Examining the relationship between subtypes of rumination and non-suicidal self-injury: A meta-analytic review.

INTRODUCTION: Non-suicidal self-injury (NSSI) is a highly prevalent maladaptive behavior, often used to cope with intense negative affect. Rumination is an emotion regulation strategy that leads to fixation on and exacerbation of (typically) negative affective states. However, studies examining the relationship between rumination and NSSI have yielded mixed results, showing high degrees of heterogeneity. METHODS: The present study conducted meta-analyses (k = 50) of the association between overall rumination and NSSI, and independent meta-analyses for each of four subtypes of rumination (general, depressive, brooding, reflection rumination). Potential moderators that may influence the magnitude of these relationships were also examined. RESULTS: A small-to-moderate positive association between rumination and NSSI was found independent of rumination subtype. Moderating effects included NSSI outcome measure and study design for overall rumination and general rumination, respectively. Race was found to moderate the relationships between both brooding and depressive rumination and NSSI, though in inverse directions. An analysis of effect heterogeneity across studies suggested that undetected moderators may be present. CONCLUSION: Results of this study support the relationships between rumination subtypes and NSSI and identify factors that may impact these relationships. Continued research is needed to understand this association, particularly in more varied subtypes of rumination and cognitive-affective moderators.

A systematic review with meta-analysis of cognitive bias modification interventions for anger and aggression.

Aggression and anger are associated with interpretation and attention biases. Such biases have become treatment targets for anger and aggressive behavior in cognitive bias modification (CBM) interventions. Several studies have evaluated the efficacy of CBM for the treatment of anger and aggressive behavior, with inconsistent results. The present study meta-analytically analyzed 29 randomized controlled trial studies (N = 2334) published in EBSCOhost and PubMed between March 2013 and March 2023 assessing the efficacy of CBM for anger and/or aggression. Included studies delivered CBMs that addressed either attention biases, interpretation biases, or both. Risk of publication bias and potential moderating effects of several participant-, treatment- and study-related factors were assessed. CBM significantly outperformed control conditions in the treatment of aggression (Hedge's G = -0.23, 95% CI [-0.35, -0.11], p < .001) and anger (Hedge's G = -0.18, 95% CI [-0.28, -0.07], p = .001) independent of treatment dose, participant demographic characteristics, and study quality, though overall effects were small. Follow-up analyses demonstrated that only CBMs targeting interpretation bias were efficacious for aggression outcomes, but not when baseline aggression was accounted for. Findings suggest that CBM demonstrates efficacy for the treatment aggressive behavior and to a lesser extent, anger.

Cognition and Non-Suicidal Self-Injury: Exploring Relationships with Psychological Functions.

OBJECTIVE: Non-suicidal self-injury (NSSI) is strongly associated with difficulties in emotion regulation, but its relationships with maladaptive cognitive processes are less clear. METHOD: The current study examined relationships between self-reported NSSI (presence, number of methods, frequency, recency, duration, functions) and negative cognitive processes (rumination, worry, self-criticism, perceived burdensomeness, thwarted belongingness) among 1,357 undergraduates. Cognition variables were submitted to exploratory factor analysis (EFA), and relationships were examined between the resulting factors and NSSI history (among the full sample) and NSSI severity and functions (among those with a history of NSSI). RESULTS: The EFA derived two higher order cognitive factors: repetitive negative thinking (RNT) and negative self-perception (NSP). Both RNT and NSP were significantly higher among participants with than those without a history of NSSI. Among those with NSSI, NSP, but not RNT, was positively related to lifetime NSSI frequency and number of methods, as well as recency (presence in the past 12 months) and total duration (in years) of NSSI engagement. Moreover, RNT and NSP were positively associated with aggregate intrapersonal (but not interpersonal) functions of NSSI. The two cognitive factors demonstrated differential relationships with the individual intrapersonal NSSI functions. CONCLUSIONS: Higher order categories of cognitive risk factors may have unique relationships with functions and severity of NSSI, with possible implications for more targeted approaches to risk assessment and intervention.HighlightsNegative thinking and self-perception were higher in people who engage in NSSI.Negative self-perception was associated with greater NSSI severity.Negative thinking and self-perception had different relations to NSSI functions.

The effect of dialectical behavior therapy on anger and aggressive behavior: A systematic review with meta-analysis.

