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Objective:: With increasing incorporation of MRI in radiotherapy, we investigate two MRI sequences for prostate delineation in radiographer-led image guidance., Methods:: Five therapeutic radiographers contoured the prostate individually on CT, T 2 weighted (T 2 W) and T 2 * weighted (T 2 *W) imaging for 10 patients. Contours were analysed with Monaco ADMIRE (research v. 2.0) to assess interobserver variability and accuracy by comparison with a gold standard clinician contour. Observers recorded time taken for contouring and scored image quality and confidence in contouring., Results:: There is good agreement when comparing radiographer contours to the gold-standard for all three imaging types with Dice similarity co-efficient 0.91-0.94, Cohen's κ 0.85-0.91, Hausdorff distance 4.6-7.6 mm and mean distance between contours 0.9-1.2 mm. In addition, there is good concordance between radiographers across all imaging modalities. Both T 2 W and T 2 *W MRI show reduced interobserver variability and improved accuracy compared to CT, this was statistically significant for T 2 *W imaging compared to CT across all four comparison metrics. Comparing MRI sequences reveals significantly reduced interobserver variability and significantly improved accuracy on T 2 *W compared to T 2 W MRI for DSC and Cohen's κ. Both MRI sequences scored significantly higher compared to CT for image quality and confidence in contouring, particularly T 2 *W. This was also reflected in the shorter time for contouring, measuring 15.4, 9.6 and 9.8 min for CT, T 2 W and T 2 *W MRI respectively. Conclusion: Therapeutic radiographer prostate contours are more accurate, show less interobserver variability and are more confidently and quickly outlined on MRI compared to CT, particularly using T 2 *W MRI. Advances in knowledge: Our work is relevant for MRI sequence choice and development of the roles of the interprofessional team in the advancement of MRI-guided radiotherapy.

Background and Purpose: Intraprostatic fiducial markers (FM) improve the accuracy of radiotherapy (RT) delivery. Here we assess geometric integrity and contouring consistency using a T2*-weighted (T2*W) sequence alone, which allows visualization of the FM., Material and Methods: Ten patients scanned within the Prostate Advances in Comparative Evidence (PACE) trial (NCT01584258) had prostate images acquired with computed tomography (CT) and Magnetic Resonance (MR) Imaging: T2-weighted (T2W) and T2*W sequences. The prostate was contoured independently on each imaging dataset by three clinicians. Interobserver variability was assessed using comparison indices with Monaco ADMIRE (research version 2.0, Elekta AB) and examined for statistical differences between imaging sets. CT and MR images of two test objects were acquired to assess geometric distortion and accuracy of marker positioning. The first was a linear test object comprising straight tubes in three orthogonal directions, the second was a smaller test object with markers suspended in gel., Results: Interobserver variability for prostate contouring was lower for both T2W and T2*W compared to CT, this was statistically significant when comparing CT and T2*W images. All markers are visible in T2*W images with 29/30 correctly identified, only 3/30 are visible in T2W images. Assessment of geometric distortion revealed in-plane displacements were under 0.375 mm in MRI, and through plane displacements could not be detected. The signal loss in the MR images is symmetric in relation to the true marker position shown in CT images., Conclusion: Prostate T2*W images are geometrically accurate, and yield consistent prostate contours. This single sequence can be used to identify FM and for prostate delineation in a mixed MR-CT workflow., (© 2019 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.)

