Robustness analysis of surface-guided DIBH left breast radiotherapy: personalized dosimetric effect of real intrafractional motion within the beam gating thresholds

PURPOSE

The robustness of surface-guided (SG) deep-inspiration breath-hold (DIBH) radiotherapy (RT) for left breast cancer was evaluated by investigating any potential dosimetric effects due to the residual intrafractional motion allowed by the selected beam gating thresholds. The potential reduction of DIBH benefits in terms of organs at risk (OARs) sparing and target coverage was evaluated for conformational (3DCRT) and intensity-modulated radiation therapy (IMRT) techniques.

METHODS

A total of 192 fractions of SGRT DIBH left breast 3DCRT treatment for 12 patients were analyzed. For each fraction, the average of the real-time displacement between the isocenter on the daily reference surface and on the live surface ("SGRT shift") during beam-on was evaluated and applied to the original plan isocenter. The dose distribution for the treatment beams with the new isocenter point was then calculated and the total plan dose distribution was obtained by summing the estimated perturbed dose for each fraction. Then, for each patient, the original plan and the perturbed one were compared by means of Wilcoxon test for target coverage and OAR dose-volume histogram (DVH) metrics. A global plan quality score was calculated to assess the overall plan robustness against intrafractional motion of both 3DCRT and IMRT techniques.

RESULTS

Target coverage and OAR DVH metrics did not show significant variations between the original and the perturbed plan for the IMRT techniques. 3DCRT plans showed significant variations for the left descending coronary artery (LAD) and the humerus only. However, none of the dose metrics exceeded the mandatory dose constraints for any of the analyzed plans. The global plan quality analysis indicated that both 3DCRT and IMRT techniques were affected by the isocenter shifts in the same way and, generally, the residual isocenter shifts more likely tend to worsen the plan in all cases.

CONCLUSION

The DIBH technique proved to be robust against residual intrafractional isocenter shifts allowed by the selected SGRT beam-hold thresholds. Small-volume OARs located near high dose gradients showed significant marginal deteriorations in the perturbed plans with the 3DCRT technique only. Global plan quality was mainly influenced by patient anatomy and treatment beam geometry rather than the technique adopted.

Surface-guided DIBH radiotherapy for left breast cancer: impact of different thresholds on intrafractional motion monitoring and DIBH stability

PURPOSE

To compare two left breast cancer patient cohorts (tangential vs. locoregional deep-inspiration breath-hold - DIBH treatment) with different predefined beam gating thresholds and to evaluate their impact on motion management and DIBH stability.

METHODS

An SGRT-based clinical workflow was adopted for the DIBH treatment. Intrafractional monitoring was performed by tracking both the respiratory signal and the real-time displacement between the isocenter on the daily reference surface and on the live surface ("SGRT shift"). Beam gating tolerances were 5 mm/4 mm for the SGRT shifts and 5 mm/3 mm for the gating window amplitude for breast tangential and breast + lymph nodes locoregional treatments, respectively. A total of 24 patients, 12 treated with a tangential technique and 12 with a locoregional technique, were evaluated for a total number of 684 fractions. Statistical distributions of SGRT shift and respiratory signal for each treatment fraction, for each patient treatment, and for the two population samples were generated.

RESULTS

Lateral cumulative distributions of SGRT shifts for both locoregional and tangential samples were consistent with a null shift, whereas longitudinal and vertical ones were slightly negative (mean values < 1 mm). The distribution of the percentage of beam on time with SGRT shift > 3 mm, > 4 mm, or > 5 mm was extended toward higher values for the tangential sample than for the locoregional sample. The variability in the DIBH respiration signal was significantly greater for the tangential sample.

CONCLUSION

Different beam gating thresholds for surface-guided DIBH treatment of left breast cancer can impact motion management and DIBH stability by reducing the frequency of the maximum SGRT shift and increasing respiration signal stability when tighter thresholds are adopted.

A Structured Intervention to Support Early Palliative Care Conversations for Oncology Patients - A Qualitative Feasibility Study

AIMS

For patients with advanced cancer, early access to palliative care can have numerous psychosocial and disease management benefits. However, it can be difficult for clinicians to initiate these initial conversations about palliative care. The aim of the present study was to beta test an intervention to facilitate timely conversations about palliative care between patients and clinicians.

MATERIALS AND METHODS

The study reported forms one stage of a complex intervention development study following Medical Research Council guidance for developing complex interventions. Feasibility was explored from patient and clinician perspectives in an oncology outpatient setting.

RESULTS

Sixteen patients and 18 clinicians participated. Three phases of the intervention were assessed through patient and clinician interviews. The analysis produced three themes in each phase: (i) Preparation (patient preparedness; healthcare professionals' perspectives on palliative care; administration, data and communication); (ii) STEP consultation (defining perspectives on palliative care; how palliative care fits with the current treatment plan; permission to explore future care); (iii) Outcomes (changes in perspective and approaches to coping; opening the door to future conversations; referrals and involvement of palliative services).