Dysregulated anger, and its common behavioral urge, aggression, pose substantial costs to public health and society. Though some studies have shown DBT to be efficacious in treating aggression and anger dyscontrol, the overall effects of DBT on these outcomes are unknown. To address this limitation, a systematic review with meta-analysis was conducted on 34 studies (N = 2536) published in PsycINFO and PubMed between January 1994 and February 2022 assessing the effect of DBT on anger and/or aggression. Included studies were empirical research articles published in a peer-reviewed journal and assessed the delivery of DBT on quantitative outcome measures of anger or aggression. Included studies delivered the standard outpatient DBT program or DBT adapted for the population and treatment setting, though all studies included the core components of DBT. Risk of publication bias was assessed. Results demonstrated that DBT significantly reduced anger (Hedge's G = -0.21, 95% CI [-0.32, -0.11]) independent of study design and participant variables, though longer treatment duration was associated with greater reductions in anger. There was also a non-significant trend for DBT in reducing aggression (Hedge's G = -0.10, 95% CI [-0.21, 0.00]). Findings from this study suggest that DBT demonstrates efficacy in reducing dysregulated anger transdiagnostically.

Gender Differences in the Relationship between Anger and Aggressive Behavior.

Evidence is mixed regarding differences in prevalence of aggressive behavior, with many (though not all) studies suggesting that men are more aggressive than women. Furthermore, while aggression often occurs in response to provocation-induced anger, this relationship may be stronger for men; women may be more likely to engage in non-aggressive (e.g., affiliative) behaviors in response to provocation, particularly at low-level provocation. This study examined gender differences in aggression as well as differences in the relationship between anger and aggression for men and women. Adults (N = 424) participated in a behavioral aggression task, and a subset of participants (n = 304) completed a questionnaire assessing trait levels of anger as part of a larger study at a large midwestern university. Results indicated that while men and women aggressed at similar levels, aggression was significantly associated with trait anger for men only, at low levels of provocation, with only a trending relationship for high provocation. This suggests that while men and women may be equally aggressive in certain situations, this behavior may be differentially associated with anger.

Computational ECG mapping and respiratory gating to optimize stereotactic ablative radiotherapy workflow for refractory ventricular tachycardia.

BACKGROUND: Stereotactic ablative radiotherapy (SAbR) is an emerging therapy for refractory ventricular tachycardia (VT). However, the current workflow is complicated, and the precision and safety in patients with significant cardiorespiratory motion and VT targets near the stomach may be suboptimal. OBJECTIVE: We hypothesized that automated 12-lead electrocardiogram (ECG) mapping and respiratory-gated therapy may improve the ease and precision of SAbR planning and facilitate safe radiation delivery in patients with refractory VT. METHODS: Consecutive patients with refractory VT were studied at 2 hospitals. VT exit sites were localized using a 3-D computational ECG algorithm noninvasively and compared to available prior invasive mapping. Radiotherapy (25 Gy) was delivered at end-expiration when cardiac respiratory motion was ≥0.6 cm or targets were ≤2 cm from the stomach. RESULTS: In 6 patients (ejection fraction 29% ± 13%), 4.2 ± 2.3 VT morphologies per patient were mapped. Overall, 7 out of 7 computational ECG mappings (100%) colocalized to the identical cardiac segment when prior invasive electrophysiology study was available. Respiratory gating was associated with smaller planning target volumes compared to nongated volumes (71 ± 7 vs 153 ± 35 cc, P < .01). In 2 patients with inferior wall VT targets close to the stomach (6 mm proximity) or significant respiratory motion (22 mm excursion), no GI complications were observed at 9- and 12-month follow-up. Implantable cardioverter-defibrillator shocks decreased from 23 ± 12 shocks/patient to 0.67 ± 1.0 (P < .001) post-SAbR at 6.0 ± 4.9 months follow-up. CONCLUSIONS: A workflow including computational ECG mapping and protocol-guided respiratory gating is feasible, is safe, and may improve the ease of SAbR planning. Studies to validate this workflow in larger populations are required.

Feasibility and Significance of Dose Adaptation via Linear Couch Translations to Correct for Rotational Shifts During Frameless Brain Radiosurgery with the Gamma Knife Icon™.