Radiation therapy to the prostate involves increasingly sophisticated delivery techniques and changing fractionation schedules. With a low estimated α/β ratio, a larger dose per fraction would be beneficial, with moderate fractionation schedules rapidly becoming a standard of care. The integration of a magnetic resonance imaging (MRI) scanner and linear accelerator allows for accurate soft tissue tracking with the capacity to replan for the anatomy of the day. Extreme hypofractionation schedules become a possibility using the potentially automated steps of autosegmentation, MRI-only workflow, and real-time adaptive planning. The present report reviews the steps involved in hypofractionated adaptive MRI-guided prostate radiation therapy and addresses the challenges for implementation., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Attention is vital for optimal behavioural performance in every-day life. Mindfulness meditation has been shown to enhance attention. However, the components of attention altered by meditation and the related neural activities are underexplored. In particular, the contributions of inhibitory processes and sustained attention are not well understood. To address these points, 34 meditators were compared to 28 age and gender matched controls during electroencephalography (EEG) recordings of neural activity during a Go/Nogo response inhibition task. This task generates a P3 event related potential, which is related to response inhibition processes in Nogo trials, and attention processes across both trial types. Compared with controls, meditators were more accurate at responding to Go and Nogo trials. Meditators showed a more frontally distributed P3 to both Go and Nogo trials, suggesting more frontal involvement in sustained attention rather than activity specific to response inhibition. Unexpectedly, meditators also showed increased positivity over the right parietal cortex prior to visual information reaching the occipital cortex (during the pre-C1 window). Both results were positively related to increased accuracy across both groups. The results suggest that meditators show altered engagement of neural regions related to attention, including both higher order processes generated by frontal regions, and sensory anticipation processes generated by poster regions. This activity may reflect an increased capacity to modulate a range of neural processes in order to meet task requirements. This increased capacity may underlie the improved attentional function observed in mindfulness meditators. [ABSTRACT FROM AUTHOR]

IMPORTANCE Substance use disorders (SUDs) are among the most common sequelae of childhood maltreatment, yet the independent contributions of SUDs and childhood maltreatment to neurobiological changes and the effect of the latter on relapse risk (a critical variable in addiction treatment) are relatively unknown. OBJECTIVES To identify structural neural characteristics independently associated with childhood maltreatment (CM; a common type of childhood adversity), comparing a sample with SUD with a demographically comparable control sample, and to examine the relationship between CM-related structural brain changes and subsequent relapse. DESIGN. SETTING. AND PARTICIPANTS Structural magnetic resonance imaging study comparing 79 treatment-engaged participants with SUD in acute remission in inpatient treatment at a community mental health center vs 98 healthy control participants at an outpatient research center at an academic medical center. Both groups included individuals with a range of CM experiences. Participants with SUD were followed up prospectively for 90 days to assess relapse and relapse severity. INTERVENTION Standard 12-step, recovery-based, inpatient addiction treatment for all participants with SUD. MAIN OUTCOMES AND MEASURES Gray matter volume (GMV), subsequent substance use relapse, days to relapse, and severity of relapse. RESULTS Controlling for SUD and psychiatric comorbidity, CM (dichotomously classified) was uniquely associated with lower GMV across all participants in the left hippocampus (cornu ammonis 1-3, dentate gyrus), parahippocampus (presubiculum, parasubiculum, prosubiculum, subiculum, and entorhinal cortex), and anterior fusiform gyrus (corrected P < .05; uncorrected P = .001). Among the sample with SUD, CM prospectively predicted a shorter relapse to use of any drug (P = .048), while CM-related GMV reductions predicted severity of substance use relapse (P = .04). CONCLUSIONS AND RELEVANCE Findings indicate that CM was related to decreased GMV in limbic regions, which in turn predicted increased risk of relapse in SUD. These results suggest that CM may significantly affect the course of SUD treatment outcomes and that SUD treatment planning may benefit from identifying and addressing CM. [ABSTRACT FROM AUTHOR]

Although amnestic mild cognitive impairment (aMCI; often considered a prodromal phase of Alzheimer's disease, AD) is most recognized by its implications for decline in memory function, research suggests that deficits in attention are present early in aMCI and may be predictive of progression to AD. The present study used functional magnetic resonance imaging to examine differences in the brain during the attention network test between 8 individuals with aMCI and 8 neurologically healthy, demographically matched controls. While there were no significant behavioral differences between groups for the alerting and orienting functions, patients with aMCI showed more activity in neural regions typically associated with the networks subserving these functions (e.g., temporoparietal junction and posterior parietal regions, respectively). More importantly, there were both behavioral (i.e., greater conflict effect) and corresponding neural deficits in executive control (e.g., less activation in the prefrontal and anterior cingulate cortices). Although based on a small number of patients, our findings suggest that deficits of attention, especially the executive control of attention, may significantly contribute to the behavioral and cognitive deficits of aMCI. [ABSTRACT FROM AUTHOR]

