery, and each branch pulmonary artery) was recorded and device visibility and confidence in catheter and guidewire position were scored on a Likert-type scale. Results Negligible heating (< 0.07°C) was observed under all in vitro conditions using this guidewire and imaging approach. In patients, chamber entry was successful in 100% of attempts with a guidewire compared to 94% without a guidewire, with failures to reach the branch pulmonary arteries. Time-to-enter each chamber was similar (p=NS) for  the two approaches. The guidewire imparted useful catheter shaft conspicuity and enabled interactive modification of catheter shaft stiffness, however, the guidewire tip visibility was poor. Conclusions Under specific conditions, trained operators can apply low-SAR imaging and using a specific fully-insulated metallic nitinol guidewire (150 cm × 0.035” Terumo Glidewire ) to augment clinical CMR fluoroscopy right heart catheterization. Trial registration Clinicaltrials.gov NCT03152773 , registered May 15, 2017.

Transcatheter aortic valve replacement (TAVR) is the preferred treatment for older patients with severe aortic stenosis with outcomes influenced by age and sex. Computed tomography (CT) is the reference imaging modality for TAVR planning, while cardiovascular magnetic resonance (CMR) is an emerging alternative for this indication. The aim of this study was to evaluate the impact of age and sex on implantation success in patients undergoing CT- or CMR-guided TAVR. This was a secondary analysis of the randomized TAVR-CMR trial comparing TAVR planning by CT or CMR (NCT03831087). Patients were categorized according to the median age (82 years) and sex. Implantation success, defined using the Valve Academic Research Consortium-2 definition (absence of procedural mortality, correct positioning of a single prosthetic valve, and proper prosthetic valve performance), was compared at hospital discharge between age groups and sex for each imaging strategy. All-cause mortality at 6 months was compared between imaging strategies across age groups and sex. A total of 267 patients (median age 82 [IQR 80–85] years, 50% (133/267) female) underwent TAVR at two heart centers in Austria between September 2017 and December 2022. Implantation success did not differ significantly between imaging strategies across age and sex subgroups. For patients ≤82 years, success rates were 92.1% (58/63) (CT) vs. 94.7% (72/76) (CMR) (p=0.524), and for those >82 years, 89.4% (59/66) (CT) vs. 91.9% (57/62) (CMR) (p=0.622). Among female patients, success rates were 84.7% (50/59) (CT) vs. 93.2% (69/74) (CMR) (p=0.113), and among male patients, 95.7% (67/70) (CT) vs. 93.8% (60/64) (CMR) (p=0.610). All-cause mortality at 6 months did not differ significantly between imaging strategies across age and sex subgroups. Mortality rates for patients ≤82 and >82 years were 4.8% (3/63) vs. 5.3% (4/76) (p=0.839) and 9.1% (6/66) vs. 12.9% (8/62) (p=0.490) for CT and CMR, respectively. Similarly, female and male patients had comparable mortality rates (10.2% (6/59) vs. 8.1% (6/74), p=0.680; 4.3% (3/70) vs. 9.4% (6/64), p=0.240). In this secondary analysis of the TAVR-CMR trial, CMR-guided TAVR was associated with similar outcomes compared with CT-guided TAVR irrespective of age and sex. [Display omitted]

ObjectiveThe aim of our study was (1) to establish an in-bore targeted biopsy of suspicious prostate lesions, avoiding bowel penetration using a transgluteal approach and (2) to assess operator setup, patient comfort and safety aspects in the clinical setting for freehand real-time MR-guidance established for percutaneous procedures in an open MR-scanner.Material and methods30 patients with suspect prostate lesions were biopsied in a cylindrical 3T-MRI system using a transgluteal approach in freehand technique. One to three biopsies were sampled using continuous dynamic imaging. Size, location and visibility of the lesion, intervention time, needle artefact size, interventional complications and histopathological diagnosis were recorded.ResultsAll biopsies were technically successful. Nineteen patients showed evidence of prostate carcinoma. Cancer detection rate was 50 % in patients with previously negative TRUS-biopsy. The average intervention time was 26 min including a learning curve as the time was 13 min by the end of the study. No antibiotic prophylaxis was performed as none of the patients showed signs of infection.ConclusionsMR-guided targeted freehand biopsies of prostate lesions using a transgluteal approach are both technically feasible and time efficient in a standard closed-bore 3T-MR scanner as well as safe for the individual patient.Key Points• Open-bore freehand interventional principles were adapted to closed-bore systems.• Prostate MR-guided freehand biopsies were feasible in a clinical setting.• A transgluteal approach provides a short and simplified work flow.• An inoculation of the prostate with bowel flora is avoided.• The intervention time is comparable to the stereotactic approach.