OBJECTIVE: The present study aimed to examine the technical feasibility and effectiveness of adapting the radiation dose distributions with three-dimensional (3D) linear couch translations in contrast to full six-dimensional couch maneuvers to correct for rotational shifts during frameless radiosurgical treatment with the Gamma Knife Icon™ (Elekta AB; Stockholm, Sweden). METHODS: The original magnetic resonance images used for radiosurgery treatment planning (15 targets) were digitally processed to simulate rotational shifts of ±1, ±2, ±3, ±5, and ±10 degrees in the transverse plane and imported back into Leksell GammaPlan® (Elekta AB), creating "uncorrected" treatment plans. In addition, geometrically optimized 3D translation shifts were consequently applied to each isocenter in all "uncorrected" treatment plans to account for systematically introduced rotational shifts and to produce "corrected" treatment plans. The differences in the dose distribution between the original treatment plans and the "uncorrected" and "corrected" treatment plans were calculated and compared at each rotational shift position. RESULTS: The "uncorrected" treatment plans resulted in a significant deterioration in target coverage (by 8-72%) and selectivity (by 2-42%), with some targets being missed completely with rotations of ±3 or more degrees. In contrast, in all "corrected" treatment plans, the average decreases in target coverage and selectivity were only 1% (maximum values 4-5%). CONCLUSION: Applications of 3D linear couch translations successfully overcome gross uncertainties in dose distributions caused by up to ±10 degrees of rotational shifts in a target. As a result, rapid dose adaptation with 3D couch translations is unique and effective for frameless radiosurgery with the Gamma Knife Icon™.

Relationships between Non-Suicidal Self-Injury and Other Maladaptive Behaviors: Beyond Difficulties in Emotion Regulation.

Non-suicidal self-injury (NSSI) co-occurs with both other maladaptive behaviors (e.g., aggression) and emotion dysregulation. However, the extent to which these maladaptive behaviors are linked to NSSI independent of emotion dysregulation is unclear. The present study examined relationships between NSSI and six other maladaptive behaviors among university undergraduates. When controlling for demographic variables, emotion dysregulation, and other maladaptive behaviors, binge eating, purging, illicit drug use, and physical aggression were each related to lifetime NSSI history and/or severity. No maladaptive behaviors were significantly related to the presence of current diagnostic-level NSSI in these multivariate analyses. Results suggest that some maladaptive behaviors may relate uniquely to NSSI risk independent of emotion dysregulation, highlighting the importance of considering such behaviors in self-injury assessment and treatment.

Studying pre-treatment and ketamine-induced changes in white matter microstructure in the context of ketamine's antidepressant effects.

Ketamine is increasingly being used as a therapeutic for treatment-resistant depression (TRD), yet the effects of ketamine on the human brain remain largely unknown. This pilot study employed diffusion magnetic resonance imaging (dMRI) to examine relationships between ketamine treatment and white matter (WM) microstructure, with the aim of increasing the current understanding of ketamine's neural mechanisms of action in humans. Longitudinal dMRI data were acquired from 13 individuals with TRD two hours prior to (pre-infusion), and four hours following (post-infusion), an intravenous ketamine infusion. Free-water imaging was employed to quantify cerebrospinal fluid-corrected mean fractional anisotropy (FA) in 15 WM bundles pre- and post-infusion. Analyses revealed that higher pre-infusion FA in the left cingulum bundle and the left superior longitudinal fasciculus was associated with greater depression symptom improvement 24 h post-ketamine. Moreover, four hours after intravenous administration of ketamine, FA rapidly increased in numerous WM bundles in the brain; this increase was significantly associated with 24 h symptom improvement in select bundles. Overall, the results of this preliminary study suggest that WM properties, as measured by dMRI, may have a potential impact on clinical improvement following ketamine. Ketamine administration additionally appears to be associated with rapid WM diffusivity changes, suggestive of rapid changes in WM microstructure. This study thus points to pre-treatment WM structure as a potential factor associated with ketamine's clinical efficacy, and to post-treatment microstructural changes as a candidate neuroimaging marker of ketamine's cellular mechanisms.

Contributions of posttraumatic stress disorder (PTSD) and mild TBI (mTBI) history to suicidality in the INTRuST consortium.