CONCLUSIONS

The STEP intervention generated important early conversations about end-of-life care that may otherwise not have occurred. No patients regretted having the STEP consultation, which resulted in palliative care referrals for some. Others felt better informed about the support services available and better able to have further conversations. Participating clinicians found the structured conversation guide useful, as it acted as a prompt for areas to cover, as well as providing an explicit way to open discussion about difficult topics.

Oxidative stress and viral Infections: rationale, experiences, and perspectives on N-acetylcysteine

This article explores current evidence on the role of oxidative stress in viral infections, and on the use of antioxidant drugs as adjunctive treatment. MEDLINE/PubMed was searched for appropriate keywords, and preclinical and clinical studies with reviews were retrieved and examined by authors. Old and current evidence shows that GSH content reduction is the main mechanism of redox imbalance in viral-infected cells. Clinical studies found that GSH levels are depleted in patients with viral infections such as HIV and SARS-CoV. Viral infections activate inflammation through different pathways, and several of these mechanisms are related to oxidative stress. NAC is a precursor of GSH, and many of its intracellular effects are mediated by GSH replenishment, but it also activates some anti-inflammatory mechanisms. NAC has an excellent safety profile and better oral and topical bioavailability than GSH. These characteristics make NAC a suitable option as a repurposed drug. Adjunctive antioxidant treatment may improve the outcomes of antiviral therapies. Current evidence supports the rationale for this practice and some clinical experience showed encouraging results.

Prevalence and features of delirium in older patients admitted to rehabilitation facilities: a multicenter study

BACKGROUND

Delirium is thought to be common across various settings of care; however, still little research has been conducted in rehabilitation.

AIM

We investigated the prevalence of delirium, its features and motor subtypes in older patients admitted to rehabilitation facilities during the three editions of the "Delirium Day project".

METHODS

We conducted a cross-sectional study in which 1237 older patients (age ≥ 65 years old) admitted to 50 Italian rehabilitation wards during the three editions of the "Delirium Day project" (2015 to 2017) were included. Delirium was evaluated through the 4AT and its motor subtype with the Delirium Motor Subtype Scale.

RESULTS

Delirium was detected in 226 patients (18%), and the most recurrent motor subtype was mixed (37%), followed by hypoactive (26%), hyperactive (21%) and non-motor one (16%). In a multivariate Poisson regression model with robust variance, factors associated with delirium were: disability in basic (PR 1.48, 95%CI: 1.17-1.9, p value 0.001) and instrumental activities of daily living (PR 1.58, 95%CI: 1.08-2.32, p value 0.018), dementia (PR 2.10, 95%CI: 1.62-2.73, p value < 0.0001), typical antipsychotics (PR 1.47, 95%CI: 1.10-1.95, p value 0.008), antidepressants other than selective serotonin reuptake inhibitors (PR 1.3, 95%CI: 1.02-1.66, p value 0.035), and physical restraints (PR 2.37, 95%CI: 1.68-3.36, p value < 0.0001).

CONCLUSION

This multicenter study reports that 2 out 10 patients admitted to rehabilitations had delirium on the index day. Mixed delirium was the most prevalent subtype. Delirium was associated with unmodifiable (dementia, disability) and modifiable (physical restraints, medications) factors. Identification of these factors should prompt specific interventions aimed to prevent or mitigate delirium.

The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017

Introduction

Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium.

Methods

The analyses were conducted employing the cross-sectional “Delirium Day” initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + score at the 4-AT scale. Low skeletal muscle mass was operationally defined as calf circumference ≤ 34 cm in males and ≤ 33 cm in females. Logistic regression models were used to investigate the association between low skeletal muscle mass and delirium. The discriminative ability of calf circumference was evaluated using non-parametric ROC analyses.

Results

A sample of 1675 patients was analyzed. In total, 73.6% of participants had low skeletal muscle mass and 24.1% exhibited delirium. Low skeletal muscle mass and delirium showed an independent association (OR: 1.50; 95% CI 1.09–2.08). In the subsample of patients without a diagnosis of dementia, the inclusion of calf circumference in a model based on age and sex significantly improved its discriminative accuracy [area under the curve (AUC) 0.69 vs 0.57, p < 0.001].

Discussion and conclusion

Low muscle mass is independently associated with delirium. In patients without a previous diagnosis of dementia, calf circumference may help to better identify those who develop delirium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01950-8.