Although possible sources and functions of the resting-state networks (RSNs) of the brain have been proposed, most evidence relies on circular logic and reverse inference. We propose that autonomic arousal provides an objective index of psychophysiological states during rest that may also function as a driving source of the activity and connectivity of RSNs. Recording blood oxygenation level-dependent (BOLD) signal using functional magnetic resonance imaging and skin conductance simultaneously during rest in human subjects, we found that the spontaneous fluctuations of BOLD signals in key nodes of RSNs are associated with changes in nonspecific skin conduc-tance response, a sensitive psychophysiological index of autonomic arousal. Our findings provide evidence of an important role for the autonomic nervous system to the spontaneous activity of the brain during "rest." [ABSTRACT FROM AUTHOR]

Study Type - Diagnostic (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? This article reviews what is currently known about diffusion weighted MRI (DW-MRI) in prostate cancer. This mini-review concisely summarises, for clinical managing patients with prostate cancer, the clinical utility of diffusion weighted MRI. OBJECTIVE • To review the clinical utility of diffusion-weighted magnetic resonance imaging (DW-MRI) in patients with prostate cancer. MATERIAL AND METHODS • The current literature on prostate cancer and DW-MRI was reviewed. RESULTS • DW-MRI can be readily acquired on a modern scanner with a short image acquisition time and no need for i.v. contrast medium. • The image contrast is based on the diffusion of water molecules and thus reflects tissue cellularity. • There is increasing evidence that DW- MRI improves the sensitivity and specificity of prostate cancer detection as well as the identification of tumour aggressiveness. • DW-MRI is also showing substantial promise as a response biomarker for both local and metastatic disease CONCLUSIONS • DW-MRI is proving to be a useful adjunct to conventional T2-weighted MRI sequences. • The eventual role of DW-MRI in combination with other MRI techniques for multiparametric assessment of prostate cancer needs to be defined further. [ABSTRACT FROM AUTHOR]

The article reports on the validation of an indirect vasculature imaging method that quantifies the measurement of biomarkers which include blood volume, vessel density and size index. It compares the results to histologic vessel and ex vivo micro-computed tomography angiography measurements. It examines the sensitivity of the vascular parameters in magnetic resonance imaging and the detection of the effects of antiangiogenic therapies on blood volume.

The challenge of managing localized prostate cancer is to distinguish patients with clinically relevant cancers, who may benefit from radical treatment, from the remainder who do not need any intervention. Active surveillance with selective radial intervention is a management strategy that offers patients the hope of avoiding "unnecessary" treatment without detriment to their long-term survival. Here we discuss the rationale for active surveillance, and the early results. There is no consensus on the optimum active surveillance protocol, with uncertainty regarding the interpretation of PSA kinetics, repeat biopsy results and prostate imaging. In the future, it is likely that molecular markers will revolutionize our ability to select patients who will benefit from definitive treatment. In the meantime, active surveillance provides an attractive way of reducing over treatment. [ABSTRACT FROM AUTHOR]

Dose-escalated radiation therapy is associated with better biochemical control at the expense of toxicity. Stereotactic body radiation therapy (SBRT) with dose escalation to the dominant intraprostatic lesion (DIL) provides a logical approach to improve outcomes in high-risk disease while limiting toxicity. This study evaluated the toxicity and quality of life (QoL) with CyberKnife-based SBRT and simultaneous integrated boost in localized prostate cancer. Eligible participants included newly diagnosed, biopsy-proven unfavorable intermediate- to high-risk localized prostate cancer (at least 1 of the following: Gleason ≥4+3, magnetic resonance imaging(MRI)–defined T3a N0, prostate-specific antigen ≥20) with up to 2 MRI–identified DILs. Participants received 36.25 Gy in 5 fractions on alternative days with a simultaneous boost to DIL up to 47.5 Gy as allowed by organ-at-risk constraints delivered by CyberKnife. All participants received androgen deprivation therapy. The primary outcome measure was acute grade 2+ genitourinary toxicity. Acute and late genitourinary and gastrointestinal toxicity using Radiation Therapy Oncology Group scoring, biochemical parameters, International Prostate Symptom Score, International Index of Erectile Function 5, and EQ-5D QoL outcomes were assessed. Between 2013 and 2023, 20 participants were enrolled with a median follow-up of 30 months. The median D95 dose to DIL was 47.43 Gy. Cumulative acute grade 2+ genitourinary and gastrointestinal toxicity were 25% and 30%, respectively. One patient developed acute grade 3 genitourinary toxicity (5%). There is no late grade 3 genitourinary or gastrointestinal toxicity to date. International Prostate Symptom Score and urinary QoL scores recovered to baseline by 6 months. Patient-reported outcomes showed no significant change in EQ-5D QoL scores at 12 weeks and 1 year. There are no cases of biochemical relapse reported to date. CyberKnife SBRT-delivered dose of 36.25 Gy to the prostate with a simultaneous integrated boost up to 47.5 Gy is well tolerated. Acute and late genitourinary and gastrointestinal toxicity rates are comparable to other contemporary SBRT trials and series with focal boost. [ABSTRACT FROM AUTHOR]