OBJECTIVE: Mild TBI (mTBI) and posttraumatic stress disorder (PTSD) are independent risk factors for suicidal behaviour (SB). Further, co-occurring mTBI and PTSD increase one's risk for negative health and psychiatric outcomes. However, little research has examined the role of comorbid mTBI and PTSD on suicide risk. METHODS: The present study utilized data from the Injury and TRaUmatic STress (INTRuST) Consortium to examine the prevalence of suicidal ideation (SI) and behaviours among four groups: 1) comorbid mTBI+PTSD, 2) PTSD only, 3) mTBI only, and 4) healthy controls. RESULTS: Prevalence of lifetime SI, current SI, and lifetime SB for individuals with mTBI+PTSD was 40%, 25%, and 19%, respectively. Prevalence of lifetime SI, current SI, and lifetime SB for individuals with PTSD only was 29%, 11%, and 11%, respectively. Prevalence of lifetime SI, current SI, and lifetime SB for individuals with mTBI only was 14%, 1%, and 2%, respectively. Group comparisons showed that individuals with mTBI alone experienced elevated rates of lifetime SI compared to healthy controls. History of mTBI did not add significantly to risk for suicidal ideation and behaviour beyond what is accounted for by PTSD. CONCLUSION: Findings suggest that PTSD seems to be driving risk for suicidal behaviour.

Optimizing beam models for dosimetric accuracy over a wide range of treatments.

This work presents a systematic approach for testing a dose calculation algorithm over a variety of conditions designed to span the possible range of clinical treatment plans. Using this method, a TrueBeam STx machine with high definition multi-leaf collimators (MLCs) was commissioned in the RayStation treatment planning system (TPS). The initial model parameters values were determined by comparing TPS calculations with standard measured depth dose and profile curves. The MLC leaf offset calibration was determined by comparing measured and calculated field edges utilizing a wide range of MLC retracted and over-travel positions. The radial fluence was adjusted using profiles through both the center and corners of the largest field size, and through measurements of small fields that were located at highly off-axis positions. The flattening filter source was adjusted to improve the TPS agreement for the output of MLC-defined fields with much larger jaw openings. The MLC leaf transmission and leaf end parameters were adjusted to optimize the TPS agreement for highly modulated intensity-modulated radiotherapy (IMRT) plans. The final model was validated for simple open fields, multiple field configurations, the TG 119 C-shape target test, and a battery of clinical IMRT and volumetric-modulated arc therapy (VMAT) plans. The commissioning process detected potential dosimetric errors of over 10% and resulted in a final model that provided in general 3% dosimetric accuracy. This study demonstrates the importance of using a variety of conditions to adjust a beam model and provides an effective framework for achieving high dosimetric accuracy.

Understanding the effects of emotional reactivity on depression and suicidal thoughts and behaviors: Moderating effects of childhood adversity and resilience.

BACKGROUND: Early adulthood is a period of increased risk for depression and suicide. Emotional reactivity (a tendency to react to stress with increases in negative affect and maladaptive interpretations of events) is an important risk factor for these outcomes that has been under-studied. We hypothesized that elevated emotional reactivity would be associated with higher levels of depressive symptoms and suicidal thoughts and behaviors. Further, we hypothesized that experiences of childhood maltreatment would amplify this relationship, whereas the presence of resilience would act as a buffer. METHODS: 1703 young adults (Mean Age = 19.56 years), 71% female) completed well-validated self-report questionnaires at a single time point. RESULTS: Higher emotional reactivity was directly associated with higher levels of depressive symptoms and suicidal thoughts and behaviors. Further, resilience levels significantly moderated the relationships between emotional reactivity and depressive symptoms and suicidal thoughts and behaviors. Finally, childhood trauma significantly moderated the relationship between emotional reactivity and suicidal thoughts and behaviors only. LIMITATIONS: This study was cross-sectional in design and relied upon self-report measures only. CONCLUSIONS: The current study demonstrates an association between emotional reactivity, depressive symptoms, and suicidal thoughts and behaviors during emerging adulthood. Whereas a history of childhood maltreatment may amplify the relationship between emotional reactivity, depression, and suicidal thoughts and behaviors, certain qualities associated with resilience may buffer against the effects of emotional reactivity. Future studies can identify the resilience-promoting factors that are most protective and develop and test interventions that can potentially augment those factors.

Evaluating the impact of extended field-of-view CT reconstructions on CT values and dosimetric accuracy for radiation therapy.