MR imaging provides awareness for rectoprostatic hematomas as a complication in prostate biopsy. We evaluated the frequency and size of clinically silent bleeding after in-bore MRI-guided prostate biopsy according to documentation in MRI. From 2007 until 2020 in-bore MRI-guided prostate biopsy was performed in 283 consecutive patients with suspected prostate cancer. Interventional image documentation was reviewed for rectoprostatic hematomas and rectal blood collections in this retrospective observational single-center study. Correlation to patient characteristics was analyzed using a multivariable logistic regression model. 283 consecutive patients with a mean age of 66 ± 8 years were included. We diagnosed bleeding complications in 41 (14.5%) of the patients. Significant rectoprostatic hematomas were found in 24 patients. Intra-rectal blood collections were observed in 16 patients and one patient showed bleeding in the urinary bladder. The volume of rectoprostatic hematomas was determined with a median of 7.5 ml (range 2–40 ml, IQR 11.25). We found no correlation between the presence of a rectoprostatic hematoma and malignant findings, patient position in biopsy, number of cores, age, prostate volume nor PSA density (p > 0.05). Rectoprostatic hematomas and rectal blood collections are rare complications after in-bore MR-guided prostate biopsy. MR imaging provides benefits not only for lesion detection in prostate biopsy but also for the control of bleeding complications, which can be overlooked in standard TRUS biopsy. Their significance in pain, erectile dysfunction, and urinary retention remains to be investigated.

Image-guided endovascular interventions have gained increasing popularity in clinical practice, and magnetic resonance imaging (MRI) is emerging as an attractive alternative to X-ray fluoroscopy for guiding such interventions. Steering catheters by remote control under MRI guidance offers unique challenges and opportunities. In this review, the benefits and limitations of MRI-guided remote control intervention are addressed, and the tools for guiding such interventions in the magnetic environment are summarized. Designs for remote control catheter guidance include a catheter tip electromagnetic microcoil design, a ferromagnetic sphere-tipped catheter design, smart material-actuated catheters, and hydraulically actuated catheters. Remote control catheter guidance systems were compared and contrasted with respect to visualization, safety, and performance. Performance is characterized by bending angles achievable by the catheter, time to achieve bending, degree of rotation achievable, and miniaturization capacity of the design. Necessary improvements for furthering catheter design, especially for use in the MRI environment, are addressed, as are hurdles that must be overcome in order to make MRI guided endovascular procedures more accessible for regular use in clinical practice. MR-guided endovascular interventions under remote control steering are in their infancy due to issues regarding safety and reliability. Additional experimental studies are needed prior to their use in humans.

Interventional cardiovascular magnetic resonance (iCMR) might evolve as a technique to improve procedural success rates in cardiovascular interventions by combining intraprocedural guidance and simultaneous lesion imaging. The objective of the present study was to prove feasibility and estimate safety of renal sympathetic denervation guided by real-time iCMR using active tracking. Six pigs were examined in a 1.5 T MRI-System (Achieva, Philips Healthcare, Best, Netherlands) equipped with non-invasive hemodynamic control and in-room monitors displaying an interventional software platform [Interventional MRI Suite (iSuite), Philips Research, Hamburg, Germany]. MR-guided renal denervation was performed using a MR conditional non-irrigated ablation catheter with active tracking (Imricor, Burnsville, MN, USA). Real-time imaging for device guidance was performed with a TFE sequence, vessel patency was assessed with a 3D non-contrast angiography and velocity encoded imaging. Oedema of the renal artery was visualized by a high-resolution T2 SPIR sequence. Renal sympathetic denervation was feasible in all cases with survival of all animals. Non-contrast angiography displayed renal artery patency accompanied by equal flow conditions before and after the ablation in all cases as measured by velocity encoded imaging. Oedema imaging displayed a significant increase in relative signal intensity at renal artery ablations sites pre and post intervention (p < 0.05). The histologic examination revealed no signs of perforation or bleeding, while sufficient ablation lesions could be depicted. MR-guided renal sympathetic denervation using active tracking is feasible and the initial data suggest safety of this procedure. MR-guided renal sympathetic denervation offers the inherent strength of high soft tissue contrast thereby providing target information without the use of iodinated contrast agents or radiation.

Background and purpose To analyze the time course of late rectal- and urinary bladder complications after brachytherapy for cervical cancer and to compare the incidence- and prevalence rates thereof. Patients and methods A total of 225 patients were treated with external-beam radiotherapy (EBRT) and magnetic resonance imaging (MRI)-guided brachytherapy with or without chemotherapy. Late side effects were assessed prospectively using the Late Effects in Normal Tissue—Subjective, Objective, Management and Analytic (LENT/SOMA) scale. The parameters analyzed were time to onset, duration, actuarial incidence- (occurrence of new side effects during a defined time period) and prevalence rates (side effects existing at a defined time point). Results Median follow-up was 44 months. Side effects (grade 1–4) in rectum and bladder were present in 31 and 49 patients, 14 and 27 months (mean time to onset) after treatment, respectively. All rectal and 76 % of bladder side effects occurred within 3 years after radiotherapy. Mean duration of rectal events was 19 months; 81 % resolved within 3 years of their initial diagnosis. Mean duration of bladder side effects was 20 months; 61 % resolved within 3 years. The 3- and 5-year actuarial complication rates were 16 and 19 % in rectum and 18 and 28 % in bladder, respectively. The corresponding prevalence rates were 9 and 2 % (rectum) and 18 and 21 % (bladder), respectively. Conclusion Late side effects after cervical cancer radiotherapy are partially reversible, but their time course is organ-dependent. The combined presentation of incidence- and prevalence rates provides the most comprehensive information.