Synchronous vs. non-synchronous imitation: Using dance to explore interpersonal coordination during observational learning

Observational learning can enhance the acquisition and performance quality of complex motor skills. While an extensive body of research has focused on the benefits of synchronous (i.e., concurrent physical practice) and non-synchronous (i.e., delayed physical practice) observational learning strategies, the question remains as to whether these approaches differentially influence performance outcomes. Accordingly, we investigate the differential outcomes of synchronous and non-synchronous observational training contexts using a novel dance sequence. Using multidimensional cross-recurrence quantification analysis, movement time-series were recorded for novice dancers who either synchronised with (n = 22) or observed and then imitated (n = 20) an expert dancer. Participants performed a 16-count choreographed dance sequence for 20 trials assisted by the expert, followed by one final, unassisted performance trial. Although end-state performance did not significantly differ between synchronous and non-synchronous learners, a significant decline in performance quality from imitation to independent replication was shown for synchronous learners. A non-significant positive trend in performance accuracy was shown for non-synchronous learners. For all participants, better imitative performance across training trials led to better end-state performance, but only for the accuracy (and not timing) of movement reproduction. Collectively, the results suggest that synchronous learners came to rely on a real-time mapping process between visual input from the expert and their own visual and proprioceptive intrinsic feedback, to the detriment of learning. Thus, the act of synchronising alone does not ensure an appropriate training context for advanced sequence learning.

Frequency and clinical correlates of bipolar features in acute coronary syndrome patients

Background:

Depression and acute coronary syndrome (ACS) are both extremely prevalent diseases. Studies aimed at evaluating whether depression is an independent risk factor for cardiac events provided no definitive results. In most of these studies, depression has been broadly defined with no differentiation between unipolar (MDD) versus bipolar forms (BD). The aim of this study was to evaluate the frequency of DSM-IV BD (bipolar I and bipolar II subtypes, cyclothymia), as well as temperamental or isolated bipolar features in a sample of 171 patients hospitalized for ACS. We also explored whether these psychopathological conditions were associated with some clinical characteristics of ACS.

Methods:

Patients with ACS admitted to three neighboring Cardiac Intensive Care Units (CICUs) in a 12-month continuative period of time were eligible for inclusion if they met the criteria for either acute myocardial infarct with or without ST-segment elevation or unstable angina, verified by standard ACS criteria. All patients underwent standardized cardiological and psychopathological evaluations.

Results:

Of the 171 ACS patients enrolled, 37 patients (21.7%) were found to have a DSM-IV mood disorder. Of these, 20 (11.7%) had bipolar type I or type II or cyclothymia, while 17 (10%) were the cases of MDD. Rapid mood switches ranged from 11% of ACS patients with no mood disorders, to 47% of those with MDD to 55% of those with BD. Linear regression analysis showed that a diagnosis of BD (p = .023), but not that of MDD (p = .721), was associated with a significant younger age at the index episode of ACS. A history of previous coronary events was more frequent in ACS patients with BD than in those with MDD.

Conclusions:

Our data indicate that bipolar features and diagnosis are frequent in ACS patients. Bipolar disorder has a negative impact on cardiac symptomatology. Further research in this area is warranted.

How the detector resolution affects the clinical significance of SBRT pre-treatment quality assurance results

PURPOSE

Aim of this work was to study how the detector resolution can affect the clinical significance of SBRT pre-treatment volumetric modulated arc therapy (VMAT) verification results.

METHODS

Three detectors (PTW OCTAVIUS 4D 729, 1500 and 100 SRS) used in five configurations with different resolution were compared: 729, 729 merged, 1500, 1500 merged and 1000 SRS. Absolute local gamma passing rates of 3D pre-treatment quality assurance (QA) were evaluated for 150 dose distributions in 30 plans. Five different kinds of error were introduced in order to establish the detection sensitivity of the three devices. Percentage dosimetric differences were evaluated between planned dosevolume histogram (DVH) and patients' predicted DVH calculated by PTW DVH 4D® software.

RESULTS

The mean gamma passing rates and the standard deviations were 92.4% ± 3.7%, 94.6% ± 1.8%, 95.3% ± 4.2%, 97.4% ± 2.5% and 97.6% ± 1.4 respectively for 729, 729 merged, 1500, 1500 merged and 1000 SRS with 2% local dose/2mm criterion. The same trend was found on the sensitivity analysis: using a tight gamma analysis criterion (2%L/1mm) only the 1000 SRS detected every kind of error, while 729 and 1500 merged detected three and four kinds of error respectively. Regarding dose metrics extracted from DVH curves, D50% was within the tolerance level in more than 90% of cases only for the 1000 SRS.

CONCLUSIONS

The detector resolution can significantly affect the clinical significance of SBRT pre-treatment verification results. The choice of a detector with resolution suitable to the investigated field size is of main importance to avoid getting false positive.