PURPOSE: Wide bore CT scanners use extended field-of-view (eFOV) reconstruction algorithms to attempt to recreate tissue truncated due to large patient habitus. Radiation therapy planning systems rely on accurate CT numbers in order to correctly plan and calculate radiation dose. This study looks at the impact of eFOV reconstructions on CT numbers and radiation dose calculations in real patient geometries. METHODS: A large modular phantom based on real patient geometries was created to surround a CIRS Model 062M phantom. The modular sections included a smooth patient surface, a skin fold in the patient surface, and the addition of arms for simulation of the patient in arms up or arms down position. This phantom was used to evaluate the accuracy of CT numbers for three extended FOV algorithms implemented on Siemens CT scanners: eFOV, HDFOV, and HDProFOV. Six different configurations of the phantoms were scanned and images were reconstructed for the three different extended FOV algorithms. The CIRS phantom inserts and overall phantom geometry were contoured in each image, and the Hounsfield units (HU) numbers were compared to an image of the phantom within the standard scan FOV (sFOV) without the modular sections. To evaluate the effect on dose calculations, six radiotherapy patients previously treated at our institution (three head and neck and three chest/pelvis) whose body circumferences extended past the 50 cm sFOV in the treatment planning CT were used. Images acquired on a Siemens Sensation Open scanner were reconstructed using sFOV, eFOV and HDFOV algorithms. A physician and dosimetrist identified the radiation target, critical organs, and external patient contour. A benchmark CT was created for each patient, consisting of an average of the 3 CT reconstructions with a density override applied to regions containing truncation artifacts. The benchmark CT was used to create an optimal radiation treatment plan. The plan was copied onto each CT reconstruction without density override and dose was recalculated. RESULTS: Tissue extending past the sFOV impacts the HU numbers for tissues inside and outside the sFOV when using extended FOV reconstructions. On average, the HU for all CIRS density inserts in the arms up (arms down) position varied by 43 HU (67 HU), 39 HU (73 HU), and 18 HU (51 HU) for the eFOV, HDFOV, and HDProFOV scans, respectively. In the patient dose calculations, patients with a smooth patient contour had the least deviation from the benchmark in the HDFOV (0.1-0.5%) compared to eFOV (0.4-1.8%) reconstructions. In cases with large amounts of tissue and irregular skin folds, the eFOV deviated the least from the benchmark (range 0.2-0.6% dose difference) compared to HDFOV (range 1.3-1.8% dose difference). CONCLUSIONS: All reconstruction algorithms demonstrated good CT number accuracy in the center of the image. Larger artifacts are seen near and extending outside the scan FOV, however, dose calculations performed using typical beam arrangements using the extended FOV reconstructions were still mostly within 2.5% of best estimated reference values.

A continuous arc delivery optimization algorithm for CyberKnife m6.

PURPOSE: This study aims to reduce the delivery time of CyberKnife m6 treatments by allowing for noncoplanar continuous arc delivery. To achieve this, a novel noncoplanar continuous arc delivery optimization algorithm was developed for the CyberKnife m6 treatment system (CyberArc-m6). METHODS AND MATERIALS: CyberArc-m6 uses a five-step overarching strategy, in which an initial set of beam geometries is determined, the robotic delivery path is calculated, direct aperture optimization is conducted, intermediate MLC configurations are extracted, and the final beam weights are computed for the continuous arc radiation source model. This algorithm was implemented on five prostate and three brain patients, previously planned using a conventional step-and-shoot CyberKnife m6 delivery technique. The dosimetric quality of the CyberArc-m6 plans was assessed using locally confined mutual information (LCMI), conformity index (CI), heterogeneity index (HI), and a variety of common clinical dosimetric objectives. RESULTS: Using conservative optimization tuning parameters, CyberArc-m6 plans were able to achieve an average CI difference of 0.036 ± 0.025, an average HI difference of 0.046 ± 0.038, and an average LCMI of 0.920 ± 0.030 compared with the original CyberKnife m6 plans. Including a 5 s per minute image alignment time and a 5-min setup time, conservative CyberArc-m6 plans achieved an average treatment delivery speed up of 1.545x ± 0.305x compared with step-and-shoot plans. CONCLUSIONS: The CyberArc-m6 algorithm was able to achieve dosimetrically similar plans compared to their step-and-shoot CyberKnife m6 counterparts, while simultaneously reducing treatment delivery times.