Mapping the neurobiology of meditation has been bolstered by functional MRI (fMRI) research, with advancements in ultra-high field 7 Tesla fMRI further enhancing signal quality and neuroanatomical resolution. Here, we utilize 7 Tesla fMRI to examine the neural substrates of meditation and replicate existing widespread findings, after accounting for relevant physiological confounds. In this feasibility study, we scanned 10 beginner meditators (N = 10) while they either attended to breathing (focused attention meditation) or engaged in restful thinking (non-focused rest). We also measured and adjusted the fMRI signal for key physiological differences between meditation and rest. Finally, we explored changes in state mindfulness, state anxiety and focused attention attributes for up to 2 weeks following the single fMRI meditation session. Group-level task fMRI analyses revealed significant reductions in activity during meditation relative to rest in default-mode network hubs, i.e., antero-medial prefrontal and posterior cingulate cortices, precuneus, as well as visual and thalamic regions. These findings survived stringent statistical corrections for fluctuations in physiological responses which demonstrated significant differences (p < 0.05/n, Bonferroni controlled) between meditation and rest. Compared to baseline, State Mindfulness Scale (SMS) scores were significantly elevated (F(3,9) = 8.16, p < 0.05/n, Bonferroni controlled) following the fMRI meditation session, and were closely maintained at 2-week follow up. This pilot study establishes the feasibility and utility of investigating focused attention meditation using ultra-high field (7 Tesla) fMRI, by supporting widespread evidence that focused attention meditation attenuates default-mode activity responsible for self-referential processing. Future functional neuroimaging studies of meditation should control for physiological confounds and include behavioural assessments. • Ultra-high field 7 Tesla fMRI replicates default-mode network attenuation during meditation. • Decrease in thalamus and occipital activity as well, suggesting perceptual decoupling during meditation. • Findings significant after stringent control for physiological signals and other confounds. • Changes in state mindfulness for up to 2 weeks after MRI meditation session. • Meditation neuroimaging studies should include physiological control and behavioural assessments. [ABSTRACT FROM AUTHOR]

• MRI fusion alone does not significantly impact inter-observer variability in the delineation of prostate cancer bone metastases. • Significant improvements in inter-observer variability were seen with PET-CT fusion with planning CT. • Dual fusion with both PET-CT and MRI significantly increased delineated volumes of bone metastases and improved inter-observer variability as compared to MRI fusion and planning CT alone. The use of SBRT for the treatment of oligometastatic prostate cancer is increasing rapidly. While consensus guidelines are available for non-spinal bone metastases practice continues to vary widely. The aim of this study is to look at inter-observer variability in the contouring of prostate cancer non-spinal bone metastases with different imaging modalities. 15 metastases from 13 patients treated at our centre were selected. 4 observers independently contoured clinical target volumes (CTV) on planning CT alone, planning CT with MRI fusion, planning CT with PET-CT fusion and planning CT with both MRI and PET-CT fusion combined. The mean inter-observer agreement on each modality was compared by measuring the delineated volume, generalized conformity index (CIgen), and the distance of the centre of mass (dCOM), calculated per metastasis and imaging modality. Mean CTV volume delineated on planning CT with MRI and PET-CT fusion combined was significantly larger compared to other imaging modalities (p = 0.0001). CIgen showed marked variation between modalities with the highest agreement between planning CT + PET-CT (mean CIgen 0.55, range 0.32–0.73) and planning CT + MRI + PET-CT (mean CIgen 0.59, range 0.34–0.73). dCOM showed small variations between imaging modalities but a significantly shorter distance found on planning CT + PET-CT when compared with planning CT + PET-CT + MRI combined (p = 0.03). Highest consistency in CTV delineation between observers was seen with planning CT + PET-CT and planning CT + PET-CT + MRI combined. [ABSTRACT FROM AUTHOR]