Bone cement implantation syndrome: a thromboelastographic study of the effect of bone cement on coagulation

Bone cement implantation syndrome (BCIS) is a rare form of intraoperative pulmonary embolism (EP) that occurs during cementation. It can be explained by two main theories: the monomer mediated model and the mechanic model. Our goal is to evaluate thromboelastographic changes in patients undergoing surgery for femoral neck fractures. We recruited 32 patients with a femoral neck fracture. The average age was 81.91 years (range 62-95). The patients were divided in two different groups: cemented hip arthroplasty (CC, 13 patients) and other surgical non-cemented techniques (SC, non-cemented hip arthroplasty, osteosynthesis). The coagulation was evaluated by TEG in the early pre-operatory (time A) and post-operatory (time B), both on native blood and on blood added with Heparinase. We used the t-test to compare the differences between the two groups. The coagulation index CI was modified on hypercoagulability by surgery in both groups, but without statistical significance between the two groups (p>0.05). R parameter decreases between time A and time B in the same way in both groups (p>0.05). Parameter MA had no major variations between time A and B, without statistical significance (p>0.05). From our study it is evident that although the surgery would result in a change in the layout of the TEG toward hypercoagulability, this is similar both in cemented and non-cemented surgical interventions for femoral neck fractures in elderly patients. An altered coagulation does not appear to be the cause or a factor in determining the BCIS.

Unaltered Oxytocin and Vasopressin Plasma Levels in Patients with Schizophrenia After 4 Months of Daily Treatment with Intranasal Oxytocin

The neuropeptide oxytocin (OXT) has been proposed as a treatment for a number of neuropsychiatric disorders characterised by impaired social behaviour, including schizophrenia. Although several studies have reported the chronic administration of OXT to be safe and tolerable, its effects on circulating levels of OXT, as well as the related neuropeptide arginine vasopressin (AVP), have not been assessed. In the present study, in a within-subjects cross-over, double-blind, randomised controlled trial, we assayed the plasma levels of OXT and AVP in 31 patients with schizophrenia who were treated daily for 4 months with 40 IU of intranasal OXT or placebo. Our data indicate a mean ± SD baseline OXT concentration of 1.62 ± 0.68 pg/ml, as determined by radioimmunoassay, which did not display any significant variation after chronic treatment with OXT or placebo. Similarly, the mean ± SD baseline AVP value of 2.40 ± 1.26 pg/ml remained unchanged. The present study also assessed cardiovascular and body fluid indicators (osmolality, plasma sodium concentration and systolic blood pressure), as well as a parameter for food intake (body mass index), with all observed to remain stable. By reporting that daily treatment with 40 IU of intranasal OXT or placebo for 4 months does not impact on OXT and AVP plasma levels, nor on cardiovascular, body fluids and food intake parameters, the present study represents an important step towards developing OXT as a safe treatment.

Role of translocator protein (18 kDa) in adult separation anxiety and attachment style in patients with depression

BACKGROUND AND OBJECTIVES

A role for the protein that mediates the rate-limiting step of steroidogenesis, the 18 kDa Translocator Protein (TSPO), has been suggested in the pathophysiology of Adult Separation Anxiety Disorder (ASAD). It has been shown that ASAD patients have 1) low TSPO expression levels and 2) a high frequency of the allele that substitutes Ala with Thr at position 147 of TSPO. The Thr147 ASAD-associated allele has been recently related with a low pregnenolone production. The aim of the present work was to evaluate the relationship between TSPO expression levels and Ala147Thr single nucleotide polymorphism (SNP), which are the two TSPO biological parameters that we have previously examined separately. A further aim was to confirm the genetic association of Ala147Thr SNP with ASAD in an extended case-control sample and to investigate whether this SNP was related to an anxious attachment style that is thought to be connected to ASAD.

METHODS

TSPO expression levels were compared among patients with ASAD (n=26), without ASAD (n=26) and control samples (n=10) stratified into the two genotype groups: those with the Ala147 genotype (named "normal pregnenolone production") and those with the Thr147 genotype (named "reduced pregnenolone production"). The case-control genetic study included patients with (n=87) or without (n=101) ASAD and 236 controls. In the patient group, the association between the Ala147Thr SNP and an anxious attachment style was analysed by stepwise logistic regression analysis.

RESULTS

The genotype with the lowest TSPO expression levels was the "normal pregnenolone production" genotype in the ASAD group. The genetic Ala147Thr SNP confirmed an excess of the Thr147 allele in ASAD patients. Stepwise logistic regression analysis did not show an association with an anxious attachment style.

CONCLUSIONS

ASAD individuals who expressed normal TSPO levels exhibited the "reduced pregnenolone production" genotype. In contrast, the ASAD individuals with the "normal pregnenolone production" genotype expressed low TSPO levels. It is possible that low TSPO expression levels could compromise normal pregnenolone production. Such evidence may have therapeutic implications because it has been documented that drugs targeting TSPO increased pregnenolone production and have anxiolytic effects.