Commissioning and Evaluation of an Electronic Portal Imaging Device-Based In-Vivo Dosimetry Software.

This study reports on our experience with the in-vivo dose verification software, EPIgray® (DOSIsoft, Cachan, France). After the initial commissioning process, clinical experiments on phantom treatments were evaluated to assess the level of accuracy of the electronic portal imaging device (EPID) based in-vivo dose verification. EPIgray was commissioned based on the company's instructions. This involved ion chamber measurements and portal imaging of solid water blocks of various thicknesses between 5 and 35 cm. Field sizes varied between 2 x 2 cm2 and 20 x 20 cm2. The determined conversion factors were adjusted through an additional iterative process using treatment planning system calculations. Subsequently, evaluation was performed using treatment plans of single and opposed beams, as well as intensity modulated radiotherapy (IMRT) plans, based on recommendations from the task group report TG-119 to test for dose reconstruction accuracy. All tests were performed using blocks of solid water slabs as a phantom. For single square fields, the dose at isocenter was reconstructed within 3% accuracy in EPIgray compared to the treatment planning system dose. Similarly, the relative deviation of the total dose was accurately reconstructed within 3% for all IMRT plans with points placed inside a high-dose region near the isocenter. Predictions became less accurate than < 5% when the evaluation point was outside the treatment target. Dose at points 5 cm or more away from the isocenter or within an avoidance structure was reconstructed less reliably. EPIgray formalism accuracy is adequate for an efficient error detection system with verifications performed in high-dose volumes. It provides immediate intra-fractional feedback on the delivery of treatment plans without affecting the treatment beam. Besides the EPID, no additional hardware is required. The software evaluates local point dose measurements to verify treatment plan delivery and patient positioning within 5% accuracy, depending on the placement of evaluation points.

Deep nets vs expert designed features in medical physics: An IMRT QA case study.

PURPOSE: The purpose of this study was to compare the performance of Deep Neural Networks against a technique designed by domain experts in the prediction of gamma passing rates for Intensity Modulated Radiation Therapy Quality Assurance (IMRT QA). METHOD: A total of 498 IMRT plans across all treatment sites were planned in Eclipse version 11 and delivered using a dynamic sliding window technique on Clinac iX or TrueBeam Linacs. Measurements were performed using a commercial 2D diode array, and passing rates for 3%/3 mm local dose/distance-to-agreement (DTA) were recorded. Separately, fluence maps calculated for each plan were used as inputs to a convolution neural network (CNN). The CNNs were trained to predict IMRT QA gamma passing rates using TensorFlow and Keras. A set of model architectures, inspired by the convolutional blocks of the VGG-16 ImageNet model, were constructed and implemented. Synthetic data, created by rotating and translating the fluence maps during training, was created to boost the performance of the CNNs. Dropout, batch normalization, and data augmentation were utilized to help train the model. The performance of the CNNs was compared to a generalized Poisson regression model, previously developed for this application, which used 78 expert designed features. RESULTS: Deep Neural Networks without domain knowledge achieved comparable performance to a baseline system designed by domain experts in the prediction of 3%/3 mm Local gamma passing rates. An ensemble of neural nets resulted in a mean absolute error (MAE) of 0.70 ± 0.05 and the domain expert model resulted in a 0.74 ± 0.06. CONCLUSIONS: Convolutional neural networks (CNNs) with transfer learning can predict IMRT QA passing rates by automatically designing features from the fluence maps without human expert supervision. Predictions from CNNs are comparable to a system carefully designed by physicist experts.

Correcting TG 119 confidence limits.