Background In active surveillance (AS) for prostate cancer there are few data on long-term outcomes associated with novel imaging markers. Objective To determine long-term outcomes with respect to the apparent diffusion coefficient (ADC) derived from diffusion-weighted magnetic resonance imaging (DW-MRI) in a prospective AS cohort. Early results have already been published; we now present findings with long-term follow-up. Design, setting, and participants A subset of patients ( n = 86) underwent pre-enrolment DW-MRI in a prospective AS study between 2002 and 2006. Inclusion criteria were untreated prostate cancer, clinical T1/T2a/N0M0, Gleason ≤ 3 + 4, and prostate-specific antigen (PSA) <15 ng/ml. Protocol follow-up was by biopsy at 18–24 mo and then every 24 mo, with regular PSA measurement. Intervention Men underwent baseline DW-MRI in addition to standard sequences. ADC was measured from the index lesion on T2-weighted images. To avoid influencing treatment decisions, DW-MRI sequence results were not available to the AS study investigators. Outcome measurements and statistical analysis Baseline ADC was analysed with respect to time to radical treatment (TRT) and time to adverse histology (TAH). Kaplan-Meier analysis and univariate and multivariate regression analyses were performed. Results and limitations The median follow-up was 9.5 yr (interquartile range 7.9–10.0 yr). On univariate analysis, ADC below the median was associated with shorter TAH (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.17–3.89; p < 0.014) and TRT (HR 2.54, 95% CI 1.49–4.32; p < 0.001). Median TRT was 9.3 yr (95% CI 7.0–11.6 yr) for patients with ADC above the median and only 2.4 yr (95% CI 1.5–6.0 yr) for ADC below the median. For TRT, addition of ADC to a multivariate model of baseline variables resulted in a significant improvement in model fit (HR 1.33, 95% CI 1.14–1.54; p < 0.001). Receiver operating characteristic analysis for TRT revealed an area under the curve of 0.80 (95% CI 0.70–0.88). The number of variables included in the multivariate model was limited by sample size. Conclusions Long-term follow-up for this study provides strong evidence that ADC is a useful marker when selecting patients for AS. Routine DW-MRI is now being evaluated in our ongoing AS study for initial assessment and as an alternative to repeat biopsy. Patient summary Before entering a study of close monitoring for the initial management of prostate cancer, patients had a type of magnetic resonance imaging scan that looks at the movement of water within cancers. These scans may help in predicting whether patients should receive close monitoring or whether immediate treatment should be given. [ABSTRACT FROM AUTHOR]

Quantifying oxygenation in viable tumor remains a major obstacle toward a better understanding of the tumor micro-environment and improving treatment strategies. Current techniques are often complicated by tumor heterogeneity. Herein, a novel in vivo approach that combines F magnetic resonance imaging (19F-MRI) R1 mapping with diffusion-based multispectral (MS) analysis is introduced. This approach restricts the partial pressure of oxygen (pO2) measurements to viable tumor, the tissue of therapeutic interest. The technique exhibited sufficient sensitivity to detect a breathing gas challenge in a xenograft tumor model, and the hypoxic region measured by MS F-MRI was strongly correlated with histologic estimates of hypoxia. This approach was then applied to address the effects of antivascular agents on tumor oxygenation, which is a research question that is still under debate. The technique was used to monitor longitudinal pO2 changes in response to an antibody to vascular endothelial growth factor (B20.4.1.1) and a selective dual phosphoinositide 3-kinase/mammalian target of rapamycin inhibitor (GDC-0980). GDC-0980 reduced viable tumor pO2 during a 3-day treatment period, and a significant reduction was also produced by B20.4.1.1. Overall, this method provides an unprecedented view of viable tumor pO2 and contributes to a greater understanding of the effects of antivascular therapies on the tumor's microenvironment. [ABSTRACT FROM AUTHOR]