PURPOSE: Task Group 119 (TG-119) has been adopted for evaluating the adequacy of intensity-modulated radiation therapy (IMRT) commissioning and for establishing patient-specific IMRT quality assurance (QA) passing criteria in clinical practice. TG-119 establishes 95% confidence limits (CLs), which help clinics identify systematic IMRT QA errors and identify outliers. In TG-119, the 95% CLs are established by fitting the Gamma Γ analysis passing rate results to an assumed distribution, then calculating the limit in which 95% of the data fall. CLs for a given dataset will depend greatly on the type of distribution used, and those determined by following the TG-119 guidelines are only valid if the underlying data follows a Gaussian distribution. Gaussian distributions assume symmetry about the mean, which would imply the possibility of negative Γ analysis failing rates. This study demonstrates that the gamma distribution is a more reasonable assumption for establishing CLs than the Gaussian distribution used in TG-119. Thus, the gamma distribution is suggested as a replacement to the conventional Gaussian statistical model used in TG-119. MATERIALS AND METHODS: The moments estimator (ME) for the gamma family is used to obtain the CLs of the failing rates for all Γ analysis criteria. To demonstrate the congruence of the gamma distribution, the root mean squared error and the CL values for the MEs of the gamma and the Gaussian families were compared. RESULTS: In this study, the empirical 95% CLs generated using 302 plans represent the ground truth, which resulted in a 91.83% passing rate using 3%/3 mm error local criteria. The gamma distribution underestimates the 95% CL by 0.09%, while the Gaussian distribution overestimates the 95% CL by 4.12%. CONCLUSIONS: Although IMRT QA equipment may vary between clinics, the mathematical formalism presented in this study applies to any combination of planning and delivery systems. This study has demonstrated that a gamma distribution should be favored over a Gaussian distribution when establishing CLs for IMRT QA.

Qigong and Tai-Chi for Mood Regulation.

Qigong and Tai-Chi are traditional self-healing, self-cultivation exercises originating in ancient China. These exercises are characterized by coordinated body posture and movements, deep rhythmic breathing, meditation, and mental focus based on traditional Chinese medicine theories. Although the exact mechanisms of Qigong's and Tai-Chi's effects on physical and mental well-being are unknown, these practices may be viewed as meditative movements and share many of the healing elements observed in mindfulness meditation. Clinical studies including randomized controlled trials and meta-analyses have shown that both Qigong and Tai-Chi have beneficial effects on psychological well-being and reduce symptoms of anxiety and depression. Qigong and Tai-Chi frequently involve anchoring attention to interoceptive sensations related to breath or other parts of the body, which has been shown to enhance nonreactivity to aversive thoughts and impulses. Preliminary studies suggest that the slow movements in Qigong and Tai-Chi with slowing of breath frequency could alter the autonomic system and restore homeostasis, attenuating stress related to hypothalamus-pituitary-adrenal axis reactivity and modulating the balance of the autonomic nervous system toward parasympathetic dominance. Qigong's and Tai-Chi's effects on emotion regulation could occur through changes in multiple prefrontal regions, the limbic system, and the striatum or in the expression of genes linked to inflammatory responses and stress-related pathways.

Improved rectal dosimetry with the use of SpaceOAR during high-dose-rate brachytherapy.

PURPOSE: Hydrogel spacers have been suggested to limit rectal radiation dose with improvements in clinical outcomes in patients undergoing external beam radiation treatment for prostate cancer. No studies to date have assessed the utility and dosimetric effect of SpaceOAR (Augmenix, Inc, Waltham, MA), the only Food and Drug Administration-approved hydrogel rectal spacer, for high-dose-rate (HDR) brachytherapy. METHODS: Eighteen consecutive patients scheduled for HDR brachytherapy in the treatment of prostate cancer underwent transperineal ultrasound-guided placement of 10 cc of SpaceOAR hydrogel following catheter implantation. Treatment plans were generated using an inverse planning simulated annealing algorithm. Rectal dosimetry for these 18 patients was compared with the 36 preceding patients treated with HDR brachytherapy without SpaceOAR. RESULTS: Fifty-four plans were analyzed. There was no difference in age, pretreatment prostate-specific antigen, Gleason score, clinical stage, prostate volume, or contoured rectal volume between those who received SpaceOAR and those who did not. Patients who received SpaceOAR hydrogel had significantly lower dose to the rectum as measured by percent of contoured organ at risk (median, V80 < 0.005% vs. 0.010%, p = 0.003; V75 < 0.005% vs. 0.14%, p < 0.0005; V70 0.09% vs. 0.88%, p < 0.0005; V60 = 1.16% vs. 3.08%, p < 0.0005); similar results were seen for rectal volume in cubic centimeters. One patient who received SpaceOAR developed a perineal abscess 1 month after treatment. CONCLUSIONS: Transperineal insertion of SpaceOAR hydrogel at the time of HDR brachytherapy is feasible and decreases rectal radiation dose. Further investigation is needed to assess the clinical impact of this dosimetric improvement and potential toxicity reduction.